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I played around with this design once, it seems like a good space saving layout and novel because no one does it, but there's reasons for that. As previous responses have pointed out, most of your...

Hey Stef, quite a few combat robot builders who took the plunge into DIY CNC here to feed the hobby. Love your bots and your mill build!

Zach

Yep, new spindle fixed the runout problem, must've bent the old one while hammering on tool steel with a big indexable cutter. Guess my machine just doesn't have the rigidity for that kind of work. ...

An earlier version had the xy bearings bolted to the same saddle plate but as you noticed accessibility to the bolts was very restricted and difficult to work on. I modified the design so the xy...

Hey Mike, I used US Composites 635 Thin Epoxy with 3:1 medium hardener and mixed it with as much iron oxide as possible until it got too viscous to inject using a plunger. That was about 20/80 ratio...

Bridgeport type mill operations can reasonably apply ~200lbs average, instantaneous loads will be higher especially hammering on a piece of steel with an indexable cutter. Need a minimum 300-400lbs...

Experience usually trumps analysis and since you already bought the belts, may as well give 'em a try.

Basically the XL belt will be loaded 3 times more than "recommended" during quick moves or heavy cuts whereas the 5M GT2 belt is within its rating. Exceeding the recommended tension intermittently is...

I rescind my endorsement for HTD belts, turns out they have more clearance than trapezoidal tooth form. Granted mounting the encoder to the ballscrew shaft would prevent this from causing positional...

Wish I had a torque-speed curve to illustrate that those servos will far exceed steppers performance-wise but you absolutely must gear them down. 4:1 ratio would allow over 200IPM rapids on 5mm lead...

$600/axis sounds pricey, automation tech sells a 3 axis kit for $320/axis plus the belts and pulleys for gear reduction. If you're willing to wade through broken English manuals and take some risk...

It's an X2 "mini mill" spindle, supposedly hardened and there are signs of discoloration from heat treating on the non-ground surfaces. It has an alignment pin so collets always go in the spindle...

My wee mini mill spindle has developed some rather excessive runout. About 0.0025" at both the end of the internal R8 taper and external dia. When new, it was only about 0.0005". At first I thought...

Here's the conclusion of this project Stbrnrd, another thread was started since this one veered off track. Theres obviously a large gap in the design evolution which was not shared since I didn't...

Long time no post. Looks like most of my old posts/pictures were trashed in the update to the new forum, bummer. Hope the mods can recover them. Seems like theres a few other bugs from the...

I've had decent results with the R8 mini mill spindle.

http://www.cnczone.com/forums/vertical_mill_lathe_project_log/123787-zachs_homebrew_cnc_mill.html

The stock bearings are deep groove...

Mach3 has a charge pump circuit driver built in. It's a 5khz step pulse so like enabling another axis. I use it on my BoB, should put minimal additional strain on Mach.

As far as your spindle,...

Stress relieving most steels: heat to 1200F which lowers the yield strength to allow plastic deformation as a result of the residual stresses and hold at temperature for a couple hours. Longer...

I'd take a video of flood coolant except my mill has been crated up for the past couple months while I relocate for a new job in Houston.

Correct, in my application the purpose of post weld stress...

I heard my name so I guess I'll weigh in. Don't worry about machining the ballscrew ends, with a good carbide insert and stiff tooling setup you should be able to get through the case hardening...

Hey neat axis setup. I had been considering doing a full moving gantry for awhile but as I planned out how to fabricate and align everything, a more traditional bridgeport layout seemed far easier to...

It's a combination of both. I need to get a tension gauge to get some quantifiable measurements but I'd say I'm applying in the vicinity of 100 lbs of force. If I pull only on the mill head i can...

Thanks wizard. In my application the E/G granite fill increases the stiffness of the structure by around 3 times. However if I bumped the exterior wall thickness from 3/8" to 5/8" and ditched the...

Thanks for the questions and praise guys, its what keeps me posting updates! Danande, according to Alcoa MIC-6’s flatness tolerance is 0.005" for plates 3/4" and over. I'd recommend using something...

It's probably good Chai stopped shipping them with seals. I actually removed them because they were so tight they generated enough friction to start smoking! My fixed end blocks are well protected...

The angular contact bearings in it are not a matched set, plus on a couple of mine the bearing hole was bored too deep. I had to shim several thousandths using arbor spacers from mcmaster (not the...

Thanks for the advice Lucky, I'll have to give that a try once I finish up the mill. Wonder if there's a standard part to machine that I could do some metrology on and characterize my mill's...

I've achieved a state of functionality! Lost interest for awhile, then got back into it. Did some more shimming to square up the table and tightened down some things to work out some backlash in...

Ive often wondered whether large r/c brushless hobby motors would work as spindle motors. Take for example HobbyKing Online R/C Hobby Store : TR 80-85-B 170Kv Brushless Outrunner (eq: 70-40). For...

Thanks for the encouragement! Youll need quite alot of time and a good chunk of money. Im in about $4k now, and dont want to even think about time consumed. Granted alot of that is spent...