This is something I have long wondered. My concern is the deep pocket in 7075 aluminum. I’m not sure if the factory z axis or speed of the spindle could handle it. I would think you would need a 1/4" endmill to prevent runout at the depth you need to plunge. Anyone ever tried it?
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I feel like I’m always the guy trying crazy things first. I sure wish I could learn from someone else’s mistakes on occasion 
I think I would need to upgrade my Z axis and increase the height at minimum. I’m pretty certain I’m going to need to drive a 1/4" endmill to finish that pocket, and I’m not sure if the factory dewalt spindle can even achieve an acceptable chip rate at it’s minimum speed.
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stock machine wouldn’t be possible.
stock z would be first concern, need the travel for cuts required with lower in vertical position.
also anything to help stiffen up the machine for aluminum would help.
makita router (slower spindle rpm) would be helpfull.
guys seem to cut 6061 with the right feeds and speeds. 7075 is a little harder, but the chip cuts away easier.
thoughts that come to mind
Seems like we have the exact same concerns.
I know there have been a few developments on the Z axis situation. I think Phil upgraded his awhile ago. I think I remember him having some bearing problems or something of that nature? Did you ever get the figured out? What’s the best option right now for stiffening up the z axis? You’ll have to forgive me, I don’t wander in here too often.
from my experience.
the X-Carve is not suited for this out of the box. it uses belts to drive the gantry and this allows to much slop or play into the equation.
I remember reading on the site that makes the cnc just for this that it doesn’t take a small layer after small layer when it cuts the lowers. they run the machine in at full depth and use the end mill to cut. this can be done as their machine is ridged enough to take the stress from that type of cut. they also made a statement that if you take multiple shallow cuts that it would dull the bottom of the end mill and reduce the quality of the cut.
now if the x-carve was modified (like the 500X500 size) and had screw drives (no belt to slip or stretch) and was ridged enough. then sure why not.
Also you can download the plans for the CNC that is made just for this function on that site that sells them. it is also open sourced designed. you can look at what is different from the X-Carve.
I have the X-Carve and also have a friend that has the other CNC for this. I was surprised at how light and small it was. I was expecting something larger.
good mentions @KennethConnell1
another aspect to consider is a more capable CAM option such as Fusion 360.
you’d wanna take advantage of adaptive clearing and the feature set in a true CAM program.
this will help with material removal and you can take a final pass to size.
@C.j.Shull I’d lurk the upgrade section for ideas and search some of these items;
500 X Carve (stiff)
Upgrade Belts (9mm 3GT2 belting)
Linear Z upgrade
Taller end plates
Y extrusions bracing
Makita router
If dudes can make it happen on a cheap ol’ drill press and a fixture you got a decent chance with some of those upgrades above.
No I was not talking about that machine I was talking about the ghost gunner CNC just for this function.
I assumed you were talking about a GG machine. $1,200 bargain for one use.
I think I’ll just pick up a 5D router jig for $250 and call it a day. My Dewalt 624 tears through aluminum like a breeze. I’ll do the engraving with my X-carve though.
that what I have done. and with Bcnc I found the engraving is fairly easy and reliable.
as far as using the jigs it was not hard at all. but then I found a guy local that had the GG and had a chance to stand before it and I was really surprised, I had envisioned it being much larger and heavier than it was.
never got to turn it on though.
but if you was to try this on the X-carve I would really consider getting the screw drive for the X and Y axis and just get rid of the belt system all together.
sad part is that jig also uses the spindle dewalt 611. Seems like a defeat to me to have to use my hands to do the job the machine can’t handle.
true but would a belt slippage be worth it?
I would not want to take the chance as I have had slippage on wood if things were to aggressive.
FWIW - my CNC use ACME screws on all axes, Nema23/269oz motors running @ 3A
410x350x70mm work area
Makita RT0701 router
With a quality 6mm 1F alu bit I can chew aluminium with the following speeds (tested):
RPM 22k (Makita #4) aiming for a chip thickness between 0.04-0.05mm/tooth.
=> Feed 900mm/minute
Depth per cut (DoC) 2mm running single line (width of cut 6mm)
DoC = 2 is probably my max, it is more audible than DoC 1mm with the same settings. With DoC=1mm is seemed it could run that all day. Plunge rate moderate at 150mm/min.
Adaptive carving, throchoidal:
RPM 22k (Makita #4)
Feed 900mm/min
Depth per cut 6mm with 2mm stepover.
Rough, but didn’t skip a beat.
I have a very solid Z-assembly, strong in Y but my X is the current weak spot.
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yes they do. just do a quick Google search and there should be plenty of information.
then you should be a perfect candidate if you would experiment for all of us.
I just would not want to take a chance with my X-Carve doing this as there is way to much room for error and I am not one to throw away a good lower for that belt slip.
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I needed to google what a 80% lower receiver actually was, what depth is required for your intended operation?
Got any images to highlight the area of interest?
I’ve been wanting to try this on my cnc, but haven’t got to it yet. I bought 80% lower from Anderson that I finished with their drill press jig. I feel like I can definitely do better with my cnc than I did on the drill press. I would mill the trigger pocket out on the cnc and then use a jig with the drill press to drill out the pin holes, since I already have the jig and it doesn’t take long. Hogging out the pocket with my drill press and fine tuning it with a file took me forever. I know there are better jigs out there though. I’m definitely gonna try it on the cnc one day.
you finished out the whole pocket with a file???
wow. That would take forever, I used the router from the x-carve (Dewalt 611) with the 1/4 inch end mill and the jig plate.
I would drop about 1/16 inch deep and re-carve the area over and over. took about an hour.
I had the jig from Anderson which allowed me to get most of the pocket out with the drill press. I didn’t have a router at the time so I used a dremel to remove what was left over. Really the only part I had to file was some of the sides of the pocket to smooth them out. But it still took me quite a while.
