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Posted: 12/27/2015 2:57:27 PM EDT
[#1]
Quote HistoryQuoted: Also, how do the powdered metal metal fillers work? They add viscosity, but people also seem to use them for strength, and I've never understood how particles of anything add strength to an epoxy (as opposed to fibers, which I do understand). JB Weld is the most popular 2-part epoxy w/ a metal filler. Its properties would seem equivalent to other retail 2-part epoxies. The metal adds filler, which probably lowers JB Weld's cost, and adds marketing properties, all of which increase the profit to JB Weld. I don't see they lessen the strength - the particles are presumably not smooth, but rough, and act like small rough rocks in concrete. Something as strong as the concrete, but cheaper, and allows the concrete to bind to their crevices. Perhaps that technique could save some of the cost of new rubber - try putting small rocks in your molds. 
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Posted: 12/27/2015 3:36:31 PM EDT
[#2]
Quote HistoryQuoted:
Perhaps that technique could save some of the cost of new rubber - try putting small rocks in your molds. Yes, I've considered using sand for the areas of bulk fill, though for the moment I have more than enough scrap rubber from earlier molds. |
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Posted: 12/27/2015 4:01:15 PM EDT
[#3]
Does concrete shrink as it cures? Though the problem of getting the original lower out of the mold could be tremendous. I presume you'd line each removable section w/ wax paper or summat, as you'd not be cutting it w/ a putty knife like now.
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Posted: 12/27/2015 9:59:02 PM EDT
[#4]
I've never done a mold like this with epoxy resin and composites, all vac bagged. The reason for vac bagging is to remove trapped air which is often caused by pouring and mixing and air trapped in the fibers.
Could always try some and then vibrate it until the bubbles come out. Will turn out yellowish due to how the resin drys. Fully machinable. I'd like to try a carbon slurry but first need my supplies to make a mold. Some good long stringers should really help the rear portion strength issues. IMHO, run stringers top to bottom and front to back for strength in both directions. My poly lower on my tokarev AR is not much beefier than a normal forged in that area. Small reinforcement in the right way will have huge benefits. Higher elasticity should mean more durable and less brittle. That's good, to a point. |
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Posted: 12/28/2015 11:52:44 AM EDT
[#5]
So, hypothetically, what would happen if you used something durable for the mold. And then wrap it in something stronger like this epoxy tape?
http://www.homedepot.com/p/FiberFix-2-in-x-1-4-yds-Repair-Wrap-857101004013/204413279 |
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Posted: 12/28/2015 1:38:01 PM EDT
[#6]
Quote HistoryQuoted: So, hypothetically, what would happen if you used something durable for the mold. And then wrap it in something stronger like this epoxy tape?
http://www.homedepot.com/p/FiberFix-2-in-x-1-4-yds-Repair-Wrap-857101004013/204413279 Interesting. You're going to want to use something waterproof for the mold box; sample nearly went crazy, and wasted a great deal of rubber, w/ the Lego mold box I built for him. It can be done, but not the best. I'm more curious about reinforcing the lower w/ this tape. Have you used any of it? |
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Posted: 12/28/2015 1:42:12 PM EDT
[#7]
never used it, but I did see sample items that were wrapped at the store display. It really was surprisingly rigid for tape.
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Posted: 12/28/2015 10:13:48 PM EDT
[#8]
Im waiting for supplies but I plan to kevlar reinforce my first lower or two then off to some minor testing. Plan to add some in the area of the buffer tube ring as well as sculpt the area for added reinforcement.
