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View Full Version : A new stepper drive, up to 6 amps $44



ibewgypsie
06-08-2004, 12:35 PM
I bought a stepper drive off ebay. $44.??
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3817622218&sspagename=STRK%3AMEWN%3AIT&rd=1
It has onboard chopper, it is a unipolar design and not a bipolar. (only pushes * don't push pull) and can use 5,6,8 wire motors.

I am putting this one on my indexer on my mill. I am robbing the rutex/servo for another purpose.
If my pride would let me a bipolar gecko probably would be better at slightly more cost, but if I bought another and it died from mysterious reasons the Scottish blood in my veins would boil. (they die if you run them wide open)

It looks to work just fine for a small motor.

ANyone wanting to play with steppers, this is not a real bad deal. You could build a 3 axis machine to work, not be as fast or powerful as a high dollar one, but, imagine $200 in a machines cnc controls. You can hook a parallel port directly to the ttl step logic inputs.

Off to the shop to install this puppy.

David

John Stevenson
06-08-2004, 12:48 PM
IBEW,
What motor are you fitting on your indexer?

John S.

ibewgypsie
06-08-2004, 01:02 PM
I have several old Vexta motors, 8 wire. I have already built a mount.

I think they are about 200 oz.. not sure.. no nameplate specs. I have a 4:l belt ratio with the internal worm drive on the indexer. Final steps per rev will have to be figured out...

I have a dozen or so harley wheels to cut.. again.. I position them and cut them in quadrants. I don't have the fancy Jessie James software.. HA.. just some home brewed stuff.

Last time I tried this I lost a passel of geckos with a wheel on the table. I gave the wheel away. I was so disgusted with my cnc I started to get rid of it too..

I keep expecting to see a mushroom cloud, everything is working so great.
I guess the Larken drives, Mach2, and rewire to EMC I/O spec fixed everything to operate as designed. I have not changed the motors/drives wiring since the gecko fiasco, just added some inputs and outputs. I have I/O reserved for this, just remove the Rutex and add the drive step/logic.

I am waiting on the FLood coolant also, it is in the mail. I'll rig the 35 gallon barrel and lines this evening.

Little bites, chew slowly, that is how you eat a elephant... if you don't like the taste it leaves in your mouth, next time start at the other end first..

I ain't made a nickel this week.. ebay sucks.

David.

John Stevenson
06-11-2004, 06:46 AM
Ibew,
How about an update on that drive?
Looks interesting for a mid sized unit.

Over here Gecko's are 120 - 130 UKP,
on current exchange rate thats $218 - $236
Buying direct from Gecko's is out as they attract import duty.
One way round is to buy them and have them shipped to someone in the states, then shipped over private as a 'gift'
This way you get to save loadsa$$$$$

These boards off ebay at $44 works out to us at 24 UKP which is very cheap and well worth having some shipped over.

John S.

ibewgypsie
06-11-2004, 07:51 AM
John: I got distracted by something shiny.

Stepper drive, transformer, bridge is laying on my machine.

I have already mounted the motor on the indexer, not the best I have ever done but it will work for a test. I am running a exposed belt to the xl gear I have on the shaft. One unsupervised chip and "ohh crap".

I slept all night last night for the first time in months. WHew, I am ready for something. Drinking some Columbian coffee right now to get charged up.

I got three pages of shop-improvement jobs on the door. Each lil bite is another item gone toward happiness (yesterday was a permenant airline throughout shop). I am happier now then ever before in my life. I have a cnc santa-claus machine, a real good lathe, tubing, sheet and bar benders, cutters, I still don't have a ironworker but that is coming too with the press. (leaning up against wall unassembled)

