MakerBot Industries

So I need to upgrade X,Y and Z but not the stepstruder, plus ditch the driver boards? Looks like I got into this at the wrong time, I mean how many upgrades will we have to do to make this reliable? I think the stepstruder has been the greatest upgrade ever, but this thing is turning into a money pit. Can you remember if you could get those RC values dialed in? I was printing happily for several months before the failure, no skips and nice prints, I'd like to get the thing going again with as little money as possible.
Thanks.

I agree that the Pololu boards are far superior. The original boards are far to complex for the job at hand.

I do have question for Jetguy, I am still running my Pololu boards at 1/8 step. Aside from the jumper setting on the Pololu board what software configuration changes need to be made? Is it in the machine file?

Thanks,
Ron Wensley

Anyone out there able to adjust RC1 and RC2 to the proper values? Were the pots maxed out clockwise?

Tom, the reason they are likely maxed is the stepper is in enabled mode-you must ensure they are not enabled from the control panel or else you cannot adjust the RC values! Easy tip is to just hit reset on the motherboard and they will diasable by default.

As for machine.xml changes here you guys go. ALL you do is double the steps per mm—that's what 1/16th vs 1/8th is. The other numbers are there for reference only showing you the calculation used to get that number. Remember the motor is 200 steps per rotation at full step mode, so multiply that by the divisor (200*16 would be 3200 steps) times the radius of the pulley gives you the distance per rotation.
Here is my code and notice I have 1/16th on x, y and z on this bot. If you only use x and y at 1/16th step then ONLY change those lines. Also, the length listed is what determines the bounding box in rep-g but it's only visual as a guide. You can excede the size but again just know that you should match it to your z hieght from the claibration so you don't try to scale something taller or bigger than what the mechanics can reach.

<name>Thingomatic w/ ABP and Stepstruder MK6 1/16step</name>
        <geometry type="cartesian">
            <!-- different pulleys on X and Y axii -->
            <axis id="x" length="98" maxfeedrate="4000" stepspermm="94.139704" endstops="min"/>  <!-- Pulley dia: 10.82mm / 1/16 step = 1/(10.82 * pi / 3200) -->
            <axis id="y" length="98" maxfeedrate="4000" stepspermm="94.139704" endstops="min"/>  <!-- Pulley dia: 10.82mm / 1/16 step = 1/(10.82 * pi / 3200) -->
            <axis id="z" length="106" maxfeedrate="1000" stepspermm="400" endstops="max"/> <!-- TR-8x8 Z axis = 1/(8/3200) -->
            <axis id="a" length="100000" maxfeedrate="1600" stepspermm="50.235478806907409" endstops="none"/> <!-- stepspermm is incoming filament length, 127 is ca. 4 RPM, 1600 ca. 50 RPM -->
        </geometry>
        <tools>
            <tool name="Stepstruder MK6" type="extruder" material="abs" motor="true" heatedplatform="true" automatedplatform="true" motor_steps="1600" default_rpm="1.98" heater="true" stepper_axis="a"/>
        </tools>
        <clamps></clamps>
        <driver name="makerbot4ga">
            <!-- optional: <portname>COM1</portname> -->
            <rate>115200</rate>
        </driver>
        <warmup>
        </warmup>
        <cooldown>
(Turn off steppers after a build.)
M18
        </cooldown>
    </machine>

I can enable and disable from the control panel, they are disabled, motor LEDs are out. Now what?

If it's still way out of range or won't adjust, I assume they are shot, but since I don't have a bad one, I cannot verify that behavior. Pololu's are soo much better I would have given up and ordered them the first time. It's less than $40 for 3 of them and you can get a stripboard at radioshack and a couple of resistors and be running in about an hour with 3 2.2 k resistors (for the mode pullups), a 7805, to power the logic voltage, and mayby a couple of filter caps from a junk drawer. Heck, desolder the parts you need of the bad stepper drivers (5 volt reg, 2 caps, headers).

All I'm saying is a better driver for 3 axis, that is the same price as one bad driver that you said failed twice.

I've got the pololu's in a drawer, I just need to make some carrier boards. I just don't get it, this is such a light weight setup, why are there so many problems?

