Gauging interest: Greyscale Racing MR-CG chassis

[Limeaway]

Page 3...His target price is $75

[color01]

Updates, finally.

The CNC stuff has finally come, after multiple threats on my part to file an eBay dispute. I got the CNC mill working, and ran a test program through it. Seems to work well, although I won't be able to see the tolerances until I build some prototype parts. At any rate, the thing IS working at least, so I can finally legitimately say I'm on my way to getting this chassis produced for those interested.

[byebye]

Cool man looking forward to some updates.

Kris

[Flashsp-2]

It sucks that it took so long to get all the equipment in, but I'm excited to see some progress. I'm still in for a chassis, thats for sure. Already have the pan body, mounted/trued foams, and electronics ready to rock. You're still going 98mm correct?

Looking forward to seeing pics of some chassis parts

[color01]

First batch of G10 prototype parts! The cut quality is no good, but it's mainly because I used a ruined endmill to cut with. The holes will be countersunk later, no worries.



I plan to get these parts made correctly before moving on to the fancy 4-axis work, so check back for updates.

[Hammer]

Originally Posted by color01

First batch of G10 prototype parts! The cut quality is no good, but it's mainly because I used a ruined endmill to cut with. The holes will be countersunk later, no worries. I plan to get these parts made correctly before moving on to the fancy 4-axis work, so check back for updates.

Very cool, thanks for the update. Also thanks for sharing your learning process regarding manufacturing, it's a great resource for those interested but not familiar with how it's done.

[color01]

I was using the wrong units! D'oh. I have the feed rates right this time, and edge quality is much better, though the cutting bit didn't go deep enough to separate the pieces entirely from the stock. (It turns out that this plate of fiberglass is slightly thicker than 1/32".)

If you look closely at the picture, you'll notice there are two "kinds" of edges. I was playing around with the settings and found that really slow speeds (6mm/min) are really good but take forever, slightly higher speeds (15-30mm/min) are terrible, and the proper speed (150mm/min) nets nearly perfect cuts (check the outside edges of the flex plates).



So that's my update. Since I have a 3-day weekend I should be able to do some more work on the fiberglass and get that all sorted out and perfect. The Delrin and aluminum parts may have to wait since I still need some screws to mount my micro vise to the rotary table. Rest assured I will get this done as fast as I possibly can!

[MikeL]

Very cool looking project, have you tested any standard electronics for fit? can you fit a novak spy and spektrum micro reciever on the top plate?

[color01]

Side by side, definitely. If you decased them both you might be able to fit one in front of the other. (I haven't checked that one yet)

The cleanest fit would actually be a Losi Micro-T board, but unless I'm forgetting something the chassis will also hold any Mini-Z board.

[color01]

Ok, I've got good and bad news.

Good news first: edge quality is perfect on the longer cuts.
Bad news: edge quality on the countersinks has gone down.
Worse news: the mill seems to jam up right around this one spot of travel. I have no idea where to look for the cure; the mill is freshly lubed up with WD-40 and the rails are clean. Yet there's a slight grinding noise and sometimes the whole thing just jams while the CNC control software believes it's still going.

Check Exhibit A:

[marc]

Hi there, do you have a way to check the gearing on the CNC machine? It might be gears binding or not meshing right. I dont' know anything about these machines, but knowing mechanics, it does sound like a gearing problem. Just a thought!

[ruf]

WD40 is not a lube. Use grease.

[color01]

I've been reprimanded for that multiple times now, lol... thanks ruf. I've lubed the machine and jogged it around the axes a couple times, hasn't jammed YET. I'll have to try running the program again to see where the problem area is. Will use styrene stock instead of wasting fiberglass.

[Hammer]

Originally Posted by ruf

WD40 is not a lube. Use grease.

Absolutely correct, WD40 actually attracts moisture i.e. corrosion & rust.

[color01]

http://en.wikipedia.org/wiki/WD-40 Slight discrepancy...

Mill is still jogging smooth. I will be really, really frustrated if it jams during the test program tonight.