Ok, you can quit laughing now.  You wanted to read this thread even though an Aggie started it.

Can a working AR lower be built from Legos?  It would have to be glued, & probably the empty spaces in the bricks filled w/ epoxy.  A thumbhole stock would help reinforce the all important buffer attach point; sadly Bell & Carlson no longer make their thumbhole stock, & I've been unable to find anyone who sells Remington's.

My initial thought was to create a plastic adapter between an AR upper & an FAL lower, but it ends up looking like a California AR & the buffer tube attach point is still weak.

Before you say it can't be done, or post a silly smiley face, it's already been done out of wood.  So start thinking HOW it can be done, & the best glues & how to solve the buffer tube attachment problem.

Farmers Fight!

backbencher

Can it be done? Probably.

Should it? Probably not.

The real question you need to ask yourself is Why?. It won't ever be economical or desirable to do, so about the only reason you should do this type of thing is just for novelty purposes. If that's enough for you, then go for it.

can't imagine epoxy and legos could take the recoil.  it would break like that ati lower.

Why?  B/c not everyone has a mill @ home to build an 80% lower.

B/c 80% lowers are expensive & hard to find.

B/c Legos & epoxy are easy to buy @ Wal-Mart.

B/c it would provide an entree into home gunmaking for thousands who wouldn't otherwise build an AR.

B/c it would provide a starting point for other firearms projects.

Let's flip that question around - WHY should it NOT be done?

It's not a good idea to have your FCG and upper mounted to plastic toys. Too many moving parts. Plus, how do you propose to accurately attach the receiver extension as well as threading said structure. Also, need to bare and mill openings for detente and springs.

1 - Plastic lowers are already in use.  A solid structure built of Legos filled w/ epoxy & solidly glued together may be strong enough for the lower calibers.  I'm not proposing a donor receiver for a .50" BMG or .458" SOCOM upper.

2 - Moving parts - trigger, hammer, safety, buffer?  That's too many moving parts?

3 - The buffer tube is the bugbear.  Hence my sudden interest in AR thumbhole stocks - they've already got the buffer tube aligned, thus there's no need to thread the lower - just glue in place.

4 - For the trigger, my initial thought is to use a drop in all in one trigger assembly.  Expensive, but no need to drill accurately through the side of the receiver.  It can be glued in place.  The safety will be an issue - may have to drill - but may be able to position a block w/ an existing hole in the right spot.  If it's too big, an expansion ring can be attached.

My thought is not to worry about a mag well on the initial go.  The receiver pins can be replaced by screws, as can the buffer retaining pin assembly, no bolt hold open, and no magazine release.

It's just a remarkably stupid idea.  Why would you use hundreds of expensive plastic squares?  You like Legos.  I get it.  My 7 year old son likes them too.    However, there are far better materials available.  

I think I read about someone using plastic butcher block?    

Or use hardwood.  

Or anything porous, soaked in fiberglass resin.

Screw the naysayers. Go for it. Post build, finished and firing pictures and video for us all to enjoy.

Ever step on a Lego in your bare feet?  Those little motherf*ckers already are anti-personnel weapons.

Sounds like a good way to get a BCG to the face.  

What about a Lego quad rail!

Do it!

No, haven't played w/ Legos for 27+ years.  If you've got a better idea on how to create, w/ out many tools, an AR lower, let's hear it.  Pine's been tried, & failed, after 3 shots - the bolt jammed in the buffer tube when the weak mount failed.  The same chap went on to make a working plastic lower from 3 sheets of plastic he bonded together.  However, both experiments were preparations for him milling an 80% aluminum lower - the man has a complete workshop set up, w/ a mill.

Shall we use a cardboard lower, soaked in fiberglass resin?  Somehow that seems a bit brittle, but I'm game to try.  It would allow us to make it one piece with the stock - which would ease our worries about the buffer tube mounting.  What would we do?  Build a cardboard mockup of an AR lower & soak it in resin?  Never worked w/ fiberglass, so expound for us.

