Testing engraving on my Ghost Gunner - Page 1

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[ARCHIVED THREAD] - Testing engraving on my Ghost Gunner

Posted: 9/22/2018 11:30:45 PM EDT

Attempted a test engraving for 601 markings on a scrap lower today. Going to have to set a deeper cut since the Z axis isn't perfectly level. a large portion of the design didn't touch the metal with the bit, and the parts that did cut are so shallow they look laser engraved. Looking at my gcode, I think I added a zero to my target depth accidentally (used a target depth of .0025 instead of .025). Will attempt another cut on the same scrap lower tomorrow, after I edit my gcode.

Posted: 9/22/2018 11:45:07 PM EDT

[#1]

Hi. I have a GG2 with spindle mod and a whole lot of scrap lowers. I'd like to learn more about how to engrave. I know there's a program some people have bought but I didn't think it could do more sophisticated carving. I need to find out more

Posted: 9/22/2018 11:48:12 PM EDT

[#2]

You should shim the Z to get it level because if you just use a deeper DOC it will look funny. Ask me how I know.

Posted: 9/23/2018 12:18:39 AM EDT

[#3]

Quote History

Quoted:
Hi. I have a GG2 with spindle mod and a whole lot of scrap lowers. I'd like to learn more about how to engrave. I know there's a program some people have bought but I didn't think it could do more sophisticated carving. I need to find out more

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Quoted:
Hi. I have a GG2 with spindle mod and a whole lot of scrap lowers. I'd like to learn more about how to engrave. I know there's a program some people have bought but I didn't think it could do more sophisticated carving. I need to find out more

There was a company that was charging a lot of money to turn text and images into code for people, that may have been what you heard about. There is also an online tool that will generate code out of images and lines of text ( https://ghostwriter.serverrack.net/ ).

I'm using Inkscape to create vector graphics and then using CamBam to generate gcode that I run in Universal Gcode Sender instead of DDCut. I have a tutorial that I got online in a Word document that I could send you. If you want it, PM me your e-mail address.

Quoted:
You should shim the Z to get it level because if you just use a deeper DOC it will look funny. Ask me how I know.

I don't know how to go about trying to shim the Z on a Ghost Gunner, the work surface is parallel to the Z, not perpendicular. The table is square, but the area where I'm engraving isn't supported by the jig very well (sticking up in the air above the table). I think I'm only out of square by a couple of thousandths. I'm going to try again on the same scrap with the depth of cut doubled tomorrow - it was way too shallow today even if Z was level.

Posted: 9/23/2018 8:16:22 AM EDT

[#4]

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Quoted:

I don't know how to go about trying to shim the Z on a Ghost Gunner, the work surface is parallel to the Z, not perpendicular. The table is square, but the area where I'm engraving isn't supported by the jig very well (sticking up in the air above the table). I think I'm only out of square by a couple of thousandths. I'm going to try again on the same scrap with the depth of cut doubled tomorrow - it was way too shallow today even if Z was level.

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Oooh. I understand. I have a Tormach, so it is a more traditional setup. I guess if you are able to get it just right, it will look like a roll mark, since those aren’t always uniform. Looking forward to seeing your next effort. The graphic looks tantalizingly good.

Posted: 9/23/2018 3:06:01 PM EDT

[#5]

Tried again with the depth doubled to .005". That did almost nothing. Bumped it up to .02". Way too deep. I'll have to start with another scrap lower tomorrow. Going to try .01" depth. Horsey turned out warped - I think the bit was moving the surface as it was cutting, due to inadequate support. Hopefully a shallower cut will fix this.

This is the .02" result (keep in mind, it is the third pass for some of the lettering to the right):

Posted: 9/23/2018 7:07:40 PM EDT

[#6]

LOL

Posted: 9/23/2018 7:35:07 PM EDT

[#7]

This is why you iron out the kinks on scrap lowers. A depth of .01" with a finer bit (planning to use a 15 degree point, .3mm tip) should give the results I want.

Posted: 9/23/2018 9:07:06 PM EDT

[#8]

Have you considered doing your testing on EP Armory plastic 80%? They're really cheap.