Still having trouble deciding on a casting material. Is Task 15 still a favorite or too soft? Task 8? Little softer than 9 but not as soft as 15. Epoxy resin will come later. I feel like an epoxy tape could help if applied in the right spots otherwise all it does is add weight. |
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Posted: 12/28/2015 10:41:59 PM EDT
[#9]
Quote HistoryQuoted:
Still having trouble deciding on a casting material. Is Task 15 still a favorite or too soft? Epoxy resin will come later. In my opinion Task 15 is too soft unless you intend a dimensionally reinforced receiver like FP3D used, and unless you use a cassette trigger. I am reverting to Task 9 while I work though my mold problems. With the kevlar you are using, Task 9 will probably serve for your initial testing. I'm eager to learn what you come up with when you start working with epoxy resins. |
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Posted: 12/29/2015 12:12:43 AM EDT
[#10]
Quote HistoryQuoted: I feel like an epoxy tape could help if applied in the right spots otherwise all it does is add weight. I'm still trying to understand how you're wanting to use that tape stuff you linked above. |
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Posted: 12/29/2015 10:00:44 AM EDT
[#11]
Quote HistoryQuoted:
I'm still trying to understand how you're wanting to use that tape stuff you linked above. Quote HistoryQuoted:
Quoted:
I feel like an epoxy tape could help if applied in the right spots otherwise all it does is add weight. I'm still trying to understand how you're wanting to use that tape stuff you linked above. I was replying to above and being lazy, not quoting. I've spent a while with composites so some fun stuff should happen. I've been able to even make dirt bike fenders with with carbon that can be twisted by hand almost 180 degrees along the length but from end to end strong enough for me to stand on with no flex. That was with carbon, Kevlar and lots of fiberglass. Plan to make 2-3 lowers from something like task 8 or 9 with Kevlar reinforcement. Later go full composite with an epoxy resin and Kevlar. Might have to talk a buddy I to sending me some Kevlar/carbon hybrid and using a carbon slurry as the medium to bind it. Be really hard to keep bubbles at bay though. Mixing a carbon slurry by hand is just asking for bubbles. Between this and a M31 suomi build I think I'll stay busy on my rare days off. |
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Posted: 12/30/2015 2:49:39 PM EDT
[#12]
Found this thread after seeing an ad on Facebook for what looks like a new company pimping mold your own lower receivers and searching for more info on them. Anyhow you F'ers are genius and I marvel at what y'all can do!
I must have an orange one like that from the first post! |
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Posted: 12/30/2015 3:40:07 PM EDT
[#13]
Quote HistoryQuoted: Found this thread after seeing an ad on Facebook for what looks like a new company pimping mold your own lower receivers and searching for more info on them. Anyhow you F'ers are genius and I marvel at what y'all can do! I must have an orange one like that from the first post! Yeah I know the company you speak of. I mentioned them earlier in this thread. Based on their business practices I'd stay far far away. |
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Posted: 12/31/2015 3:20:34 PM EDT
[#14]
Quote HistoryQuoted:
The safety functions normally with unreinforced Task 9, so the problem seems likely isolated to possibilities 1 or 2. I will run a Task 9/fiberglass test next, tonight if I have time. Quote HistoryQuoted:
Quoted:
Several possibilities:
Just poured a Task 9 casting with no fiberglass to see if I can isolate the problem to 1 or 2. 3 could be corrected with more transverse pins through the mold to locate it better at the bottom of the box (and conceivably with pins which fit the sides of the mold box). I am increasingly convinced the problem is actually 4. The safety functions normally with unreinforced Task 9, so the problem seems likely isolated to possibilities 1 or 2. I will run a Task 9/fiberglass test next, tonight if I have time. It was a few days before I got to this test, but the fiberglass test with Task 9 worked, so it appears the problem was with Task 15. Therefore I'd reaffirm my recommendation that anyone working with Task 15 use a cassette trigger. I will continue experiments with Task 9 for now, since I'm working more on perfecting a mold than I am perfecting a finished receiver. I'd had safety problems with an earlier mold, which is one reason I went to the new mold with the fire control holes (and others) molded around pins through the receiver. Unfortunately several parts of this mold which still rely on rubber to mold small, complex voids have torn off over the course of my recent testing. These parts cause a lot of trouble between them, being small, prone to imperfect filling by the rubber to start with, and being easily torn upon demolding, especially if stray strands of fiberglass impinge on their space:
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Posted: 12/31/2015 4:02:13 PM EDT
[#15]
Skip the LRBHO alltogether?
As far as the safety detent goes, can the channel be formed by 2 pins of differing diameters, one from the top, a la CavArms, and one from the bottom as normal? |
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Posted: 1/1/2016 4:17:25 AM EDT
[#16]
Quote HistoryQuoted:
As far as the safety detent goes, can the channel be formed by 2 pins of differing diameters, one from the top, a la CavArms, and one from the bottom as normal? Forming the two diameters of that plunger hole using separate pins sounds like quite a boon, but it would require one either to forgo using a cross bolt to form the safety holes, or it would requite that bolt to be precisely drilled to fit the inner diameter pin, plus it would require some means of locating one or both pins, which is not required if a pin were ground to both diameters at proper depth and then seated in the mold with the tip locating the depth by being pressed against the pin. |
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Posted: 1/1/2016 8:27:45 AM EDT
[#17]
Cotter pin?
Posted Via AR15.Com Mobile |
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Posted: 1/6/2016 5:00:14 PM EDT
[#18]
So how's the molding going... any new developments?
And, bump. |
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Posted: 1/7/2016 2:42:27 AM EDT
[#19]
I've had to suspend work for a few weeks. In the meantime I will be placing an order with Fastenal for more pins to use in the mold, to form the bolt-stop plunger hole and roll pin hole, to form the safety, and then several pins simply to add to the rubber for more dimensional control of the mold. The idea would be to pin each piece of the mold to another piece in as many places as proves convenient.
