Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: forrest on August 15, 2008, 05:07:04 PM

Title: dual x axis direct drive jumpy
Post by: forrest on August 15, 2008, 05:07:04 PM
I built a router with two direct drive stepper motors for the x axis. The machine is 10 feet long and 5 feet wide. I'm using Mach3 and a 4 axis driver from Mecntronis (easy cnc). I've set mach3 to use A axis as the slave axis of the x axis. The motors are using a timming belt systam and the dirive is direct so one revloution is 1.5 inches in the x direction. I've set it up and it cuts circles pokets and all that stuff pretty accurate but rough my y axis is an acme thread and runs about 4 reves per inch and seems smooth. The x axis is jumpy at low speed, you can hear it move it sounds like about a 30 40 herts pulse.

Is there any thing I can do to smooth this x axis out. on curves you can see each step the motor makes?
my thought is to make a couple of transmissions for the two motors so that each turns about 4 rev per in or so?
any thoughts would be appriciated.
Forrest
Title: Re: dual x axis direct drive jumpy
Post by: Overloaded on August 15, 2008, 05:25:25 PM
Reduction gearing or a microstepping driver.
RC
Title: Re: dual x axis direct drive jumpy
Post by: Hood on August 15, 2008, 05:29:49 PM
you got a link to your drives?
Hood
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 15, 2008, 05:35:02 PM
I'm not sure what you mean by link, physically connected motors or electronically connected or?
Title: Re: dual x axis direct drive jumpy
Post by: Hood on August 15, 2008, 05:37:36 PM
Sorry, I mean a link to the website of the makers. I have done a google and cant find any info on it.
Hood
Title: Re: dual x axis direct drive jumpy
Post by: uuccimi on August 15, 2008, 10:33:30 PM
I built a router with two direct drive stepper motors for the x axis. The machine is 10 feet long and 5 feet wide. I'm using Mach3 and a 4 axis driver from Mecntronis (easy cnc). I've set mach3 to use A axis as the slave axis of the x axis. The motors are using a timming belt systam and the dirive is direct so one revloution is 1.5 inches in the x direction. I've set it up and it cuts circles pokets and all that stuff pretty accurate but rough my y axis is an acme thread and runs about 4 reves per inch and seems smooth. The x axis is jumpy at low speed, you can hear it move it sounds like about a 30 40 herts pulse.

How you did connect the motors (wires wise) parallel o serial?

Is there any thing I can do to smooth this x axis out. on curves you can see each step the motor makes?
my thought is to make a couple of transmissions for the two motors so that each turns about 4 rev per in or so?
any thoughts would be appriciated.
Forrest
Title: Re: dual x axis direct drive jumpy
Post by: ostie01 on August 16, 2008, 02:18:13 AM
Hi, I think I have the same board, is they're pot on the board with test pins, you have to adjust each to about 5 volts(2 times the current of 2.5 amp)  for the current and about 2.5 volts for the others.

http://cgi.ebay.com/4-AXIS-CNC-ROUTER-OR-MILL-STEPPER-MOTOR-DRIVER-BOARD_W0QQitemZ330262172457QQihZ014QQcategoryZ78197QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Is it this board?.

http://www.easy-cnc.com/web/download/Manual4Axis(NEW).pdf
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 16, 2008, 12:05:59 PM
I'm not sure how to work with a Forum, I see I have 6 replies with questions I'll answer them all here??
Overloaded, It is a microstepping driver.
ostie01, yep thats her
uuccimi, parallel
hood, http://.easy-cnc.com
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 17, 2008, 06:20:12 PM
it's microstepping
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 17, 2008, 06:20:56 PM
it's easy-cnc
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 17, 2008, 06:21:21 PM
parallel
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 17, 2008, 06:24:33 PM
Sorry, I mean a link to the website of the makers. I have done a google and cant find any info on it.
Hood
it's easy-cnc
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 17, 2008, 06:25:26 PM
Reduction gearing or a microstepping driver.
RC

it's microstepping driver
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 17, 2008, 06:26:17 PM
Hi, I think I have the same board, is they're pot on the board with test pins, you have to adjust each to about 5 volts(2 times the current of 2.5 amp) for the current and about 2.5 volts for the others.

http://cgi.ebay.com/4-AXIS-CNC-ROUTER-OR-MILL-STEPPER-MOTOR-DRIVER-BOARD_W0QQitemZ330262172457QQihZ014QQcategoryZ78197QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Is it this board?. yes this is it


http://www.easy-cnc.com/web/download/Manual4Axis(NEW).pdf
Title: Re: dual x axis direct drive jumpy
Post by: Hood on August 17, 2008, 06:31:58 PM
Have you adjusted the pot as oastie said?
Do your axis move the correct distance when you MDI a move?
Hood
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 19, 2008, 02:26:45 PM
sep volts and amps are good, measurments are repetable to .oo1 over ten or more repetions
Title: Re: dual x axis direct drive jumpy
Post by: Hood on August 19, 2008, 03:52:09 PM
Looks like gearing maybe the only way then, what are your steps per unit set at and is this imperial or metric you are using?
Hood
Title: Re: dual x axis direct drive jumpy
Post by: forrest on August 19, 2008, 05:17:14 PM
units a imperial, steps per is a ripping 802.8114176 vel is 5 accel is 5 the driver is set to 1/8. Your conclusion is same as mine, if I make a 4:1 transmission it'l be very close to the acme im using on the y axis. Plus I can use the machine to make most of the parts now. Beats drilling sawing and lots of file work. Wow I just noticed your a Scott, wow isn't the internet a neat thing?
Oh, and thanks for all the ideas and thoughts
Title: Re: dual x axis direct drive jumpy
Post by: Hood on August 19, 2008, 05:35:09 PM
Your motor will do 1 turn for every 1600 pulses so the carriage moves almost 2 inch for each rev of the motor? Can you get a smaller wheel on the motor?

Well almost, I am a Scot ;)
No probs, like to help when I can :)

Hood
Title: Re: dual x axis direct drive jumpy
Post by: Sam on August 20, 2008, 02:18:50 AM
 ;D picturing Mario headbanging with a kilt on.
Title: Re: dual x axis direct drive jumpy
Post by: Dzackman on August 28, 2008, 12:58:41 PM
   I to am having the same jumpy problem at low speeds with my X axis using the 4 axis Mechatronics board.
I switched from a Xylotex 4 axis board that ran fine until a lack of proper grounding on my plasma cutter messed it up some how.
The Mechatronics board has a lot of good features so I’m hoping some how we can figure this out. I look forward to watching this forum post

Dzackman
Title: Re: dual x axis direct drive jumpy
Post by: Dzackman on August 29, 2008, 06:39:07 AM
Solved my problem, it was a loose wire. For anyone else with the motor jitters at low speed, check and check again your wiring.

Dzackman