What is the best value mill to cnc convert etc

[thezetecman]

I am currently using a manual mill drill this i could convert this but do not want to be with out a mill. So am thinking of buying either a X2 or X3 possibly the x2 super mill( the new one. As it has an easier Z conversion than the mill drills.

Does this look feasible and importantly reliable and accurate or is this the mill equivalent of a 1960's Lotus car. Very much an enthusiast vehicle (denial about reliability helps with ownership)

Sieg X3 or similar Price £799

Z no ball screw unwise or can I get away with this
X and Y ball screws £300

3 X 220ncm stepper motors and drivers £39.50 each

1 controller and psu from ebay around £200.

Mach3 control software£?

All mounting brackets and machining to be done by me hobby £ so no cost
I am estimating a 1 week full time project?


I will manually control the motor speed so will not modifiy the speed controller.

How reliable is the motor drive pcb on the sieg mills I found quite a few failure reports on the web.


thanks for your comments.
Regards

 

[Mainer]

I believe one can buy a CNC'd Sieg X3, so it's certainly possible to do it. My impression -- based on not much -- is that it's a decent machine.

If I were doing a CNC conversion, I would use a SmoothStepper controller with Mach3. The newly-released install/config manual, available on www.machsupport.com , has a lot of information about how to set up a machine.

I think your estimate of a week to do the conversion is wildly optimistic, but you may work faster than I do. In any case, it's a hobby, so the journey is the goal....

 

[BobWarfield]

First, avoid round column mills. They're not well suited to CNC due to the alignment issues raising and lowering the head.

In the Sieg line, there are a ton of people who have converted an X2 or an X3. For more money, you can get the much larger and more rigid RF45 from a variety of sources.

Whichever of the choices you make, the machine can be made accurate and it's reliability will be up to you. A lot of the latter is a function of the builder (like the Lotus!) and your'e it.

I would definitely NOT want to be without ballscrews, even if that meant I could only afford a smaller mill. In the end, they're actually not that terribly expensive anyway, and they are a critical component to the mill's accuracy. CNC has a very hard time dealing with backlash.

Some other thoughts:

- If it was me doing my first machine, I'd be really tempted to go the X2 route and buy hossmachine's kit for it. There seem to be more X2's out there than anything. Hoss is extremely active on CNCZone and has done some amazing things with the machine.

- If I were willing to spend a little extra time, I would consider one the "hybrid X2" setups. People are interchanging parts on these little mills to increase their capacity and rigidity. For example, you can fab together a welded pier to augment the X2's column. One fellow did this and reported his X2 was more rigid than a later X3 he CNC'd. Very cheap to do with some 4" square tubing and maybe a little concrete fill. Search "hybrid X2" on CNCZone.

- I'm not at all sure I'd recommend the Smoothstepper to a first timer. I have one, it works well for the basics, but there are some critical shortcomings. First, backlash compensation is not available. Even if you have ballscrews, it is useful. Without ballscrews, it is critical. There are other features missing, but the biggest issue is poor support. The guy that designed and built it has quit responding on their boards. Others are trying to provide support, but he hasn't been heard from for weeks. Rumor is that this is due to a big industrial contract, but it doesn't bode well for whatever reason. Get a good old-fashioned parallel breakout card and let the Smoothstepper sort itself out one way or the other.

Cheers,

BW

 

[fdew]

A friend of mine has had good luck buying obsolete full size CNC mills with non working and to old to fix electronics. He buys then at auction for pennies (2 for $100 and one for $400)
He keeps the metal, the motors, and the amps and power supples and converts them to run from PC based software.

Frank

 

[firebird]

Hi

Have a look at Arceurotrade. They sell all the bits you need and have a very helpful website. Julian converted his X1 to full cnc without ball screws, most of the parts he got from arc.

Cheers

Rich

 

[HS93]

Hi I have just about finished doing a X1 mill I got the steppers from Arceurotrade and made the rest , in manual mode it is a reasonable mill if you fit thrust bearings on the screws + bearings very smooth and I used the same parts when I went cnc it removed a lot of play , still got a bit in the nuts but i think that will be sorted very soon , only done basic test in cnc mode and it works well. I wanted it converting to help me use it as i have problems with some movements and it has sorted that for me . I used belt drives as I wanted to keep it compact and it has done this I also have the handles on as well( I fitted larger folding ones from Arceurotrade) so have the best of both , when I was doing mine I did a set of direct drive parts for a mate who did my electronics for me they work very well he is using his for PCB milling.
I have fitted a belt drive unit as it makes it very quiet and gives more range.
anyway a few pictures showing you can do quite big jobs on them if you take a little time. plus my belt drive and a picture of one of the direct drives I did for my mate.