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Posted: 1/7/2016 10:00:27 PM EDT
[#20]
Well I decided do to the shear cool factor of this thread to try my hand at a 3 piece mold. I decided to go with a billet 80% lower I have yet to mess with as the master and bond a fire control pocket from a spikes onto the mold. During the bonding pour I had some leak by that distorted the buffer threads, so I'm going to remove them from the center section and relocate them to the right side mold instead. That being said I poured a lower anyway because...well why not. Turned out ok for a trial run, couple of flaws due to my pocket knife flash removal and clay in the mold I failed to remove.
Left side: 
Right side: 
Center section left view: 
Center section right view: 
Center installed: 
Test run lower: 
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Posted: 1/7/2016 11:23:14 PM EDT
[#21]
Quote HistoryQuoted:
Well I decided do to the shear cool factor of this thread to try my hand at a 3 piece mold. I decided to go with a billet 80% lower I have yet to mess with as the master and bond a fire control pocket from a spikes onto the mold. During the bonding pour I had some leak by that distorted the buffer threads, so I'm going to remove them from the center section and relocate them to the right side mold instead. That being said I poured a lower anyway because...well why not. Turned out ok for a trial run, couple of flaws due to my pocket knife flash removal and clay in the mold I failed to remove. First, fantastic to see someone else diving into this. Second, can you relate the details of how you went about that mold? From the indentations in the outside pieces, I'm assuming your method has to do with a generous dollop of mold release, which isn't something I've been brave enough to try yet. 
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Posted: 1/8/2016 12:09:18 AM EDT
[#22]
Sweet, old school tagged.
I wonder if one made entirely out of JB Weld would be strong?
Since it's so viscous, maybe inject the mold with a high volume syringe or two. That's going to be a lot of tubes of the stuff. |
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Posted: 1/8/2016 11:52:04 AM EDT
[#23]
Quote HistoryQuoted:
First, fantastic to see someone else diving into this. Second, can you relate the details of how you went about that mold? From the indentations in the outside pieces, I'm assuming your method has to do with a generous dollop of mold release, which isn't something I've been brave enough to try yet.
Quote HistoryQuoted:
Quoted:
Well I decided do to the shear cool factor of this thread to try my hand at a 3 piece mold. I decided to go with a billet 80% lower I have yet to mess with as the master and bond a fire control pocket from a spikes onto the mold. During the bonding pour I had some leak by that distorted the buffer threads, so I'm going to remove them from the center section and relocate them to the right side mold instead. That being said I poured a lower anyway because...well why not. Turned out ok for a trial run, couple of flaws due to my pocket knife flash removal and clay in the mold I failed to remove. First, fantastic to see someone else diving into this. Second, can you relate the details of how you went about that mold? From the indentations in the outside pieces, I'm assuming your method has to do with a generous dollop of mold release, which isn't something I've been brave enough to try yet.
Thanks! I'm having a blast with the whole thing. I got my kids involved so it's like family craft time.....way cooler than pine cone bird feeders. I made a wooden box then used plastalina clay to layout the parting lines of the next section, poured the first section then brushed some petroleum jelly (just enough so you see a slight sheen) onto the set silicone before pouring the next after flipping it and removing the clay.The index keys were made with the back of a sharpie pressed into the clay. |
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Posted: 1/8/2016 11:55:26 AM EDT
[#24]
The clay I picked was a cheap sulphur free brand from Michael's Crafts.
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Posted: 1/8/2016 12:15:59 PM EDT
[#25]
How did your safety detent channel turn out, or are you planning to drill that?
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Posted: 1/8/2016 1:18:25 PM EDT
[#26]
Quote HistoryQuoted:
How did your safety detent channel turn out, or are you planning to drill that? It's molded about half way through. I'm going to either replace the silicone nipple with a steel one in the mold or use the partial hole as a drill guide. Most likely going with steel pins throughout, as I've been playing with moving things around everything is getting easier to demold. |
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Posted: 1/8/2016 5:29:13 PM EDT
[#27]
This is gold! PURE GOLD!
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Posted: 1/10/2016 8:32:43 AM EDT
[#28]
Quote HistoryQuoted:
Sweet, old school tagged. I wonder if one made entirely out of JB Weld would be strong?
