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4 Axis Board - TB6560

Posted: Mon Mar 26, 2012 6:32 pm
by mhackney
After grappling with the 3 Axis Board/EasyStepper for too long, I decided to try one of the Chinese 4 Axis boards. It came in on Friday and I spent some time doing the conversion. I now have lots of torque on my extruder (A axis). I did have to perform the "opto isolator-ectomy with staple jumper replacement" but that was the only mod the board needed. The pin configuration is a bit different too. I'll post my Mach config after I do a recalibration.

One thing I did discover; now that I have a lot more power on the extruder it is not necessary to have a really hot barely. I was going for 425° but with fluctuations that might be a bit higher. I did get some blow out through the resistor openings along with a melted and mushroomed Teflon tube end. Lowering the temperature seems to prevent the tube from distorting and blow out occurring.

Cheers,
Michael

Re: 4 Axis Board - TB6560

Posted: Mon Mar 26, 2012 7:47 pm
by Dave_Sohlstrom
After my frustration level peeked with the three axis board and a Big Easy board i went with Gecko drives G540 4 axis unit. The price is higher than the boards coming out of China but well worth the money. No tweeking or mods needed just wire it up and go. I did have to use a power supply with higher voltage. In my case 26VDC.

Re: 4 Axis Board - TB6560

Posted: Tue Mar 27, 2012 8:28 am
by mhackney
The G540 is a fantastic unit! I use 2 of them on machines I've converted (an X2 mill and a lathe). I wanted to try the low cost option for the H-1 though "just because"!

cheers,
Michael

Re: 4 Axis Board - TB6560

Posted: Tue Mar 27, 2012 10:52 am
by Dave_Sohlstrom
The low cost option is good.

Re: 4 Axis Board - TB6560

Posted: Wed Mar 28, 2012 10:14 am
by cquinby
Michael,

I had issues with the easy driver also at the beginning. Constant stalling just like you described. It didn't matter if I turned the pot up or down, it would just stall out. I found some interesting issues and it wasn't the easy driver.

At first I noticed the feed roller slipping so I cranked down the bolt and nut, well this solved the slipping problem but then the missed steps started! I messed around with the easy driver trying to see if it was a power delivery issue and constantly adjusting the tightness of the nut and bolt running thru the feed roller. This was a lost cause as it would work fine then start slipping again, tighten and then miss steps.

After about a week of tweaking I tried something new. I took the two gears off and found that the inner gear was just a bit too tight against the outer gear not allowing for the drive to reduce the gear ratio. I separated the two gears just enough so they didn't touch, put the assembly back together and bang, it worked perfect!!! I have not had a issue since. I also have the easy driver set to maybe 1/2 on the power output pot.

Now I am looking at the heat dissipation from the steppers. I can not believe how hot these things are getting compared to my CNC mill. I run Keling Digital drivers (5056D) on that machine and I tell you, the steppers are just above room temp after hours of running. I guess those drivers are the bomb to say the least. Just wish they made a smaller driver at a reasonable price as I would change out in a heart-beat. The other nice thing about the digital drivers is they are supper quiet. I get very little stepper noise on the mill.

Anyway, I'm wondering if folks are having issues with the extruder stepper due to the gears being pushed together. Just a thought...

Re: 4 Axis Board - TB6560

Posted: Wed Mar 28, 2012 11:02 am
by mhackney
I went through the exact same steps as you! Including the part about the gears. I actually used a split ring (1/4") washer that I flattened in between the gears. It is the perfect size to press against the bearing inner race. For me, doing all of this stuff got it to just b.a.r.e.l.y work. But I would still get missed steps on the stepper at inopportune times. I got frustrated and swapped out to the 4 axis card and it is like night and day. The A stepper has so much torque now that it can pull the filament off the spool with no problem and I have not had any printing problems.

cheers,
Michael

Re: 4 Axis Board - TB6560

Posted: Sun Jun 24, 2012 10:47 pm
by JTCUSTOMS
Might be a silly question but can one run 2 motors in parallel of of one axis on this board?, I am printing parts for a prusa for a friend and he wants to use this board to save some cash on the build.

Re: 4 Axis Board - TB6560

Posted: Mon Jun 25, 2012 12:14 am
by michaellatif
JTCUSTOMS wrote:Might be a silly question but can one run 2 motors in parallel of of one axis on this board?, I am printing parts for a prusa for a friend and he wants to use this board to save some cash on the build.
Yes, the TB6560 can handle any number of motors in parallel as long as you stay below the max current draw the chip handles (3.5A?).

Re: 4 Axis Board - TB6560

Posted: Mon Jun 25, 2012 11:25 pm
by JTCUSTOMS
Would series be a better option for this instance?
ie: 2 motors for the Z axis.
There is not a need for a fast Z on these little printers.

Re: 4 Axis Board - TB6560

Posted: Tue Jun 26, 2012 10:38 am
by michaellatif
I considered running two Z motors on my H-1, but I decided against it. The current setup with belt and tension works out well enough and having to find small enough belts to make two motors work is not worth the hassle.

Re: 4 Axis Board - TB6560

Posted: Tue Jun 26, 2012 9:34 pm
by JTCUSTOMS
this isn't for the H1, its for a mendelmax. I am VERY happy with the performance of the H1 so far. I did not run it in stock trim at all, so I cant really compare after all the mods I did.
But I have about 3 spools through mine so far and it has been rock solid.
Love the lights out machine. Start it and walk away.

Re: 4 Axis Board - TB6560

Posted: Tue Jun 26, 2012 9:43 pm
by michaellatif
Ah, I just noticed you said 'series'. I have never wired motors in series, but it should be doable. I would watch current draw, in series it will be less because of higher coil resistance, so maybe compensate with higher voltage?? Wild guess here.

Re: 4 Axis Board - TB6560

Posted: Tue Jun 26, 2012 10:59 pm
by JTCUSTOMS
I thought about the higher voltage but maybe just slowing the velocity down on the Z will allow him to use a 12v power supply (he already has one).
I guess there is only one way to find out ;)
I am running out of filament gonna order some more tonight.
Haven't tried any PLA yet just been running ABS maybe I will give it a shot.

Re: 4 Axis Board - TB6560

Posted: Wed Jun 27, 2012 2:43 pm
by drkow
single motor z axis gives you the advantage of being able to manually jog both sides at the same time at the start of the print, I do this all the time to get my first layer height just right.

you should wire the motors in series like they do on the reprap RAMPS setups. The z-axis doesn't need much torque so you shouldn't need to mess with volts/amps unless it's skipping.