Posted: 9/23/2018 9:14:21 PM EDT

[#9]

Does appear to be some shifting, chattering and some smearing of the aluminum. Are you keeping coolant or light oil on the part as it's being cut and do you have everything absolutely clamped solid? Keep the bit as far into the collet as possible and slow the feed down some.

Posted: 9/23/2018 10:18:03 PM EDT

[#10]

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Quoted:
Have you considered doing your testing on EP Armory plastic 80%? They're really cheap.

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Quoted:
Have you considered doing your testing on EP Armory plastic 80%? They're really cheap.

I prefer working out the bugs in the actual material that will be used for the end product, no surprises that way. I have several scrap lowers to use for this (most of which come from the Ghost Gunner cutting oversized selector holes before I went back to using a drill press and a jig for the holes).

Quoted:
Does appear to be some shifting, chattering and some smearing of the aluminum. Are you keeping coolant or light oil on the part as it's being cut and do you have everything absolutely clamped solid? Keep the bit as far into the collet as possible and slow the feed down some.

The Ghost Gunner is made to run dry, even when cutting a fire control pocket - so no coolant. There's no way to clamp solid, the lower is standing vertically in a plastic jig with the Z axis coming in from the side, not from above like every setup I've ever used before (I used to use a CNC router to build guitars and I've done some really intricate inlay with delicate material and tiny, fragile bits). All my adjustments are going to have to come from bit selection, depth of cut, and feed rate.

The last mangled attempt was with a 30 degree cutter running too deep. I'm certain it was pushing the lower out of square as it was cutting, and the bit was too wide. The first attempt, which was much cleaner, was a much shallower cut using a tiny broken shell cutter (used to cut mother-of-pearl for inlay). The fluted portion was broken off, but it still had a sharp,pointed tip, and was running .0025" deep. I ordered a bit today that should give similar results - a 15 degree conical .3mm tip. I'm going to need to adjust for several very shallow passes, basically scratching away the aluminum like I do with shell, in order to avoid putting enough pressure on the lower to cause any flexing.

Once I get all my trial-and-error out of the way, I can do some pretty precise work. this is one of my inlays (abalone in mango):

Posted: 9/23/2018 10:52:08 PM EDT

[#11]

How about feeds and speeds? When I engrave amuminum, I use a 1/16” ball end mill at 7 IPM and 10,000 RPM. I’d run even higher RPM except that’s all the fast my mill will go.

Posted: 9/23/2018 11:16:50 PM EDT

[#12]

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Quoted:
How about feeds and speeds? When I engrave amuminum, I use a 1/16” ball end mill at 7 IPM and 10,000 RPM. I’d run even higher RPM except that’s all the fast my mill will go.

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I was running 10K RPM at 10 IPM. The Ghost Gunner won't give any higher RPM, otherwise I'd already be running higher. I may back the feed rate off to 5 IPM and set a target depth of .01" with multiple passes no greater than .0025". That should improve things. As you can see from the first attempt, the design is actually pretty clean.

Any downsides to running a feedrate too slow in aluminum? Is there a sweet spot or is slower always better?

Posted: 9/23/2018 11:42:41 PM EDT

[#13]

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Quoted:

Any downsides to running a feedrate too slow in aluminum? Is there a sweet spot or is slower always better?

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Yes, the sweet spot in aluminum is actually smaller than in steel. If you go too slow, you get rubbing and reduced tool life. If you go too fast, your tool is likely to break. That’s why it is important to use a feeds and speeds calculator.

Moving to CNC has been a revelation to me. I previously used a Bridgeport, and basically hand cranked and tried to keep things sounding good, literally. Now with the Tormach, I always use a feeds and speeds calculator, and very rarely break end mills. I’m still really new to CNC, but I’m really enjoying learning about it. CNC is amazing.

Posted: 10/6/2018 7:37:07 PM EDT

[#14]

Damn! Wish I could afford a Tormach. Oh well, my GG2 did some decent NDS lowers recently but I still have a problem now and then with one sidewall thicker than the other despite all the tricks I've tried from the FB group that post a lot of files to use.