What about using the plastic they use ar vise blocks? I don't think Legos would hold up very well. If you epoxied every bit of the Lego maybe, I say go for it though. It would be interesting, and shit Legos are pretty cheap!!!

If you google some of the other stuff built from legos you wouldnt be so quick to dismiss his idea.  I cant beleive someone hasnt already done this honestly.  Its not going to be practical.  If AR's were banned or simply could no longer be trannsfered, but for some reason a loophole existed alowing for a private build it wouldnt be so laughable.   I say go for it.  As long as its just for the sake of trying it and not something you actually plan to fire more than to prove...   There is a thread going rite now about an ATI lower breaking on the second shot...  

Im looking forward to someone making a real carbon fiber lower.  Not a carbon15 or whatever but a true hand laid carbon upper and lower.  Im a race car tech and see all kinds of exotic uses of carbon fiber.  It would cost a fortune but it would be super lite... Id guess even a BC could be made of carbon.  Truely exotic carbon can blend steel or aluminum for high heat or wear surfaces.   Obviously this would not be intended for mass market as the price would be too high for most.  But some out there would pay quite a bit of money for a reliable ar pattern gun that weighed half of a current lightweight model.

I think it would be a cool project.

Do it!

No reason to not do it...it will be fun!

Legos are the shit!

Bret

I built a camera out of legos once upon a time and used rubber cement to hold it together (it was for a semi-permanent display)

I was able to disassemble it, mostly, so I would not recommend using rubber cement

I imagine you could make a fairly sturdy thing out of Technic.  I haven't been keeping up to date with legos for quite a while but I know they have all kinds of crazy pieces now

Look at 3m panel bonding epoxy. We glue 1/4 panels on cars with it at work. Pretty tough stuff. You would probably have to use some adhesion promoter on it to.

What is adhesion promoter?  I was thinking we'd rough 'em up a bit before we glued 'em, so the glue would stick better.  The underside will also be filled w/ whatever glue we're using, or some sort of expoy.

There's 1604 different bricks available @ shop.lego.com on 161 pages, so if some of you have some time, go take a look & find some likely pieces - and note which page they're on.  Or if your kids have 'em, play w/ 'em - and take pics AS YOU'RE BUILDING IT.

Assumptions:

1 - No magazine well 1st time out - this will be a single shot for now.  It's Legos - we can build a new upper easily once we know it holds together.
2 - We will have a thumbhole stock.  Preferably a Remington, but an old Bell & Carlson if we can find one.  Or some other current maker.  This is to align & reinforce the buffer tube mounting point.
3 - Would like to go w/ a drop-in trigger, but not seeing any below $150, so will probably have to use standard AR semi-auto parts.  That means drilling or positioning Legos w/ holes in exactly the right spot.
4 - Upper will not be pinned in - will use ordinary bolts & nuts, reinforced w/ washers.  This isn't a combat weapon that has to be easy opening to clear jams.
5 - No bolt hold open.
6 - Buffer will be held in w/ a screw, not a spring & pin.
7 - This will ultimately be set up under the GPL or something similar, for free use by anyone.  I'm not trying to make any money on this - just to show that anyone can build an AR @ home, & have a fun range toy they built themselves.

I have a better idea, just go buy a cheap 3d printer. It'll be as structurally sound as the Legos and epoxy... And the cad files can be found for download. If you want to try the Legos for the novelty of it I say go for it... But it's a terrible idea for real use.

i know this would be just a toy but kinda cool to build. here is a guy that built one

Outstanding idea!  Post a link to a 3D printer cheaper than a bunch of Legos & expoy, and I'll buy one.

If you actually build this, please be sure to video the test shots and post the video of the BCG going through your eye on here after you are released from the hospital. Thank you.

and I thought I was being a little harsh.  Sheesh...

Just messing.

Worst will happen is the lower comes to pieces & the BCG gets stuck in the buffer tube, which would be a lot worse than what happened to the wooden lower that was missing the front pin ears.  W/ that much expoxy, it may be heavier than the original, & I don't think it'll come apart unless someone drops a .458" SOCOM upper on it.

