Good morning,

I have read a lot on backlash and have no first hand experiance with it.

I was under the impression that I could program out the backlash with Mech 3. Is my thinking correct or not?

Or since I am in the just beging should I just pull the 36:1 gear box off the motor and go directly to timing belts in the same reduction range?

Al

You can use the backlash compensation built into Mach to remove it. What it does is rapidly move in the opposite direction the amount you tell it before moving the rest of the axes. It is a little nerve racking to watch and will add time to the program. It would be better in my opinion to shoot for zero backlash and move on from there. I have removed and modified the gearbox motors to work on a belt drive but this is not an easy task. I can be done by not easily. The motor shaft is ground with a spline to adapt to the gearbox. Stepper shafts are extremely hard. I had a choice of grinding the stepper shaft down to remove the spline or use the spline to cut or broach the aluminum pulley. I opted for the broach method and used Loctite 480 retaining compound. But to press the pulley on it has to be controlled and a special pressing block must be made to hold the stepper back side of the shaft from moving inside the motor so you do not damage it well applying the massive force it requires to seat the pulley.

If the motor is unopened and unused, you may be able to do an exchange. You could try it and see how back the backlash is and if you can live with it. Backlash is a funny thing, depending on what you are doing it my not affect you. Wood is forgiving that way as it moves greatly with small amounts of temperature and humidity.

Al,
Backlash sucks when it affects you, I can tell you that much.

Hi all it been almost 7 years since i finished building my machine and have had any problems with my machine till now.

The problem is my x drive motor it runs fine then it chatters and louses steps then it runs fine again. I have a new PK296A2A-SG7.2 motor and plan to replace it.

Many moons ago I read that if you are wired to half coil you are only using half of the motor and should there be a problem you can change to another winding. Am I correct and or was i dreaming. I have looked and can no longer find the thread i believed to have read.

Thanks Al

Also if i jog it slow it is fine If I fast jog it acts up Checked all wiring it's fine . I also ordered a new 203v

Found problem. One of the wires supplying the x drive in the wire e chain broke thru the insulation and was occasionally shorting to the outer shield of the cable. Replaced cable no problems in the first three hours of operation.

Humm...interesting, what brand cable is it ( was it ?!)
Later

This was used cable when i put it in. Now I changed all stepper wires with Southwire from Automation Direct Item code is MCTC-18-45-1

The first time that happened to me, on my other router. I spent a few hours scratching my head. It is not an uncommon problem. Especially, if you use your machine.

I gets used daily for almost 7 years now

Al what are you cutting mostly signs?, a spare wire would be a good diagnostic tool instead of searching for the break.I will be using mic cable until mine (not completed) earns its keep, and expecting to have issues with it.

i cut all kinds of stuff from full table pieced. A lot custom one off items to several hundreds of the same.

I just bought a whole reel of wire for spare parts.

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Keyaki is the preferred wood for traditional Japanese tables, laquered to a shine that blinds. The wolod also is pretty expensive and getting scarcer every year. I have 5 or 6 slabs stashed away but havent found the time to work on them yet

Today my x axis stopped moving and the x is fine. I am using oriental motors and gecko drivers. The program Mech3 shows it is stepping on the screen.Should I try to change the gecko or the motor first . I have both. Or is there a better way to locate the problem.

Thanks Al

I had a very similar story on my plasma machine under Mach3. The machine is more than 8 years old today. Everything was working fine. Then it started to malfunction. Then the machine stopped working. I had to take everything apart.

Turned out to be a simple DB9-DB9 cable. One wire had fallen off in it! Only 1 !!! And the machine went down. Replacing the cable solved the problem.

I think you need to check the LPT cable, every wire. And everything around the LPT connectors.

Will look at that . Everything except the x axis it just keeps carving away only in a straight line.

I'm sure. You can do it!

I have had this single axis problem with my CNC before and what solved the issue for me is tightening the screw/wire connections at the Gecko. I have found that at the beginning of every cold season, I will occasionally have this intermittent problem and going through the box and tightening everything seems to solve the issue.

Unplugged parrell cable from computer and controller cleaned and reinstalled reinstalled . Only had time to run a small project everything ran good. Will run large rojec this week will keep my fingers crossed.

Thanks Al