Posted: 10/6/2018 8:01:12 PM EDT

[#15]

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Quoted:
Damn! Wish I could afford a Tormach. Oh well, my GG2 did some decent NDS lowers recently but I still have a problem now and then with one sidewall thicker than the other despite all the tricks I've tried from the FB group that post a lot of files to use.

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Have you tried billet 80%? Not much the DD can do if the buffer tube is drilled slightly off.

Posted: 10/6/2018 9:13:21 PM EDT

[#16]

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Quoted:
Damn! Wish I could afford a Tormach. Oh well, my GG2 did some decent NDS lowers recently but I still have a problem now and then with one sidewall thicker than the other despite all the tricks I've tried from the FB group that post a lot of files to use.

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The main issues I had with the GG (my machine is one of the first, from the initial pre-buy) are that originally the power supply was not robust enough for the machine (constantly stalled out), and it cut the selector holes out-of-spec (slightly oversize). Since getting the upgrade (new power supply, motherboard, and spindle - basically a GG2 stuck in a GG1 chassis), it has run like a champ. I switched to doing my holes with a jig and drill press (actually quicker than setting up a GG cut). No real issues now, except trying to engrave.

The problem with engraving is that the lower is vertical with the bit making contact from the side. The jig for holding it in this position is meant for cutting the trigger and selector holes, which are much closer to the jig's anchor point. When you get all the way out to the magwell, there is little support, so you have issues with being out of square and flexing. One guy has gotten successful engraving by embedding a probing routine that sets Z every time the cutting tool moves more than 5mm from the previous probing point. It seems that's what it takes to get a consistent result when trying to engrave, but this is beyond my ability (I'm not running a probing routine at all, I'm just moving the tool close, loosening the nut, bringing the tool into direct contact with the lower, then tightening the nut and setting Z zero at that point). I know why I got the results above, but haven't worked out solutions. The reason the first cut didn't work out was because the lower wasn't square (so I got only part of the design cut). The part that it did engrave looked decent, but that doesn't matter when the bit didn't even touch the lower during most of the cut. The final attempt was trying to compensate for being out-of-square with depth of cut. As everyone can see, the results were horrible - way too deep, and pressure from the bit was causing the lower to flex (resulting in distortion and really messy lines). I think the solution is going to be a combination of finer bit, shallower cut (multiple passes), reduced feedrate, and trying to figure out how to better stabilize the workpiece. I think a shallower cut alone will go a long way toward improving results (the first attempt was very shallow and the results were decent - at least where the bit made contact).

I'm going to keep working on it, but for now I am nervous about making an attempt on one of my non-scrap lowers (I don't want any $135 mistakes). I especially don't want to screw up my prototype lower, which would be much more expensive. For now, I'm probably going to send my 601 and 605 projects to braceman, and my prototype to Ident (since it's a firearm, not an 80%). In the meantime, I'll keep trying, since I eventually want the capability to engrave myself (even if only for SBR markings).

Posted: 10/6/2018 10:58:34 PM EDT

[#17]

That’s cool. Please post your future efforts. My current project is to do a half-way decent A1 imitation from an 80% A2 lower. I don’t have the skill to do a good solid model in Fusion 360 yet, but I’m working on it.

Posted: 10/6/2018 11:01:24 PM EDT

[#18]

Quote History

Quoted:
Damn! Wish I could afford a Tormach. Oh well, my GG2 did some decent NDS lowers recently but I still have a problem now and then with one sidewall thicker than the other despite all the tricks I've tried from the FB group that post a lot of files to use.

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Wow. That’s interesting. How do you set work offsets on the GG? I assume that’s where the problem lies...

Posted: 10/7/2018 12:00:41 AM EDT

[#19]

Quote History

Quoted:
That’s cool. Please post your future efforts. My current project is to do a half-way decent A1 imitation from an 80% A2 lower. I don’t have the skill to do a good solid model in Fusion 360 yet, but I’m working on it.