Eugene Stoner's childhood home movies?



 

probably would have been made from lincoln logs.

I dunno, Legos have been around since the late 40s.



 

I think the main issue is that when most people build things out of Lego, they are models.  The dimensions can be altered to fit the Lego block module. But in this case you need to make it to pretty exact dimensions.  English dimensions, not metric.  So you are going to have a hell of a time getting any of the non-Lego parts to fit.

Bang on point.  Two advantages - the rear receiver doesn't have to be exact other than the buffer tube, and we're not doing a magwell right now.  If we get spendy & use an enclosed trigger group, we can glue that in place.  We only have to align the upper, buffer tube, safety, & hammer on the 1st attempt.  And we can drill the little buggers, just want to do as little as possible.

Confirmed Legos & K'nex work together tonight.  Probably well known, but wanted to see for myself.

Seeing your FAL thread, why don't you try working out something that could be potentially feasible?

AR upper and Sig 556 lower... and go.

If price is your real issue, try just making one out of epoxy first? Make a clay mould of a lower and fill it. It still won't really be safe, but way easier than Legos. Heck, you could even dump random 1x1 Legos in as you go and weaken the overall structure for the sake of Legos!

Before you settle on epoxy, consider that it works best on objects that are porous or very rough.  Give ABS cement (plumbing section) a try and see if that will weld your LEGO pieces together.  Similar to PVC cement but not quite the same so make sure you get the correct one.

I can't believe Im replying to this stupid thread, but legos are mostly abs, and that takes acrylic glue, not found in big box stores. You can get it from amazon for 4 bucks a can.

Well done, Taylor, you're the only other one in this thread that knew Legos were ABS plastic.  That makes you a Lego SME by our standards, so we'll have more questions for you later : )

The downside to the SiG 556 lower is cost - $300 on up - that buys a lot of Legos.  Have a question on another forum about Beretta AR-70 lower blueprints; if I can't find any, I'll just buy a lower from Numrich IOT measure it.

I think we are a long way away from actually gluing parts together - we need a suitable thumbhole stock first, and I have seen one on an Anderson Rifle AR for sale in New Zealand - I've emailed to find out where it can be gotten from.  If we can't find a thumbhole stock in production, that seriously complicates the design, as we have to precisely locate the buffer tube - and reinforce it, both of which a thumbhole stock would do for us.

If we designed a stock we could use, does anyone know of a stock maker that would make it for a reasonable price?  Having the lower securely glued to a solid wood thumbhole stock would greatly reinforce it, as well as precisely locate the buffer tube - and transfer the stress of the buffer tube mounting point to the stock.

If all goes well, in a few weeks I'll put in an order for a childhood orgy's dream of Legos, and I can begin roughing out a lower.  Feel free to dive into your kids' collections & post the results here.

I'm not 100% certain I see your intent - but if you're looking to make a cheap AR lower with minimal tools out of common, easy to find parts - I would think something similar to this:



http://www.assaultweb.net/forums/showthread.php?t=133335

...would be both easier to do, and more functional.

A couple of thoughts:

While I get the idea of making a "first draft" as a proof of concept - if you're not going to use a magwell, why bother with an AR upper anyways?  If you're building a single shot gun with non-serialized components, there are other designs that would be easier to build using limited parts that are not as complex as a semi-auto design.

Also - consider this - if lower receivers/serialized components can't be secured - what guarantee is there that any components or ammunition would continue to be available?  

If you're stockpiling ammunition and/or reloading components already - chances are you already own guns.  If they cut the supply off in a hypothetical future, why would they cut off lowers only?  If you can't own the lower/it gets confiscated, why would they sell the non-serialized parts, too?

Anyways, not trying to discourage you, and I'm interested to see what you come up with for the novelty at least.

~Augee

I'd like to see this brainchild work out!

Apparently there are plenty of places that make custom lego pieces.

Now you have to do this.