I'm thinking about trying out the 4 stepper driver from Sparkfun. It's only $65 and would work perfectly for our application on the new motors which are 0.86 amp steppers.
I know some guys on the Sparkfun page were saying the board is weak thermally over 1 amp, but repraps are using the larger and longer NEMA17s rated at 1.5 to 1.6 amps VS the Makerbot motors of 0.4 and new ).86 Amp motors. The baord is fine with no heatsinks at 1 amp each so no worries for x, y or z. 4 Drivers on one board is nice! Easy to wire up with the ribbon cable and it takes a single voltage source. It might not handle the MK6 without a heatsink on that chip but even then, it's not a bad deal. 4 MBI drivers is $160 on paper VS a single $65 board which provides quieter stepping and has less pots to adjust?

http://www.sparkfun.com/products/10507

Also, wiring up a Pololu is so easy. for 1/16th step, connect all three MS (mode pins) through a 2.2k to the 5 volt logic level. The V mot goes to 12volts, and the VDD is logic 5 volts, short the sleep pins together leaving you with connecting step, dir, and enable towards the motherboard.

I've just etched some pscc15 carrier boards which I've modified to single sided. Just need to drill them and I've got some drop in replacements for the MBI drivers.
The Sparkfun boards look interesting, except that if one driver fries your back to spending > $65 to get your bot going again.

I've yet to damage a 4983 yet on any of my bots-even the acrylic one that you would expect static to be a problem in. I'd say it's a safe bet.

That is just the question and result I was going to drop. How often do you fry a chip? If these things (ICs) were that prone to failure all our world would be in the trashcan with other burned out components.

Remember - if you are old enough - the days of - "Oh you can't have an amp in with the tuner." and "You can't have the tuner include an equalizer. You have to have all separates. They just do not work that way where you can have all in one stereos."

What about a phone with a camera, with a texting device, with a word processor, with …. You get the picture.

We have to not BOX ourselves in.

I've gone through four v3.3 stepper boards, they all stopped recognizing the mode switch. Just about every time it was after a static discharge touching the bot. All of the electronics were changed out once and I thought the problem was cured. The last board cost me ~$45 because they would not warranty it. They say the definition of insanity is doing the same thing over and over expecting a different result, so I'm going to try these Pololus. I'd sure like to get to the bottom of what's really going on, but it's costing me too much.

Yes, I'm 50, and yes I agree, it's just that I'd rather have a board that takes a $13 plug-in part to get it going. I think if these Pololus work out for me I'll make up the four in one board; the Pololus are still modular.

I've got some Pololu carrier boards made up, can anyone tell me how to set the current limiter for the older ToM stepper motors?
Thanks.

I'm amazed at the amount of people having problems with the stepper drivers 3.3s. I will not dispute the fact that the Pololu drivers are hands down better. However I dropped my 3.3 drivers in tuned them and never touched them again and have had no problems on a bot that has basically been running none stop since I started printing reliably.

I'm not always as diligent as I should be when I'm handling circuitry I will say when I was doing the cabling in my bot and installing the electronics I did not handle them in any special way.

I'd say if you have gone through 4 its time to give up on them and just go the Pololu route. There simpler and give you more options.

Well, the old motors will never microstep properly no matter what as the inductance and resistance are too high. SO-any value would work-as the motors are self current limiting.

Experience says around a 1/4 turn is the "sweet" spot. The way I do it is enable the motor and turn the current all the way down until the motor spins by hand, then increase the current slowly until it locks. Sound wise, there will be a squeel and then just a tiny turn more it goes away. That's the spot you are looking for.

And look, this is no offense to your age but due to the frequency-you might not hear the squeel-you need somebody young there to verify.

Awesome, thanks for the info.
Tom

Already did it, another good suggestion on Ed Nisley's site.
Tom

It only happened the winter before last when we had unusually cold weather and very dry air and my wife bought me new slippers for Christmas. I solved it by fitting an earth band to the slippers!

It never did any lasting damage to the drivers and they have been running 24/7 for well over a year now. The power LED did go dim though indicating the regulator was shutting down, so I have no doubt they would have died if they were directly connected to the PC supply and probably with a 1A regulator as well. I don't know why MB moved from 78L05 to 7805.

Ok, I'm going to install 78L05's, maybe my steppers will last longer. Thanks.
Tom