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Quoted:
That’s cool. Please post your future efforts. My current project is to do a half-way decent A1 imitation from an 80% A2 lower. I don’t have the skill to do a good solid model in Fusion 360 yet, but I’m working on it.

I hate Fusion 360 for CAD, but love it for CAM. I do all my CAD in Rhino 3D.

Quoted:
Damn! Wish I could afford a Tormach. Oh well, my GG2 did some decent NDS lowers recently but I still have a problem now and then with one sidewall thicker than the other despite all the tricks I've tried from the FB group that post a lot of files to use.

I'm in the same FB group. Have you tried the MODIFY X-AXIS OFFSETS tutorial in the documents section? It improved my results. Here is the text (without the pics):

THE EXAMPLE USED HERE IS A MIL-SPEC AR15 LOWER BUT THIS WORKS WITH AR15, M4, AR10, NON-MIL-SPEC, ETC LOWERS.

MEASURE THE ACTUAL WIDTH OF YOUR SPECIFIC MAGWELL. THIS IS A MIL-SPEC DRAWING BUT YOU MUST MEASURE YOUR REAL LOWER WITH A REAL MEASURING DEVICE SUCH AS A DIAL CALIPER!

DIVIDE THE MEASUREMENT BY 2. THIS IS THE DISTANCE FROM THE CENTERLINE TO THE WALL WHERE YOU WILL PROBE WITH THE ¼” END MILL AS SHOWN.

IN THIS CASE, .898/2=.449” BUT WE WANT THE CENTER OF THE END MILL ON THE CENTERLINE OF THE RECEIVER, NOT THE EDGE OF THE END MILL ON THE CENTERLINE OF THE RECEIVER.

SO, AFTER FINDING THE DIVIDING THE MAGWELL WIDTH BY 2, YOU MUST SUBTRACT THE RADIUS OF THE ¼” DIAMETER END MILL, WHICH IS 1/8” OR .125” TO PLACE THE CENTER OF THE ENDMILL AT THE CENTER OF THE LOWER. FOR MIL-SPEC LOWERS, .898/2=.449”. .449-.125=.324”!

THIS DRAWING ILLUSTRATES THE ORIGIN OF THE X-AXIS AT THE CENTERLINE OF THE LOWER.

SO NOW YOU HAVE THE X-AXIS OFFSET FOR PROBING AND IT’S PROBABLY NOT .324”. NEXT YOU WILL NEED THE FOLLOWING PROGRAMS (THIS IS FOR A WINDOWS COMPUTER ONLY). 7ZIP: AND NOTEPAD++

NOW YOU ARE READY TO MODIFY YOUR .dd CUT FILE PROBING

TO PRESERVE THE ORIGINAL FILE BEFORE MODIFYING IT, JUST RIGHT CLICK THE FILE AND CHOOSE COPY.

NEXT, RIGHT CLICK A BLANK AREA AND CHOOSE PASTE

NOW I HAVE A COPY OF THE ORIGINAL .dd FILE TO MODIFY WITHOUT DAMAGING THE ORIGINAL. THE ONLY PROBLEM IS THAT I DON’T LIKE THE NAME OF THE COPY.

TO MAKE A MORE DESCRIPTIVE NAME FOR THE COPIED FILE YOU ARE ABOUT TO MODIFY, RIGHT CLICK THE FILE AND CHOOSE RENAME.

IN THIS EXAMPLE, I AM GOING TO START WITH A NON-MIL-SPEC MAGWELL WIDTH OF .946”. .946/2=.473”. .473-.125=.348”. MY X-AXIS PROBE OFFSET IS THEREFORE .348” AND I WILL USE THAT IN MY NEW FILE NAME.

RIGHT CLICK THE NEW .dd FILE AND USING 7ZIP, EXTRACT THE FILE TO A FOLDER OF THE SAME NAME AS THE .dd FILE AS SHOWN IN THE PICTURE BELOW.

AND HERE IS THE FOLDER CONTAINING THE CODE TO EDIT. JUST OPEN THE FOLDER.

