Hi everyone!
I'm an electrical engineer by training, mechanical engineer by trade, our company's additive manufacturing subject matter expert by default, and a machinist by the absolute seat of my pants.
My base of experience in machinist work extends to manual mill & lathe work, tig welding, and CNC programming and machining using DIY routers, a bridgeport torq-cut 22, and a Tormach 770.
With a big-boy job and some reliable income, I wanted to land myself a large, capable machine able to perform (to some degree) a combination of the work I've been doing on both routers and VMCs for my projects at home, and in pursuit of a business involving carbon composite tool production.
I was looking, rather unsatisfied, through 6040 router builds and applying for financing options to get my hands on a proper garage VMC (ideally a Syil X7, backup being tormach 1100 MX), when this 20-year-old Multicam MG101 caught my eye on craigslist for $3600:
I've clearly already started pulling parts off and cleaning this up. My thought is that with modern controls, servos, and motion hardware upgrades, this could be a serious machine for all my needs right up to (and in a very limited capacity including) mild steel.
I bought it from a sign shop who had used it for 20 years and (bless this guy) "greased it every 2 weeks". Certainly can't say you didn't. Never bothered to wipe any off either:
They were using a high quality Mobil moly grease, and they really did seem to keep up with it. The machine was very tight when I went to take a look, no measurable slop other than a few tenths of deflection in X and Y, the Z is another story. 20 years of travel over the same 2" on this poor, poor leadscrew:
All their work was entirely 2D, so they didn't care or even notice. Obviously since I'm doing surfacing work, this needs to be replaced with a ballscrew.
The X-axis runs on a 1" OD X 64" multi-start leadscrew, and the thing is still tight. Moves freely with no measurable lash. That said, the pitch is very high and is going to leave a lot desired in terms of positioning accuracy. I'm looking to replace this with a rolled ballscrew:
I was delighted to hear (and see paper evidence) that the spindle had been rebuilt in the last year. Feels great, no runout, noise, or visible damage to speak of:
In total, my wishlist is as follows (for now):
- Centroid Acorn CNC Controller
- 4X DMM DYN4 & 86M-DHT-A6MK1 servo kits
- Z-axis ballscrew retrofit
- X-axis ballscrew retrofit
Future work including:
- 2.2kW ATC spindle & tool rack
- Y-axis ballscrew conversion (if the rack & pinion is as terrible as I'm reading)
I'm super excited to get to work on this thing, and am about to pull the trigger on a lot of the controls. I chose the DMM DYN4 & 86M-DHT-A6MK1 as (as far as I can tell) a more powerful and more economical alternative to the similar Teknic offerings NEMA-34 frame. Let me know if I've misread the existing options.
Additionally I'm definitely going with chinese rolled ballscrews to make this a practical DIY build. Does the community have a preferred brand/supplier for motion hardware like this? I know there's a lot of garbage out there...
Cheers,
- Feathers