-T

The plumbing section of big box stores, even your local Ace Hardware, will obviously have (in addition to copper) PVC pipe (and its cement) that is used for DWV (drain, waste, vent).  They ALSO have plastic supply line which is ABS (the same plastic as LEGO, which is why I recommended it); it is sized differently and has a separate cement from PVC.  This cement should chemically weld LEGOs together.  Maybe it's the same as your acrylic glue - don't know.  But it is local and no shipping charges.

The thread is only stupid in the sense that is silly.  REALLY SILLY.  What fun!

Best of luck with your stock.  If you do end up with wood, very rough surfaces and lots of epoxy may be your only hope.  Precision milling and metal backing plates if you hope to bolt it in place. I'm sure you would bore the stock and insert a standard buffer tube, right?  Keep us posted on your progress!

Augee, "... if you're looking to make a cheap AR lower with minimal tools out of common, easy to find parts - I would think something similar to this...would be both easier to do, and more functional."

I'm going to disagree here, & quote from KT Ordnance's website(http://www.ktordnance.com/kto/products.php):  "In order to complete this frame: Drill selector hole, drill fire control holes (2 req.), mill out fire-control area."  2nd, they want $250 for their clever idea, and they don't take credit cards.  It might be easier if you have a mill, but then you could use any old 80% lower.  Even the multipart flat lower in your link requires much drilling.

We could start simpler - build a Lego lower for a Ruger Mk II or III, but I'm not sure what we would have achieved there.  We could spend a great deal of time carefully engineering a magazine well for our Lego AR, all to have it fall to pieces on our 1st shot.  What I'm proposing is to create a single shot lower that uses an available thumbhole stock; if it works, we can engineer the mag well later.  If we succeed w/ a single shot, the interest garnered will make the mag well easy.

tutone, thanks for the research.  That Breceo looks particularly interesting - metal Lego compatible parts.  That would certainly make the gadget a bit stronger.

I propose to call this design of small building blocks - the Feinstein.  It's time the good name of Feinstein was redeemed.

Farmers Fight!

backbencher

Do it the "antis" would have a cow. It has been done out of wood. Legos and a .22 upper for the win

I was thinking 7.62x39 w/ AK mags for the win, but if we can get it to work, we have an infinitely variable length AR lower on hand, and you can build mags for whatever caliber you wish out of Legos...

This is crowdsourcing design, folks.  If you're reading, I need volunteers to A) find us an in production thumbhole AR stock like this:

http://www.outdoorsupplies.co.nz/Anderson_AM15.html

or B) design, build, & send off to http://www.gunstockduplicating.com/ a thumbhole AR stock to get a price quote for single duplicates.

or C) acquire a thumbhole stock as above, or the Bell & Carlson/Remington, send off to the folks above, or a similar outfit, & get a price quote for single duplicates.

or D) build a plastic building block thumbhole stock w/ the following features:
- 1 - it will remove from a conventional AR lower w/o damaging the safety spring.
- 2 - a carbine length (milspec or commercial) buffer tube is fully supported on at least 180 degrees of the radius, and the locking lug strip is fully enclosed on at least two sides.  (side & bottom, or both sides)
- 3 - a full length buffer tube is fully supported on @ least 180 degrees of the radius, excepting that portion which overlaps the carbine length locking lug strip space, and the rear of the buffer tube rests on the inside rear of the stock.
- 4 - both buffer tubes types MUST be accommodated, ie, the stock design must fit both types of buffer tubes, & both sizes of carbine tubes.
- 5 - the front of the stock as nearly possible enclose the rear of the AR lower, and as much as possible, supports that structure.
- 6 - the method of building shall be buttons or bottoms are exposed on the butt of the stock; the top, sides, & bottom of the stock shall only display seams between bricks.
- 7 - the stock shall have at least two different manufacturers of bricks in the structure (Lego, K'nex, etc), and the building picture instructions will clearly indicate the different manufacturer blocks used.
- 8- if behind enemy lines in California, New York, etc, the thumbhole requirement is dropped.
- 9 - it shall be accompanied by CLEAR pictorial instructions, with special attention paid to # 7, above.
- 10 - it shall be shot for a 5 round group, glued or unglued, with video, load data, and pictures of measured group.

