PDA

View Full Version : My CNC conversion -homier mini



JFettig
02-22-2004, 03:00 PM
Hey guys, Im in the process of converting my mill, Im almost complete actually.
What I have is:
Homier mini mill
Gecko 201s
Japan Servo KP86SM2-002 Stepping Motor
2.35 VDC, 1.8 Degrees/Step
They are bipolar 2.5V @ 4.1 Amps

A power supply I made:
24v(12-0-12) transformer(1 or 2) 80v max 18,000uF capacitor, and bridge rectifiers.

At 24v I get around 30v after capacitated, at 36v I get 56v max after capacitor, Im affraid of even hooking up total 48v to it because my cap may 'splode. I really wanted to run these at 48v but Ill have to get another capacitor with a higher maximum and a voltage regulator.
So right now I have the 24v hooked up because 56v is close to the absolute maximum of my motors.

The motors are rated at 4.1A but I was told to run them at 2A because thats not over 67% of the rating. Should I have it at 3 or even 4amps?(set on my gecko 201s)

Heres some pictures of where Im at:
http://www.wc101.com/JFettig/mill/
Heres a short video, dont download it too many times, I might be short on bandwith.
http://jfettig.wc101.com/cncncbig.avi
*note* Yes I realize the Y is backwards :rolleyes:

Also I have a pully set I got made up, maximum of 9000rpm, I took the bottom bearing and spindle out of the head, and didnt have a flange to take the top bearing out without killing it, and to put it all back together I'll need to get ahold of a boaring bar and make some when I get my lathe unless someone else has another idea or could help me out with that.

http://www.wc101.com/JFettig/mill/1.jpg

http://www.wc101.com/JFettig/mill/2.jpg


http://www.wc101.com/JFettig/mill/3.jpg

http://www.wc101.com/JFettig/mill/5.jpg


Let me knwo what I should do,
Thanx
Jon

Mr.Chips
02-22-2004, 04:23 PM
Nice job. Like the use of an old PC case for the PS and controllers. I am doing the same thing.
Do you have a schematic of your PS?
Hager

Stevie
02-22-2004, 05:02 PM
Nice; did you get the steppers from Toronto surplus? I just ordered 3; have you chked the power of those steppers; I asked for the torque rating and she did not have anything to offer

BTW; love the vid:D

JFettig
02-22-2004, 05:11 PM
Heres a scematic. The voltages are what they should be, but Im getting 16v out of the 12v, 30v out of 24v, 56v out of 36, and it would be around 70+v out of the 48v.

http://www.wc101.com/JFettig/mill/PSscematic1.jpg
I just used my electronics knowledge to make it without drawing a scematic, but I just drew this one for people who are interested.

I actually ordered those steppers off of ebay, then a few days later I saw them at toronto! for cheaper!

I do not know the power, I would guess its 300+oz because its about the same if not more than the vexta 305s I beleve if I remember right.
-edit-
Can anyone tell me any info on the amperage? I want to know if I should be running them at 2, 3, or 4 amps.
I fixed the pic, I had the outputs wrong
Thanx:)


http://www.wc101.com/JFettig/mill/PSscematic1.jpg

Jon

Stevie
02-22-2004, 05:21 PM
I'm still in the planning stages for my fully built by me 3 axis cnc mill
But with $35 price tag i couldn't resist
I'll also get the servos that are listed for 9.95; but I'll have to add the US digital encoders

I want to try both setups

JFettig
02-25-2004, 11:24 PM
Im still waiting for my metal, onlinemetals didnt ship it for some reason, I got almost everything but that and another peice

I still need information on volts and amps of what I shoudl be running.

Thanx
Jon

CactusChip
02-26-2004, 12:48 AM
Hi Jon,

I have the KP86 steppers too, and I'm in the same situation as you are: Should I run at 2 or 4 amps? I have tried running one motor at 4 amps with my G201, and it didn't get too warm, but it was free running. I haven't tried any weights or anything to check the torque. If I could get away with 2 amps, then I can use my old 8A power supply and not have to buy the parts to build a "monster". I would like to keep enough torque to make these steppers worthwhile, though.