AND THE PROBING CODE YOU WANT TO EDIT WILL BE IN THE CODE FOLDER SO OPEN THAT FOLDER NEXT.

YOU NOW WANT TO LOCATE THE PROBE_WELL.TXT FILE (THE LEADING NUMBER MAY NOT BE 03_ AS SHOWN IN THIS EXAMPLE). RIGHT CLICK THE FILE AND SELECT PROPERTIES FROM THE DROPDOWN.

YOU CAN USE THE DEFAULT PROGRAM NOTEPAD TO OPEN THE FILE AS SHOWN BELOW BUT I PREFER NOTEPAD++ SO I WILL PICK CHANGE AS SHOWN.

PICK THE DEFAULT PROGRAM TO EDIT .TXT CODE FILES AND CLICK OK. IN THIS CASE I PICKED MY FAVORITE NOTEPAD++.

THE PROPERTIES WINDOW WILL NOW INDICATE THE DEFAULT EDITING PROGRAM FOR THE PROBE_WELL.TXT FILE AND ALL OTHER .TXT FILES ON YOUR COMPUTER.

CLICKING OK IN THE PROPERTIES WINDOW FOLLOWED BY OPENING THE PROBE_WELL.TXT FILE WILL OPEN YOUR DEFAULT PROGRAM (NOTEPAD++) AND YOU ARE READY TO EDIT THE X-AXIS OFFSET. IN THIS EXAMPLE, I WILL BE CHANGING THE X-OFFSET IN LINE 36 AS SHOWN BELOW.

NOW, USING THE NUMBER YOU CALCULATED FROM YOUR ORIGINAL MAGWELL WIDTH MEASUREMENT, CHANGE THE X-AXIS OFFSET TO PROPERLY CENTER YOUR END MILL WITH THE RECEIVER CENTERLINE AFTER PROBING THE X-AXIS. NOTICE I CHANGED .324 TO .348 ON LINE 36.

IN NOTEPAD++, CLOSE THE TAB TO SAVE THE CHANGE. CLOSING NOTEPAD++ WITHOUT FIRST CLOSING THE TAB WILL NOT SAVE THE CHANGE!
SAVE YOUR CHANGE!!

NOW YOU CAN BACK OUT OF THE CODE FOLDER. IN THIS CASE, I SIMPLE USED THE BACK ARROW IN WINDOWS FILE EXPLORER.

HIGHLIGHT ALL OF THE FOLDERS AND FILES IN THE CURRENT FOLDER AS SHOWN BELOW.

RIGHT CLICK THE HIGHLIGHTED FOLDERS/FILES AND SELECT 7-ZIP / ADD TO “WHATEVER NAME IS DEFAULT”.ZIP ABSOLUTELY MAKE SURE YOU ZIP YOUR SELECTED ITEMS TO A .ZIP ARCHIVE AND NOT TO A .7Z ARCHIVE. REPEAT: ADD TO ZIP NOT TO 7Z

NOTE THAT YOU HAVE A NEW .ZIP FILE BUT DDCUT WILL NOT RECOGNIZE .ZIP FILES SO YOU WILL NEED TO RENAME THE .ZIP FILE TO .DD

SIMPLY RIGHT CLICK THE NEW .ZIP FILE AND CHOOSE RENAME.

NOW CHANGE THE .ZIP EXTENSION TO .dd

CLICK YES TO ACCEPT THE CHANGE. INSTEAD OF BECOMING UNUSABLE, THE FILE WILL NOT BECOME USABLE TO THE DDCUT SOFTWARE.

AND YOU NOW HAVE A NEW .dd CUT FILE WITH THE CHANGED X-AXIS PROBING OFFSET SPECIFIC TO YOUR LOWER!