This will end up under the GPL, or similar, so don't expect to make any money off this - but you will introduce a lot of new folks to shooting.  Please specify which project you are volunteering to work on.  Time to put your money where your mouth is, gentlemen.

Sorry - I wasn't saying that you should use that kit - but just the concept of metal flats bolted together.  

It might not be the most ergonomic and most durable design, but a combination of hand cut wood - possibly in conjunction with the thumbhole stock, and flats drilled with a hand drill and bolted together - I'd think it would achieve the same goal, and at least be functional.  

You could use wood and screw the pistol grip/thumbhole stock to a "grip frame," while using a "drop in" trigger module (pre-aligned) and securing it between two metal flats, and maybe using something to fashion a "floor" for the receiver.  All you'd need to do is drill the holes for the receiver pins.  You'd have no buffer detent, saefty, or bolt release - but it would meet the intent of a functional firearm using only basic parts from a hardware store and non-serialized parts, and using only hand tools.  

~Augee

For the sake of minimum configuration for simplicity, you don't need a safety.  As a single shot that will only be test fired for function (once?), use loading and unloading as the safety.

You will need a friend willing accomplice to help you load the rifle since loading an AR is always a three handed operation.  Usually the magazine or bolt catch is the third hand.  You won't have either.
You could toss a round in the air with the proper rotation so that you could pull the charging handle back and deftly catch in the upper and release the handle while holding the rifle pointed in a safe direction.
That will take some practice.

To reply to each comment in turn:

Augee, in the thread you cite is a bolted together flats kit, w/ no milling required.  Even if we only have to drill the receiver pin holes & the safety, that's 6 holes to drill through metal.  A lot of folks don't have the equipment to do so.  If we build a lower out of building blocks, you'll be able to mail the upper for your hunting trip, and assemble your lower in your hotel room.  If we get lucky w/ dimensions & design, we might not have to drill anything on this lower - there are building blocks that come w/ holes pre-drilled.  At worst, we'll be drilling through plastic - and if we mess up, we can throw away that 10 cent piece & try again.  Besides, the idea of building a functional AR out of plastic building blocks seems to appeal to the popular imagination.

Patman, I disagree.  We will fire the single-shot AR lower several times for function testing and accuracy, before moving on to a magazine fed lower.  All of the rear design will be complete before we add the magazine well.  A safety (not necessarily an AR safety) must be installed.  You bring up a good point about loading - our test firers must be accomplished jugglers or knuckle draggers.  I'm confident I can place the stock on my chest, hold the charging handle to the rear w/ my left hand, & charge the rifle through the ejection port with my right.

Who is volunteering to build a thumbhole stock?  I will build one, but it is very unlikely I will have a chance to test fire it any time in the near future, unless I find an armorer that is as crazy as I am.  A glued thumbhole stock on a standard AR lower should produce little risk to the firer, and in the case of Californians & New Yorkers, can provide a positive benefit as y'all can produce a glued non-thumbhole stock that will satisfy your state laws & horrify the legislators who wrote them.

What are we waiting for, gentlemen?  Someone to hand you a completely finished stock & a box of ammo?  Put your name down in the annals of history as a completely insane person, a committed rifleman (or a rifleman who should be committed), and a patriotic American.  Just tell me you're working on A, B, C, or D.

Farmers Fight!

backbencher

From CRS:

"We are able to duplicate the stock; we can get the hole through the pistol grip but have no means to drill the hole for the recoil spring. Please contact us if you have any further questions.
Thanks
Jesse & Cindy
C.R.S.
Custom Rifle Stocks
814-349-2403"

If we were to use a wooden thumbhole stock, I would suggest inletting the top or side for the buffer tube - something that might also work for a building block stock.

Beat me to it...  Wasn't JPFO going to sell these and the ATF had the proverbial cow...  

BTW, based on the cost of Lego, it would be cheaper to buy an AR15 off the shelf.  Also, many other countries realize receivers are pretty easy to make at home.  They regulate the barrels, trying making a top quality rifled barrel in your garage.