BTW, I'm using these to replace the old unipolar steppers/FET3 on my HF micro mill, hoping they would give me a little more speed than the 5"/min that I was getting before with my 125oz motors... I'll be watching this thread to see if someone else has worked with these motors and knows about the required current.

Billy

JFettig
02-26-2004, 07:44 AM
I dont know what kind of speed you will get with leadscrews, but with ballscrews I can get up over 60ipm I beleve. Im not 100% sure, Ill have to hook it up to my main pc with mach2 to see if itll read out for me. I can definately go well over 10 though:) and thats at 24v(around 30v)


Jon

Stevie
02-26-2004, 05:23 PM
my Japan Servo KP86SM2-002 Stepping Motor's arrived today; I thought they might be used take-offs; but no NIB's for sure; still in the man/ers box; great deal for sure
I've already updated my CAD drawing of the mill to NEMA34 sized drives; now a question; can anyone here tell me how to hook these up to a manual driver; i want to drive them like a manual jog on a full sized CNC Mill; it would be nice to have a multi switch to change the step increments; say 0.01 then 0.001 and finally 0.0001

buscht
02-26-2004, 06:00 PM
stevie, you can jog the motors using a program called TurboCNC. It has a jog screen that will allow you to do exactly what you want.

Also, let us know the OZ-in of those motors. It seems to me that they are more around 80 to 100 oz-in. but I am just guessing by comparing them to others on the Japan Servo website.
T

Stevie
02-26-2004, 06:05 PM
I think they might be bigger than that; here's a link to the size I've got http://www.microkinetics.com/34m315.htm

sorry; edit; forgot to add; the lathe I want to jog them with is going to be fully manual for a while; I just want to speed the main carrage down the bed with a stepper
The mill project I need a similar set-up; but this will be for pick-up; I really don't want a PC in my garage; so I want to make the cnc mill use floopies and I'll tool path in the house

JFettig
02-28-2004, 07:31 PM
A laptop would do ya good, thats what I am using, a p166 compaq.

I really would like to get some information on the current I should be putting through these motors.

Also, does anyone know of a good way to make some decent ballscrew covers? I need one for my z axis.


Jon

Stevie
02-28-2004, 07:43 PM
https://www.reidtool.com/store/store/listCategoriesAndProducts.asp?idCategory=9028
Here are baLL screw covers

JFettig
02-28-2004, 07:48 PM
Yeah, I was hoping to make my own, I dont have $30 a foot:)


Jon

cncadmin
03-26-2004, 10:32 PM
That is very exspensive for sure.

JFettig
03-26-2004, 10:47 PM
I got it all up and running today, I still need to make new pullies for the spindle drive so it has more torque, I am able to cut aluminum pretty well, I tried copper and it locked and snapped my 3/32" em pretty fast. (the motor protection thinger stopped it) I was cutting some with a 1/2" end mill, shallow cuts, no problem, Cut a little delrin, that went really well. Got part of my steam engine made.

Im working on the main body now, and the flywheel

Jon

cncadmin
03-26-2004, 11:12 PM
Need pictures!!!

JFettig
03-27-2004, 12:28 AM
Alrighty:)
Http://jfettig.wc101.com/cnc.jpg
one of my first parts:
Http://jfettig.wc101.com/keychain.jpg
a part I just whipped out
Http://jfettig.wc101.com/crank.jpg
its for my steam engine Im workin on. I already got the piston made and I made the cylinder earlier today.
Heres a pic of it between cuts in the cylinder(delrin) I made a shroud around the table that attaches to the X axis, thats a temp one, Im going to make a really nice one soon. itll be ready for flood coolant :drowning:
Http://jfettig.wc101.com/cnc1.jpg

Jon