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Nonoriginal
02-12-2005, 11:39 PM
First, I'd like to say hello!

Second, I'm looking for plans to build a Desktop CNC. I live in an apartment and I don't have a lot of room. I've read a lot here and I couldn't find answers to some of my questions.

So far this is what I understand to be true:

The taig, MaxNC, and Sherline mini-mills take a lot of time to cut just about anything (esp.Aluminum and Steel) with stock components. It seems that folks like Jeff have upgraded Stepper size to 300+ oz. And other modifications, which takes money for the mill+money for the upgrades. I would rather skip the upgrades part and just get to mill I want.

I plan on cutting Aluminum, Steel, and Delrin. To get the type of cut I want (.100 or more per pass) I would have to buy one of the above mentioned machines and upgrade Spindle and Stepper size immediately. This is a bit of a problem, as my budget is limited.

Can anyone refute what I'm saying here? I would love to see my observations proved wrong about the mini-mills mentioned. I would rather not buy a Grizzly or Enco and be stuck with a manual machine because I can't afford the steppers or control boards.

The good news is that I'm an apprentice CNC machinist at a 5 man race shop. I have access to a lot of material at good prices. (I can get it at my owners cost) We have 3 Haas VF-4's, A Matsuura 800 VMC, Mori-seki SL2500, Slant, Bridgeport’s, Sunnen honing, Grinders, etc, etc. And I can build anything I want if I'm clocked out. However, I can't take side jobs for money on my bosses machines from an ethical standpoint. So I want to build my own.

I've searched and searched, but I cannot find plans to build a CNC VMC from scratch(tons for the router though). Anyone know where I can get some Ideas to start out? I don't care if its Chicken scratch on a napkin, we get plenty of those "prints" at work, and its my job to turn them into these:
http://www.nonoriginal.com/index.php?option=com_akogallery&Itemid=26&func=viewcategory&catid=10

Am I totally off-base in my observations regarding the taig and such?

Thanks! :drowning:

RotarySMP
02-13-2005, 04:23 AM
You'll never get .100" cuts in steel on a taig or sherline (or mini-mill).

The Swede hasa great write up on his home made VMC here:
http://www.5bears.com/cnc.htm

Rugby10
02-13-2005, 03:17 PM
I was wondering too!

JFettig
02-13-2005, 03:35 PM
I am running a converted X2 with new motor and big steppers, I have taken 1/4" with a rougher and typically take 1/8" cuts with 3/8 and 1/2" end mills, probably coudl take more, but not quite sure. I havent taken much for large cuts in steel because I havent done much steel, it still does a pretty decent job.

as for speeds, I run 1/2" end mills at about 6000rpm up to 30ipm, same with 3/8" end mills, but thats taking light cuts, I will try to push 20ipm deeper next time I make some parts, I drill at 20ipm 4000rpm with around 1/4" center cutting drills and 10ipm with 1/8" drill at probably 5000rpm. I can take .0625 with a 1/8" EM up to 10ipm at 6-8000rpm. All this in steel.
I recently drilled some holes in cast iron at 4ipm, and about 800-1000rpm, I probably could have gone faster, it went well.

If I have the money and time this summer, I want to build a machine similar to swedes but a little bigger and little different design(kinda like a haas, fixed X axis motor)

Jon
Jon

Nonoriginal
02-13-2005, 04:57 PM
Thanks for the replies!

Jon,

Impressive numbers for a small mill!

I would also like to build a machine like the Swedes. Although, it seems a bit out of reach at this point. I like the idea of building a machine like the Haas Mini-mill too... Enclosed, tool changer, fixed motors, etc. However, this would take some serious budget...and TIME! One of which I can find if I want to bad enough... and NO, its not almighty greenback unfortunately.

What about tapping on your rig? How do you do it?

How much money (if you don't mind me asking) is tied up in your mill?

If you were to start gathering the nessesary equipment to build your own machine tomorrow. Where would you start?

Personally, I need to have a plan to follow. If I could find some plans out there... I would be golden. But I just can't seem to dig any up. I actually may end up going down the router path to start.

JFettig
02-13-2005, 05:09 PM
thanx:)
I do not tap on my mill, My motor cannot handle reversing without shutting the spindle off and back on and I do not have a spindle encoder on there yet. I do all my tapping by hand. I hope to grab a drill press or something that I can reverse quickly so I can just tap like that.
I have about $3000 tied up in my machine alone if not a little more(I calculated it a while ago)
I would probably decide on what I want to do with the screws, then stepper/servo motors, get the motors and make the mounts and everything. After that I would start working out the electronics.
Mainly what I mean by haas like is how the X axis is, it moves over rather than the entire thing moving, the width of it doesnt change or shift while moving the X axis, They also use linear motion type bearing blocks similar to what swede uses.

Jon