Since it's so viscous, maybe inject the mold with a high volume syringe or two. That's going to be a lot of tubes of the stuff. Would be super brittle and probably shatter if dropped by its self onto concrete. A small hammer and a screwdriver can shatter JB Weld. I love the stuff but probably not a good material for this. I am ordering my supplied for my first attempts today. |
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Posted: 1/12/2016 8:42:47 PM EDT
[#29]
I just bought and am assembling my mold box tonight. Excited to try this out even though I'm late to the party.
I've read the whole thread a couple times, was there ever a concensus on the most viable stuff to cast the lowers in? Should I go ahead and order what Boris used originally, or is there a better alternative? First lowers will be cast without reinforcement, using KNS pins and a GI trigger group. We'll see how that lasts. If it doesn't work very long I'll look into making metal reinforcements ala Boris. Planning on building up a standard lower with modeling clay in strategic areas. Will report success/failure once I get started. |
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Posted: 1/12/2016 10:44:52 PM EDT
[#30]
Quote HistoryQuoted:
I just bought and am assembling my mold box tonight. Excited to try this out even though I'm late to the party. I've read the whole thread a couple times, was there ever a concensus on the most viable stuff to cast the lowers in? Should I go ahead and order what Boris used originally, or is there a better alternative? First lowers will be cast without reinforcement, using KNS pins and a GI trigger group. We'll see how that lasts. If it doesn't work very long I'll look into making metal reinforcements ala Boris. Planning on building up a standard lower with modeling clay in strategic areas. Will report success/failure once I get started. I like the modelling clay idea. Ive pondered that myself with some fiber reinforcement. Im going to try Task 9 for my first couple with reinforcement and some clay to build up the original. How do you guys cut the original from the mold? |
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Posted: 1/12/2016 10:57:07 PM EDT
[#31]
Quote HistoryQuoted:
Do you want to try these? PM me your address and I can send you a bunch. http://i1178.photobucket.com/albums/x368/_ak_74_/fruity_ghost/fg_42.jpg~original How are these made? |
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Posted: 1/13/2016 3:07:42 PM EDT
[#32]
Quote HistoryQuoted:
I've read the whole thread a couple times, was there ever a concensus on the most viable stuff to cast the lowers in? Quote HistoryQuoted:
I've read the whole thread a couple times, was there ever a concensus on the most viable stuff to cast the lowers in? Of the Smooth-On products, Task 9 is probably the best to start with. It will be brittle without some reinforcement, but so will SmoothCast 300, which is far weaker. Quoted:
How do you guys cut the original from the mold? Very carefully.  Boris' early posts in this thread have photographs of some good cut lines. I use a box cutter with a fresh blade for most cuts, and to saw through the full-mold-width cut at the aft end of an inverted receiver, I use a serrated knife. Be ginger as you get close to your receiver, as scratching your anodizing is fairly easy to do with a steel knife.
Much of the success or failure of your castings will be determined by how you cut the mold, so go slowly and carefully, and be sure you have a good mental image of the negative space that will be left behind. Quoted:
Quoted:
Do you want to try these? PM me your address and I can send you a bunch. http://i1178.photobucket.com/albums/x368/_ak_74_/fruity_ghost/fg_42.jpg~original How are these made? Boris made at least two generations of those, one cut as a single piece from sheet steel and bent to shape, and the other with only the hoop bent, the side pieces being welded to the hoop. ETA: I believe Boris has a laser cutter which he used to make those pieces so clean, but since they end up embedded in plastic, the cleanliness of the cuts should not be important, aside from the holes, which could be done precisely with transfer punches and a drill. |
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Posted: 1/13/2016 4:40:43 PM EDT
[#33]
Task 9 it is. Thanks for the feedback.
Once I have a lower cast, I intend to try making a mold to cast the FCG pieces as well, perhaps using the plastic and already reinforced design from an LW-15. Part of me that's very ambitious wants to try casting an upper as well, perhaps based on the extruded DPMS Lo-Pro upper I have. Theoretically, the force of lock-up is taken directly by the barrel extension. Perhaps if one doesn't habitually slam the BCG closed on an empty chamber it might manage to last a few magazines. Posted Via AR15.Com Mobile |
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Posted: 1/13/2016 5:18:09 PM EDT
[#34]
NFA periodically has their plastic lpk on sale. Pics and weights are in the lw parts thread.
Posted Via AR15.Com Mobile |
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Posted: 1/13/2016 8:40:00 PM EDT
[#35]
Thanks.
I think what I really need is a dimension-ally reinforced lower to start with, to use as a pattern. One of the 3D-printed designs would work great, but I don't have access to a 3D printer to make one myself, nor do I know anyone locally that could let me push the button to "make my own". I understand that since the 3D printed lower is a firearm receiver, I can't just have someone mail me one. Ultimately though, I think that would be the best way to start. F3D's success with his 3D-printed pattern reinforced with fiberglass and a castle nut is what I'd like to replicate. Been playing with a stripped lower and modeling clay, and I'm not convinced that my efforts to build it up that way will lead to a satisfactory final product. Maybe I need to convince the wifey that we desperately need a 3D printer, "for art projects!".