 

[HS93]

Plus these I hope they help

Peter

 

[HS93]

and two more

Peter

 

[Tin Falcon]

I am currently slowly spare time doing a x-2 that is what I have if you have the room and funds a x-3 is a much more capable machine.
Look here ball screws and nuts for under $50 per axis
http://www.roton.com/Mating_Components.aspx?family=7059321

Do not go cheap on the control board cheap ones fry look here
http://www.geckodrive.com/product.aspx?i=14469&sb=1
This board will also control your spindle board.

The motor controllers on my mini lathe and mill did in fact get taken out by a power surge. They were repaired with less than $10 in parts. The Mill is 8 years old and the lathe 10 plus the only problem I have had.
Tin

 

[Julian]

Hi,

I converted my X1 to full cnc as already mentioned by Firebird. I manfactured everything I could including the powersupply and control box. The controllers and breakout are from Routout for about £70. Motors and oldhams from ArcEuroTrade. Everything else was made by me including new leadscrews and nuts with virtually no backlash. I recon my conversion cost me less than £250.

I don't use software to control the spindle (YET). My mill has a half hore motor hanging off the side as my electronics packed up before I did the cnc. I am just fitting a new motor on with new pulleys and belts to improve the spindle speed. Hoping for about 5-6000rpm. Without aditional oilers the original bearings are rated at 10,000 constant. Using an induction motor from MachineMart.
Hanging the motor directly behind the turret to give balance. Also got some counterweights on a simple pulley to relieve some of the weight..

A week even if full time is way too optomistic. DON'T rush it........removal and refiting when it is wrong quadruples the time taken...trust me I did it several times.

Use Mach 3 or Mastercnc (Free from Colin Usher website). If you can, have a small computer (NOT laptop) dedicated to the cnc and cut windows down to the barest system. I have a list of all the window bits that need to be turned off if you need it especially with Win XP.

Julian.

 

[Julian]

My X1 has a non-Seig motor. A while ago the control board packed up so I made my own motor concersion to use a standard single phase ac motor and belts. Have just finished rebuilding it to put this motor directly behind the turret to give balance. Made my own pulleys as I wanted a far higher top speed. Got it turning now at 4700rpm and have now raised the motor speeds in mach 3. Cuts the sample loco wheel that ArcEuroTrade uses on the cnc mills in 47 minutes with a two quid three flute endmill. I am very happy with this cnc conversion and the mill. The only thing lacking is a little more table travel but I am working on this now. If you have the space and the money the Seig X3 is an ideal machine to convert and looking at Firebirds machine would probably convert easier than my X1 did. I have found no rigidity issues whatsoever and I suspect those that do are going beyond the extremes of the machines.

Julian

 

[Tin Falcon]

Do your homework there are lots of trade offs. I started using the stirling Steele plans simple but ran into some glitches. I ended up buying a set of fignoogle plans. More wore but many advantages. I will probably end up building twice when I am done.
Tin

 

[thezetecman]

I have made my decision and it arrived today a large table X2 with the 550 watt motor.

So far I am very impressed with it the axis only has 0.1 mm of back lash the y axis and about 0.14mm though.

It can with a inspection sheet. I must admit I thought it would be made up like a place i used to work in england. But know my measurements match there measurements.

The only fault found so far is one of the T slots needs to be filled out a bit at one end.

I have tried it out milling a bit of black MS and it milled very well.


I will make my own plans for mounting the motors etc

current deciding on the ball screw pitch, 5mm seems common but the question is: are the 3Nm (425Oz in) holding, 15N max axial force, 75N radial force, strong enough motors when coupled with a 5mm pitch?

 

[Tin Falcon]

current deciding on the ball screw pitch, 5mm seems common but the question is: are the 3Nm (425Oz in) holding, 15N max axial force, 75N radial force, strong enough motors when coupled with a 5mm pitch?

Steppers have max torque at low speeds 425may be a little much unless you are going full blown gecko drives probably 270 to 320 range would be more realistic for an x-2.
check out the gecko web site they have some good info on motor sizing etc.
Bigger is not necessarily better more motor more amps more amps higher rated motor driver.
Tin

 

[Dusty1]

A friend of mine has had good luck buying obsolete full size CNC mills with non working and to old to fix electronics. He buys then at auction for pennies (2 for $100 and one for $400)
He keeps the metal, the motors, and the amps and power supples and converts them to run from PC based software.

Frank

I agree,

Full size is the way to go if you have the space.



Like the Bridgeport in the background with the AHHA retrofit package.

Mite