The very large shaper, well I am motorizing the bed on it. I brought home several gearboxes, It had a auto-transmission and 3 phase motor on it. I want a hydraulic motor with speed control. I was going toward a lawnmower hydrostat, but.. Hyd Motor is on it's way. Until then, did you know the bed on one of them 8,000+ pound machines won't move when you bolt a rod-flatbar bender on them? It might become the next best worktable there. I cranked the shaper ram all the way back out of the way it has a 2foot table. Behind it, between the ram and the lathe is the "dangerous" spot in the shop. If I ever forget and get in there, oops.. gone gone, need a inheritor of the shop.
I am wanting to use the shaper to build ways for home-built-to-sell machines. Looking at the Chinese market it will not take much to make a lot better machine. A chunk of heavy I-beam trued tempered an quenched would make a better machine then what I see available.
I'd like to see "all" home shop machinists as happy as I am right now. Poor quality machines just make long hours invested an disaster-unhappiness as a end result. I'd like to see quality railroad models made like "used to be made on unimats" Nothing out there for sale I know of.

JOHN, if you need anything forwarded/relabeled and shipped to you let me know ahead of time. Mike or I will be around. AS long as it is not drugs, ha ha.. There are some bargains here, and some there. I go to the post office about 4 times a week.

perhaps the stepper should be the first item today... ( now 2 cups of wind em up coffee...)

David

[This message has been edited by ibewgypsie (edited 06-11-2004).]

John Stevenson
06-11-2004, 08:26 AM
<font face="Verdana, Arial" size="2">Originally posted by ibewgypsie:
John: I got distracted by something shiny.
</font>

ROTFLMAO
That cracked me up, just read the first line and couldn't stop laughing, not even read the rest of the post yet.

This has got to be the best group out for home shop guys.
Think about it, most are Stateside but the rest are all over the world.
We come from different levels of skill, life and means yet joined by a common bond.

There is the odd harsh word, very odd but by and large everyone on this groups gets on with one another, even Alistair is included at times, http://bbs.homeshopmachinist.net//biggrin.gif if he's good.

It's all about sharing be it tips, techniques, experiances or humour [ thanks IBEW, or should that be Magpie Dave, http://bbs.homeshopmachinist.net//biggrin.gif still smiling over this one http://bbs.homeshopmachinist.net//biggrin.gif]

It can probably be summed up in one word, Belonging.

Thanks Guys and Girls.

John S.

JimH
06-11-2004, 04:13 PM
David,
I have been looking into CNC'ing a mill for a while and all but settled on Gecko drives. Can you elaborate on the problem you had with yours?

As well as a follow up on how the new drive works out?

Thanks,
Jim

ibewgypsie
06-11-2004, 04:26 PM
JimH, at the thought of upsetting everyone again by harping on a old subject.. I don wanna. but,

previous posts. http://bbs.homeshopmachinist.net//Forum1/HTML/002844.html
http://bbs.homeshopmachinist.net//Forum1/HTML/002967.html

Problems looked to be heat related. The pcb inside the gecko holds the Mosfet against the anodized heat sink plate, you must bolt it to a larger heat sink and fan cool them. BUT, if the pinch of the pcb and the backplate on the gecko are not tight with the mosfets laying down flat, they burn up. Some pentium heat sinks are just the right size to bolt to them, Mariss should sell them as a option.

FOR smaller motors I recomend the gecko, for nema 42s I don't. They are a good drive for the price. Although some people do run them on thier mills, it makes them underpowered to MY opinion. My mill is running 8 amps, there is lots of different motors that came on the mills thou and you have to research that. mine is a old 1976 model.

If I had it to do over, instead of the Larken drives, I'd put Rutex servos on it. 5x1 ratio. if you are there you ain't that much further away.

I have not had any trouble since the replacement and rewire with the drives. I did replace one bridge, there is better ones and I'd have to look to see which I have in there.

Mariss of Gecko did offer to purchase back all my drives, I had already sold them on ebay or trashed them. He is a nice guy, I just won't purchase anything else from him cause of my pride.

FOR a application like this indexer, the gecko would have been perfect, running a 24vdc transformer, capacitor doubling would bump it to 36 vdc, it would have ran probably forever if nor pushed at it's limits.
IT is a bipolar drive, the unipolar does not have near the speed or power.

David

[This message has been edited by ibewgypsie (edited 06-11-2004).]