JUST IN CASE THIS ISN’T CONFUSING ENOUGH;
IF THE LEFT OR LOWER WALL OF YOUR RECEIVER IS THIN, THE ENDMILL IS ZEROING TOO LOW AFTER PROBING AND THE X-AXIS OFFSET NUMBER IS TOO LARGE.
IF THE RIGHT OR UPPER WALL OF YOUR RECEIVER IS THIN, THE ENDMILL IS ZEROING TOO HIGH AFTER PROBING AND THE X-AXIS OFFSET NUMBER IS TOO SMALL.
SO FAR, I HAVE SEEN AR15 LOWER WITH X-AXIS OFFSETS FROM .304 TO .349. AR10 LOWERS ALSO VARY WIDELY AND DUE TO THE LARGER MAGWELL WIDTH, EXPECT YOUR OFFSET NUMBER TO BE IN THE .400’S.
GOOD LUCK!

Posted: 10/7/2018 12:00:24 PM EDT

[#20]

Had some free time today, so I made another attempt. This time I used a .3mm 15 degree tip engraving bit. Maximum depth of cut .01". Four passes at .0025". Slowed to 5 IPM feedrate. Took almost an hour.

Cut looks clean. A lot of detail was preserved (I think you can almost make out that the TM circle is a tiny smiley face).

Still a little nervous about doing this to one of my good lowers. Will probably try one next week, after I apply the lessons learned to my manufacturer's rollmark cut file and test it too. If that looks good on this scrap lower, I'll engrave one of my NoDaks.

https://www.youtube.com/watch?v=EiyRITls4bE

Posted: 10/7/2018 1:54:57 PM EDT

[#21]

Engraving

https://www.youtube.com/watch?v=EiyRITls4bE

Posted: 10/7/2018 11:03:57 PM EDT

[#22]

Yes, I'm in that FB group using my wife's account as I don't have one. I've used that doc before but find there's a latency in the centering cuts reaching the arduino board so it's not consistent. I've done 2 exact manufacturer lowers with same offset and had one perfect the other not. I wish I could have a better way to check the centering of the GG. And yes I have the spindle mod.

Posted: 10/19/2018 8:29:25 AM EDT

[#23]

I bought a jig from a guy on the FB GG group that stabilizes the front of the lower for engraving purposes. It's a huge improvement. Having a different problem now. I've been trying to engrave a couple of anodized lowers and I'm getting a fade effect similar to when the Z axis isn't square, but for a different reason. The anodizing is wearing down the bit to the point that it no longer cuts before the engraving file is complete. I'm working on my two Brownell's A1 lowers (I got the "COLT AR-15" and horsey, but it faded halfway through the word "PROPERTY" on the first one). I think I need to break up engraving files for anodized lowers into smaller chunks so I can re-zero Z and replace the bit if necessary. Going to fill the partial "PROPERTY" with SteelStik and sand smooth, haven't decided if I will try to re-engrave the text or if I will leave it at just the logo. Will test smaller/multiple engraving files on the second Brownell's A1 lower tonight. I also reduced my feed rate to 3 IPM and cutting depth to .001 for anodized lowers - seemed to help a lot, but the bit I'm using is so fine it just doesn't hold up to anodizing (.3mm tip, 15 degree angle). These are very good lessons before I attempt to tackle the anodized surface on my prototype lower. After that, I'm not engraving any more anodized lowers (I don't want to use up 3-5 bits per lower at $15 each). I'm having no issues at all with raw lowers now - planning to engrave my raw 601, 605, and 609 this weekend.

Quoted:
Yes, I'm in that FB group using my wife's account as I don't have one. I've used that doc before but find there's a latency in the centering cuts reaching the arduino board so it's not consistent. I've done 2 exact manufacturer lowers with same offset and had one perfect the other not. I wish I could have a better way to check the centering of the GG. And yes I have the spindle mod.

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If not for the odd perpindicular work surface setup, I would almost want to write a file to run after setting zero manually (when I used to use CNC equipment to build guitars, I would set X/Y zero using the pinpoint of an engraving bit centered on a mark on the workpiece, then switch to my actual cutter and set Z zero). I trust my calipers more than I trust a GG probe routine. Unfortunately, you can't see well enough to do that with a GG.

Posted: 10/19/2018 11:06:13 AM EDT

[#24]

I do my engraving with a 1/32 ball end mill 10,000 rpm, 5 IPM, .005 DOC max. What kind of end mill are you using? These 1/32 surplus solid carbide ball end mills are cheap and good at $8.50 each. Your tool life should be much better than that.