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Posted: 1/14/2016 1:38:30 PM EDT
[#36]
Does anyone have any recommendations for a 3D printer under $1000 that's capable of printing receivers and such?
Makerbot Replicator 2 is one I've found with sufficient bed size, and seem to run $800 on the used market. |
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Posted: 1/14/2016 1:45:58 PM EDT
[#37]
Quote HistoryQuoted:
Been playing with a stripped lower and modeling clay, and I'm not convinced that my efforts to build it up that way will lead to a satisfactory final product. True that if you freehanded it all, it would look a bit rustic. I'm wondering if gluing strips of wood to the template receiver and filing in the fillets with clay (or glue) would make for a more professional look to the castings without costing you a 3D printer. (Of course, a 3D printer is a nice thing to have.) Would need to use a non-sulfur glue if working with MoldStar 30. |
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Posted: 1/15/2016 12:58:02 PM EDT
[#38]
Has anyone used a "fruity ghost" lower for a dedicated .22LR build? With a lot less powerful cartridge they should hold up better right?
What about casting an upper? I would assume that it would need to be fiber reinforced like with fiberglass or kevlar or something? Would it be best to make the mold from a commercial plastic upper instead of an aluminum one to take advantage of any dimensional changes they've done to strengthen the upper? I've seen the posts about plastic LPK parts which is cool... but how about plastic parts like an FSB or even a plastic .22LR barrel cast around one of the .22LR liners that are commercially available. I know newer 10/22s use a lot of plastic parts and others over the years have as well back as far as the Remington Nylon 66 from the 1960s. Seems like a .22LR AR could be build that had very few metal parts in it at all. Should be super lightweight. |
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Posted: 1/15/2016 1:07:19 PM EDT
[#39]
Quote HistoryQuoted:
Has anyone used a "fruity ghost" lower for a dedicated .22LR build? With a lot less powerful cartridge they should hold up better right? What about casting an upper? I would assume that it would need to be fiber reinforced like with fiberglass or kevlar or something? Would it be best to make the mold from a commercial plastic upper instead of an aluminum one to take advantage of any dimensional changes they've done to strengthen the upper? I've seen the posts about plastic LPK parts which is cool... but how about plastic parts like an FSB or even a plastic .22LR barrel cast around one of the .22LR liners that are commercially available. I know newer 10/22s use a lot of plastic parts and others over the years have as well back as far as the Remington Nylon 66 from the 1960s. Seems like a .22LR AR could be build that had very few metal parts in it at all. Should be super lightweight. The DPMS Lo-Pro Upper is extruded from 7029 T6 Aluminium, and is already slightly dimensionaly reinforced. It also has a more 'square' shape than a typical upper, with reinforced lines running along it's length at the corners. I'm thinking this would serve as a suitable form for a cast upper. Still looking at 3D printers to buy in order to print a lower. Would absolutely love to see a .22 AR15 made with as many plastic parts as possible. That'd be sweet! |
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Posted: 1/15/2016 5:07:50 PM EDT
[#40]
Quote HistoryQuoted:
The DPMS Lo-Pro Upper is extruded from 7029 T6 Aluminium, and is already slightly dimensionaly reinforced. It also has a more 'square' shape than a typical upper, with reinforced lines running along it's length at the corners. I'm thinking this would serve as a suitable form for a cast upper. Still looking at 3D printers to buy in order to print a lower. Would absolutely love to see a .22 AR15 made with as many plastic parts as possible. That'd be sweet! Quote HistoryQuoted:
Quoted:
Has anyone used a "fruity ghost" lower for a dedicated .22LR build? With a lot less powerful cartridge they should hold up better right? What about casting an upper? I would assume that it would need to be fiber reinforced like with fiberglass or kevlar or something? Would it be best to make the mold from a commercial plastic upper instead of an aluminum one to take advantage of any dimensional changes they've done to strengthen the upper? I've seen the posts about plastic LPK parts which is cool... but how about plastic parts like an FSB or even a plastic .22LR barrel cast around one of the .22LR liners that are commercially available. I know newer 10/22s use a lot of plastic parts and others over the years have as well back as far as the Remington Nylon 66 from the 1960s. Seems like a .22LR AR could be build that had very few metal parts in it at all. Should be super lightweight. The DPMS Lo-Pro Upper is extruded from 7029 T6 Aluminium, and is already slightly dimensionaly reinforced. It also has a more 'square' shape than a typical upper, with reinforced lines running along it's length at the corners. I'm thinking this would serve as a suitable form for a cast upper. Still looking at 3D printers to buy in order to print a lower. Would absolutely love to see a .22 AR15 made with as many plastic parts as possible. That'd be sweet! It is kinda expensive but maybe this upper would be a good pattern... https://www.kaiserus.com/?product=517 This poly upper is much cheaper, but I've heard nothing but bad about this vendor: http://blackthorneproducts.com/cart/index.php?main_page=product_info&products_id=175 |
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Posted: 1/15/2016 5:39:41 PM EDT
[#41]
How hard would it be to cast handguards? They wouldn't need to have heat shields if they were for a .22 I wouldn't think...
