[jonathanm]

I have recently aquired a Microkinetics "desktop mill". Calling it a mill seems a bit over optimistic....It's like the one on their website, but with less powerful motors.

Does anyone have any experience with them?

http://www.microkinetics.com/cncmill.htm

Thing is, I have no idea what I'm gonna use it for. (I'm actually building a 4x8 router for furniture - this mill didn't figure in my plans at all)

I don't even know what it's capable of. It looks a bit wimpy to me - doesn't look capable of milling aluminum. I think it was previously being used to engrave plastic name badges.

Anyone know what i can expect from this thing? My guess is just plastics, jewelers wax, PCBs maybe....

Specs -

20 tpi screws directly coupled,
half step motor controller,
1/2 hp spindle, 75-2800 rpm
x&y = 83oz in 6v
z = 112oz in 4.2v

Controller is their "Mighty Drive" - 3 of their unodrive boards in a box. 1.2A at 40v. They say it will handle up to 175 oz in.
http://www.microkinetics.com/drivesub.htm
http://www.microkinetics.com/motor_drivers/index.htm

If I upgraded the motors, could it ever do aluminum?

Any recommendations for motors? The motors recommended on the microkinetics website are $49 for 175 oz in - seems pricey.

What about a reasonably priced 4th axis? Again the microkinetics stuff seems expensive-

rotary table - $395
right angle attachment - $75 (to mount the rotary table vertically)
tailstock - $75
4 jaw chuck - $110
http://www.microkinetics.com/cnctools.htm

oh and one more unodrive at $49 (there is space for one more in the box)

Then I would have a setup like this:
http://www.microkinetics.com/4axis.htm

also I just have a drill chuck in the spindle - i guess I'll need some kind of end mill holder to do anything accurate?

Any suggestions or advice gratefully received

And oh, yeah, my first proper post here

Thanks

Jonathan

[xspyke]

It's a sherline mill. Have a look at the sherline web site. Good reading for first newbes.

http://sherline.com

[jonathanm]

Oh!

right...

I've been googling the damn thing for a couple of days, but still didn't realize that's what it was....plus I've been reading this forum for months, lol - seen the name Sherline plenty of times just never paid any attention to these small mills....so didn't put 2 & 2 together.

So companies like Microkinetics just add their electronics and resell them? I didn't find any reference to Sherline on their website or anywhere else, actually.....

So it looks like there's a ton of info about them, and also that it's a lot more capable than i gave it credit for....great news!

Thanks for pointing me in the right direction

Any advice for tooling, mods, etc gratefully received!

Jonathan

[Andre' B]

Some videos about using Sherline lathes and mills from a guy in Brazil.
http://www.youtube.com/user/tryally

[jonathanm]

thanks for the youtube link.

I see he's using it to cut steel, so yeah, I did this mill a dis-service in my initial assessment.

There is some slop in the axes, which led me to believe it wasn't very accurate - now I'm thinking it's just needing set up right.

To be honest, I was thinking I ought to just sell it to help fund the router, but it looks like it's a keeper. The problem with that is having two cnc projects on the go - one for each pocket? Neither pocket is very deep....

Looks like I'm going to need to spend a fair bit on tooling and bits and bobs for it. Where to start?

At least I can make some parts for the router on this mill by the looks of things.

Jonathan

[Greebe]

I am just curious. Why did you buy a cnc mill with no intended use for it?

Greebe

[jonathanm]

I am just curious. Why did you buy a cnc mill with no intended use for it?

Greebe

Fair question....

My friends know I've recently got into this stuff, and one of them told me he knew someone who had an old engraving machine he wanted to get rid of.

I said I'd go and take a look at it - as soon as I saw it I realized it could be fun. It was assumed to be broken, and the guy didn't know the first thing about it. I think it came out of a high school which had closed down it's shop class program. He had got it in a job lot with a load of woodworking tools and materials.

I made him a very low ball offer, and was driving home with it a few minutes later

Got it home, cleaned it up, and tried to figure out what it was, hence my confused post, lol

I've got it running now, but I have no tooling for it, and the 86oz/in motors are pretty flimsy. The Z axis has a 112oz/in motor, and it has difficulty just lifting the spindle...I want to upgrade them, but the drives only dish out 1.2A at 40v, so I think 150oz/in is going to be my max unless I get new drives and power supply.

Like I said though, I haven't finished getting all the stuff for the router yet, so now I have 2 hungry animals wanting fed......

[vlmarshall]

My little Sherline mill came from a highschool shop class, the first thing I did was pull out the electronics and stepper motors, and replace it with a Xylotex system. If I were doing it again today I'd go with a Geckodrive. I've just finished converting my new lathe, and the difference in power over the Xylotex system is just amazing.

I use my Sherline stuff to cut plastics, brass, copper, aluminum, steel, and stainless steels, they run just like scaled-down versions of the Haas and Mazak stuff I use at work.

[jonathanm]

vlmarshall, nice youtube videos

I though maybe a geckos were overkill for this mill, but maybe not....what steppers are you using?

[awerby]

it seems like it would be pretty helpful in the process of building your router. A lot of what's required is accurately laid-out mounting plates for motors, faceplates for electronics, adapters for spindles, etc. and this mill could help a lot with all that. I'd say it's a keeper.

If the electronics don't work, then look at the Gecko 540 to replace them - it's 4 drives with optoisolation and a built-in breakout board - pretty simple to get up and running with Mach3 software.

Andrew Werby
www.computersculpture.com

[vlmarshall]

vlmarshall, nice youtube videos

I though maybe a geckos were overkill for this mill, but maybe not....what steppers are you using?

Thanks!

I'm using 381in/oz steppers from Keling on the lathe, with the Gecko drives, and the performance is incredible compared to my old Xylotex-driven mill.

[jkcab]

I have an old spectralight that came with an EZCNC board and 127 oz motors. The amperage is not as big a problem as you might think. If you use a unipolar (cheap and most commonly avalable)and wire it bipolar series you use half the rated amps. If you know the inductance, multiply that by 4 and take the square root of that number times 32 and that will be optimal voltage. Example: Motor six wire, 280 oz, 3amp and 1.4mH, would be; 1.5amp and 1.4x4=5.6. Take the square root of 5.6(2.366)x32=75.75 volts. At about half the volts on the power supply you should be able to tune the system to run fine. If you were doing this for a gantry mill you would want the full voltage. Voltage is required for speed when you rapid out of the work. A small mill will not be making rapid moves for long distances like a gantry router. Save your money and use the existing drives and motors with light cuts for now. Once you have programed the part it could be runing while you are working on your other cnc project. Who cares if it takes twice as long to make the part if you are doing somthing else. I do not understand the need for speed in the hobby realm? Unless you are watching the paint dry, LOL, then by all means go spend the money on a Hass. My two cents!