Posted: 10/19/2018 11:19:37 AM EDT

[#25]

I'm using these:

https://www.amazon.com/gp/product/B07DBXG21W/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

They work great and hold up well on raw aluminum, I'm only having trouble with anodized aluminum.

Just ordered some of the 1/32 surplus bits you recommended.

Posted: 10/20/2018 2:20:40 PM EDT

[#26]

I don't know if things have changed because this has been some years back--------but I remember Braceman saying anodizing was too hard on his bits.

Posted: 10/20/2018 5:17:20 PM EDT

[#27]

I've pretty much given up on engraving any more anodized lowers. Not getting good results and I'm using up too many bits. The last anodized lower I'm going to do is my prototype lower, because I don't really have any other option if I want markings for it. Going to wait and do that one with the ball-end bits VAAR recommended.

A few years ago, I had SBR markings done on a lower at a local trophy shop. They broke five bits doing the engraving and told me they wouldn't do any more.

I'm doing a 605, 609, and 601 today. Will post pics later when I finish.

Posted: 10/20/2018 5:55:34 PM EDT

[#28]

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I've pretty much given up on engraving any more anodized lowers. Not getting good results and I'm using up too many bits. The last anodized lower I'm going to do is my prototype lower, because I don't really have any other option if I want markings for it. Going to wait and do that one with the ball-end bits VAAR recommended.

A few years ago, I had SBR markings done on a lower at a local trophy shop. They broke five bits doing the engraving and told me they wouldn't do any more.

I'm doing a 605, 609, and 601 today. Will post pics later when I finish.

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I have found it best to engrave a raw lower, trying to engrave a type III anodizing with most of these machines is frustrating.

Posted: 10/20/2018 10:44:39 PM EDT

[#29]

Did these today. I'm getting better, but my results still aren't consistent. These aren't perfect, but will suit my purposes for now. Going to do another 601 tomorrow. This 601 didn't turn out as good as the test piece (probably won't matter because after anodizing, I'm going to beat it up to match my original handguards). Had to run the manufacturer markings twice on the 605, should have switched to a fresh bit for the second pass.

BTW, it's hard to take a good photo of something shiny. They look way worse in this pic than they do in person.

Posted: 10/20/2018 11:35:19 PM EDT

[#30]

Those look good, will look better when finished. I’d call it good and have a beer. Lol.

My latest project is trying to engrave retro markings on barrels. Someone showed me how to engrave on a curved surface, but now I can’t remember.

Posted: 10/21/2018 12:34:59 AM EDT

[#31]

Calling it good and having a beer sounds like a plan.

I've been working all day at a breakneck pace to get parts ready to spray/bake Norrell's later this week (The 605 is getting Norrell's since I want it to match an upper that Braceman did for me which is also getting Norrell's because I don't know if the weld in the FA hump will anodize evenly). I have three more Nodak XM16E1 80% lowers that will be getting Norrell's over their current anodizing (they matched color pretty well, but did a shiny finish) - since they are anodized, they will be unmarked, not wasting any more bits. I also have a lot of small parts that will be getting Norrell's. I'm in a hurry to prep all these parts because my wife will be visiting her mother later this week, and this gives me an opportunity to use the oven for baking the parts without any complications. I'm taking leave from work specifically to spray and bake Norrell's.

The 601 and 609 will be going off for anodizing next week. I plan to age the 601 to match the real 601 furniture that's going on it, so it's going to get worn, scuffed, and beat up anyway. I do have an extra 601 lower that I can engrave tomorrow to see if it turns out any better (going to need to engrave it at some point anyway), just have to open up CAMBAM and change the SN.

Would you believe the best engraving I did today was the name and city/state on the front of the 609? It's going to be an SBR eventually. I was really sweating my makeshift workpiece holding for that cut (a screw through the front takedown hole, and a screw on each side to keep it from shifting left or right, with a nut on the right screw holding the lower flat, and half the lower hanging out of the Ghost Gunner).