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Posted: 1/15/2016 6:07:21 PM EDT
[#42]
Quote HistoryQuoted:
Still looking at 3D printers to buy in order to print a lower. You'll be looking at higher end machines. The ones that made the news were printed don a Stratasys Dimension series if I recall. You'd need a machine that can print with a good dimensional accuracy and has a separate support material. The "built in" supports will cause you plenty of headaches trying to remove then sand down, if it is even possible; I've done prototype parts on machines like that and they are a pain. It got the job done, but the part was more for a visual test and was not intended to actually function. The smallest such machine I am aware (separate support material that melts away with water) of is the Stratasys Mojo, which still has an MSRP of about $5,000 based on the last trade show I was at. But, the MoJo is too small to do a lower. The next one would be the Stratasys uPrint's, which have MSRP's from about $15,000 for the system. The Dimensions are where you start getting the finer layer thickness and more material options. Those start at around $31,000. Additive manufacturing is awesome, but there are some things it just isn't the most practical option for many things. For a lower I could see the benefit of not having to change set-up like you would on a mill, but the geometry itself is nothing you can't do with traditional subtractive methods. For less cost than a good AM machine, you could get a small CNC mill, tools, and a lot of plastic blocks. |
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Posted: 1/15/2016 6:31:40 PM EDT
[#43]
Quote HistoryQuoted: How hard would it be to cast handguards? They wouldn't need to have heat shields if they were for a .22 I wouldn't think... Be easier to build them out of Legos...
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Posted: 1/15/2016 6:34:03 PM EDT
[#44]
Quote HistoryQuoted:
You'll be looking at higher end machines. The ones that made the news were printed don a Stratasys Dimension series if I recall. You'd need a machine that can print with a good dimensional accuracy and has a separate support material. The "built in" supports will cause you plenty of headaches trying to remove then sand down, if it is even possible; I've done prototype parts on machines like that and they are a pain. It got the job done, but the part was more for a visual test and was not intended to actually function. The smallest such machine I am aware (separate support material that melts away with water) of is the Stratasys Mojo, which still has an MSRP of about $5,000 based on the last trade show I was at. But, the MoJo is too small to do a lower. The next one would be the Stratasys uPrint's, which have MSRP's from about $15,000 for the system. The Dimensions are where you start getting the finer layer thickness and more material options. Those start at around $31,000. Additive manufacturing is awesome, but there are some things it just isn't the most practical option for many things. For a lower I could see the benefit of not having to change set-up like you would on a mill, but the geometry itself is nothing you can't do with traditional subtractive methods. For less cost than a good AM machine, you could get a small CNC mill, tools, and a lot of plastic blocks. Quote HistoryQuoted:
Quoted: Still looking at 3D printers to buy in order to print a lower. You'll be looking at higher end machines. The ones that made the news were printed don a Stratasys Dimension series if I recall. You'd need a machine that can print with a good dimensional accuracy and has a separate support material. The "built in" supports will cause you plenty of headaches trying to remove then sand down, if it is even possible; I've done prototype parts on machines like that and they are a pain. It got the job done, but the part was more for a visual test and was not intended to actually function. The smallest such machine I am aware (separate support material that melts away with water) of is the Stratasys Mojo, which still has an MSRP of about $5,000 based on the last trade show I was at. But, the MoJo is too small to do a lower. The next one would be the Stratasys uPrint's, which have MSRP's from about $15,000 for the system. The Dimensions are where you start getting the finer layer thickness and more material options. Those start at around $31,000. Additive manufacturing is awesome, but there are some things it just isn't the most practical option for many things. For a lower I could see the benefit of not having to change set-up like you would on a mill, but the geometry itself is nothing you can't do with traditional subtractive methods. For less cost than a good AM machine, you could get a small CNC mill, tools, and a lot of plastic blocks. Uh, the technology has moved on quite a bit from Defense Distributed. No need for a $15 K machine to print a lower. Should be a few hundred. Look up WarFairy's Charon, which is an entire generation old @ least. |
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Posted: 1/15/2016 6:59:38 PM EDT
[#45]
Quote HistoryQuoted:
Uh, the technology has moved on quite a bit from Defense Distributed. No need for a $15 K machine to print a lower. Should be a few hundred. Look up WarFairy's Charon, which is an entire generation old @ least. Quote HistoryQuoted:
Quoted:
Quoted: Still looking at 3D printers to buy in order to print a lower. You'll be looking at higher end machines. The ones that made the news were printed don a Stratasys Dimension series if I recall. You'd need a machine that can print with a good dimensional accuracy and has a separate support material. The "built in" supports will cause you plenty of headaches trying to remove then sand down, if it is even possible; I've done prototype parts on machines like that and they are a pain. It got the job done, but the part was more for a visual test and was not intended to actually function. The smallest such machine I am aware (separate support material that melts away with water) of is the Stratasys Mojo, which still has an MSRP of about $5,000 based on the last trade show I was at. But, the MoJo is too small to do a lower. The next one would be the Stratasys uPrint's, which have MSRP's from about $15,000 for the system. The Dimensions are where you start getting the finer layer thickness and more material options. Those start at around $31,000. Additive manufacturing is awesome, but there are some things it just isn't the most practical option for many things. For a lower I could see the benefit of not having to change set-up like you would on a mill, but the geometry itself is nothing you can't do with traditional subtractive methods. For less cost than a good AM machine, you could get a small CNC mill, tools, and a lot of plastic blocks. Uh, the technology has moved on quite a bit from Defense Distributed. No need for a $15 K machine to print a lower. Should be a few hundred. Look up WarFairy's Charon, which is an entire generation old @ least. Not really, no. The additive processes haven't moved too much overall. Consumer level machines have gotten better, sure, but they still don't compare to the professional models. I probably should have clarified that I was considering a completely standard forged lower that would be ready to accept an LPK and shoot no problem. The newer designed specifically made to be created on an FDM (or generic equivalent) machine, or even a standard design, can be made on a household machine, but I wouldn't expect it to last long or trust it much. The higher end machines allow for a lot more modification to way the STL is generated and can produce much more robust components. Heated build chambers are beautiful things. If I recall, the original WarFairy build was done on a LulzBot and it had issues from the get go with holes needing to be opened, durability of select areas, thread problems, straightness problems, and didn't last too long before cracking. Alternatively, I wouldn't want to use a photopolymer based process (SLA, DLP, DMD, etc) because their materials are not as durable. Certainly not the powder-binder processes either. SLS would work, but those machines are massively expensive. Basically, I can print out a lower on the $700 machine I have access to, but compared to the same lower printed out on a $15000 machine, the difference would be significant in durability and post processing requirements. |
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Posted: 1/15/2016 7:06:10 PM EDT
[#46]
Quote HistoryQuoted:
Not really, no. The additive processes haven't moved too much overall. Consumer level machines have gotten better, sure, but they still don't compare to the professional models. I probably should have clarified that I was considering a completely standard forged lower that would be ready to accept an LPK and shoot no problem. The newer designed specifically made to be created on an FDM (or generic equivalent) machine, or even a standard design, can be made on a household machine, but I wouldn't expect it to last long or trust it much. The higher end machines allow for a lot more modification to way the STL is generated and can produce much more robust components. Heated build chambers are beautiful things. If I recall, the original WarFairy build was done on a LulzBot and it had issues from the get go with holes needing to be opened, durability of select areas, thread problems, straightness problems, and didn't last too long before cracking. Alternatively, I wouldn't want to use a photopolymer based process (SLA, DLP, DMD, etc) because their materials are not as durable. Certainly not the powder-binder processes either. SLS would work, but those machines are massively expensive. Basically, I can print out a lower on the $700 machine I have access to, but compared to the same lower printed out on a $15000 machine, the difference would be significant in durability and post processing requirements. Quote HistoryQuoted:
Quoted: Uh, the technology has moved on quite a bit from Defense Distributed. No need for a $15 K machine to print a lower. Should be a few hundred. Look up WarFairy's Charon, which is an entire generation old @ least. Not really, no. The additive processes haven't moved too much overall. Consumer level machines have gotten better, sure, but they still don't compare to the professional models. I probably should have clarified that I was considering a completely standard forged lower that would be ready to accept an LPK and shoot no problem. The newer designed specifically made to be created on an FDM (or generic equivalent) machine, or even a standard design, can be made on a household machine, but I wouldn't expect it to last long or trust it much. The higher end machines allow for a lot more modification to way the STL is generated and can produce much more robust components. Heated