Posted: 10/21/2018 11:55:03 AM EDT

[#32]

Wow! How do you zero that to get your axes?

Posted: 10/21/2018 12:14:32 PM EDT

[#33]

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Quoted:
Wow! How do you zero that to get your axes?

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Used the edge of a ruler to square up the Y axis, lowered the bit by .1 mm increments until it touched to set Z, and crossed my fingers for X.

Posted: 10/21/2018 1:11:53 PM EDT

[#34]

You would love working with a decent CNC mill. I use a Haimer to set work offsets.

Posted: 10/21/2018 1:52:13 PM EDT

[#35]

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Quoted:
You would love working with a decent CNC mill. I use a Haimer to set work offsets.

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Before TechShop went bankrupt, I used a ShopBot for wood and shell inlay. I had access to a Tormach and a Haas for metalwork, but wasn't engraving lowers then and didn't want to run afoul of BATFE's idiotic opinion regarding completion of lowers on rental equipment for my other 80% work.

I miss having access to good equipment.

Posted: 10/21/2018 8:25:55 PM EDT

[#36]

Second 601. Much better, but the "S" in SAFE is barely there. Don't know if I should try to engrave another over it.

I'm done engraving for a while. The only two projects that will still need engraving are my prototype and my 607 when it gets back from having the stock done.

Edit: Rolled the dice on re-engraving the "S" in SAFE. Nailed it. Evidently I didn't move my t-slot nuts at all when I removed the part after engraving. I tightened the jig in place and set X to 4.8mm (X is always 4.8mm with this cut), and lined up Y with the mark I made on the lower. It was at -109.2mm - exactly where it was for the initial engraving (I always write down my machine coordinates when I set zero). I set Z zero directly on top of where the "S" goes. Ran a modified file (I basically removed everything but the "S" in my previous engraving file, keeping the same coordinates for the "S"). Couldn't have asked for better placement, which is a miracle considering how difficult the GG can be.

Done with this engraving stuff for a while. Time to get ready to spray Norrell's.

Posted: 10/24/2018 10:40:02 AM EDT

[#37]

One thing that didn’t occur to me earlier. Are you using coolant? Idk how the GG is set up. If you’re not using some kind of coolant, that may be why your tool life is short.

Posted: 10/24/2018 10:46:48 AM EDT

[#38]

VAAR. You don't use coolant on the GG

Posted: 10/24/2018 2:15:38 PM EDT

[#39]

Quote History

Quoted:
VAAR. You don't use coolant on the GG

View Quote

This. Even the tool life for the 1/4" cutters I use to mill the fire control pocket is shorter than would ordinarily be expected. The GG wasn't designed to be efficient or user friendly for anybody who wants to use it outside its core purpose, it was designed to be plug-and-play to finish 80% lowers.

The bits VAAR recommended arrived yesterday. Only have two more lowers I'm planning to engrave, a 607 (which is out having the stock fitted) and a Nodak prototype (which is going to be a pain because it is anodized). I sprayed Norrells on the 605 yesterday, the engraving looks better with finish. I'll post pics later.

Posted: 10/24/2018 2:59:43 PM EDT

[#40]

Remember to keep your speed up. I recommended those mainly based on cost. They stick out more than some, so using the correct speeds and feeds are important...

Posted: 11/14/2018 8:10:56 PM EDT

[#41]

I just stumbled upon this thread. Looks like you are doing some good work with that. I saw the reference to ghostwriter and just wanted to mention that there have been some MAJOR improvements to that site over the past month or so. Probably worth another look.

Posted: 11/14/2018 8:49:55 PM EDT

[#42]

Quote History

Quoted:
I just stumbled upon this thread. Looks like you are doing some good work with that. I saw the reference to ghostwriter and just wanted to mention that there have been some MAJOR improvements to that site over the past month or so. Probably worth another look.

View Quote

Yes, I've been following on the GG FB page. Matt and Gunnar are doing great work.

[ARCHIVED THREAD] - Testing engraving on my Ghost Gunner

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