build chambers are beautiful things. If I recall, the original WarFairy build was done on a LulzBot and it had issues from the get go with holes needing to be opened, durability of select areas, thread problems, straightness problems, and didn't last too long before cracking. Alternatively, I wouldn't want to use a photopolymer based process (SLA, DLP, DMD, etc) because their materials are not as durable. Certainly not the powder-binder processes either. SLS would work, but those machines are massively expensive. Basically, I can print out a lower on the $700 machine I have access to, but compared to the same lower printed out on a $15000 machine, the difference would be significant in durability and post processing requirements. We're talking past each other. I wasn't referring to the technology of 3-D printers - the cost is slowly coming down, but consumer level machines use a pretty large drop compared to expensive ones - I was referring to the technology of the printed lower. WarFairy's Charon was a CavArms type integrated lower, which greatly reinforced the buffer tube region - and was printed in 4 parts, allowing it to be printed on rather small printers. The latest printed lowers have a significantly reinforced buffer tube boss. |
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Posted: 1/15/2016 7:29:50 PM EDT
[#47]
Zman, thanks for your input. I just want to make sure we're all on the same page:
I'm not necessarily wanted to print an AR15 lower and use it as a firearm part. I'm simply wanting a dimensionally reinforced lower that I can use as a form for casting using Boris' and F3D's processes. Printing one myself seems to be the most expedient way to acquire one, since no one is selling 3D printed lowers that I've found. The 3D printed designs have been reinforced substantially so that they will last at least short-term. I think that using the same reinforced design, only cast out of Task 9 or Smoothcast 300 (which are apparently considerably stronger than a 3D printed product) would be wonderfully suited for long-term use. Obviously it's not going to be something I'd throw in my trunk as a defensive weapon, but as a range toy and a substantial 'fuck-you' to the .gov and ATF, I think it'd be amazing. Right now I only have access to standard lowers, and even if I bought an expensive billet lower with integrated trigger guard, it's still not going to be dimensionally reinforced around the buffer tower or the take-down pins, like the 3D printed designs are. I could build up a standard lower with modeling clay and install an arched trigger guard, but I'm afraid the end product won't be near as 'neat' looking as a 3D printed lower. I agree that consumer-grade 3D printers, at least the one I've seen and had limited personal dealings with (owner no longer has it, or I'd ask him to let me print one on it) are not yet capable of producing parts with enough strength to hold up as a lower in a 5.56 rifle for very long. The one 10-round magazine that I have printed is more or less a display piece, since I feel like it would crack if I actually left it loaded or tried to use it. It's pretty cool though! Once again, I'm asking which of the consumer grade 3D printers would be capable of printing a nice looking AR15 lower to use as a form. Does anybody have any recommendations? |
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Posted: 1/15/2016 7:36:33 PM EDT
[#48]
Quote HistoryQuoted:
It is kinda expensive but maybe this upper would be a good pattern... https://www.kaiserus.com/?product=517 This poly upper is much cheaper, but I've heard nothing but bad about this vendor: http://blackthorneproducts.com/cart/index.php?main_page=product_info&products_id=175 That first upper might work. I'm still thinking of trying it with my DPMS upper first, since it's what I have. Looking at the Poly Lower on the first link, it doesn't seem to be reinforced around the buffer tower like I'm looking for. Most of the 3D printed designs have made that area square, and the walls for the FCG are much thicker, which would probably prevent holes from wearing out. |
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Posted: 1/15/2016 7:37:41 PM EDT
[#49]
Quote HistoryQuoted:
Be easier to build them out of Legos... Quote HistoryQuoted:
Quoted: How hard would it be to cast handguards? They wouldn't need to have heat shields if they were for a .22 I wouldn't think... Be easier to build them out of Legos... No legos... I was just wanting a light weight set of basic M4 looking handguards molded in the same color plastic as the "fruity ghost" receiver... The point would be to try to mold as many parts in plastic as possible... plastic barrel around one of those .22LR liners, plastic FSB, A2 flash suppressor, pistol grip, as much of the LPK as possible, etc... My only concern with the handguards is they are fairly thin, but so is the sides of a lower, so I'd guess it would work O.K. |
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Posted: 1/17/2016 2:09:45 AM EDT
[#50]
I bet it would work. If you look at the inside of most plastic handguards, they've got reinforcing ribs and such.
Something you could even do would be the leave the heatshields in, and perhaps fill the space between the heatshield and the handguard with clay. This would thicken the handguards in your final product. With a .22 you shouldn't need the heatshields anyway. |
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