Sourcing Makerbot parts for Mendel

I have now printed a complete set of Mendel parts in Green Ultimachine PLA. The parts look amazing! I have two Makerbot Cupcake CNCs. I plan on sourcing many parts from the Makerbot to make a Mendel. Is it feasible to use the pulleys and steppers then simply source longer belts? I know this isnt in the spirit of Reprap, but i believe that is i use the Makerbot drive system, i should be able to theoretically use the same firmware from the Makerbot Mother board and extruder. The only difference is now the system has a much larger freedom of motion.

Could someone with some experiance with this give some tips or advice? Thank you!

For your viewing Pleasure
[www.Flickr.com]

That is pretty. It almost looks organic.

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repraplogphase.blogspot.com

I've also made my Mendel parts on a Makerbot (in white/natural ABS though) and am using/hacking the Makerbot firmware for the Mendel.

You don't need to use Makerbot pulleys just because you want to use their firmware. ReplicatorG configures your RepRap properly from its machine.xml, and I've made the following entry to machines.xml to make it work. I took the values for steps/mm on the axes right from the Mendel FiveD firmware, so they are correct (it also works fine).

Just append this to the "machines" element in your machines.xml, and you can use the Makerbot firmware with the proper printed Mendel pulleys and the 5mm belts.

<machine>
	<name>RepRap Mendel</name>
	<geometry type="cartesian">
		<axis id="x" length="405" maxfeedrate="10000" scale="10.047"/> 
		<axis id="y" length="405" maxfeedrate="10000" scale="10.047"/>
		<!-- Z uses the same pulley, but is geared down pretty hard -->
		<axis id="z" length="365" maxfeedrate="150" scale="833.398"/>
	</geometry>
	<tools>
		<tool name="Mendel Stepper Extruder" type="extruder" material="abs" motor="true" floodcoolant="false" mistcoolant="false" fan="true" valve="false" collet="false" heater="true" motor_steps="3200"/>
	</tools>
	<clamps></clamps>
	<driver name="sanguino3g">
		<!-- optional, defaults to first serial port found.    <portname>COM1</portname> -->
		<!-- required: we need 8 bit and 38400 baud. -->
		<rate>38400</rate>
		<parity>8</parity>
		<!-- optional, defaults to 1.                          <databits>1</databits> -->
		<!-- optional, defaults to N.                          <stopbits>N</stopbits> -->
		<debuglevel>0</debuglevel>
	</driver>
	<warmup>
	</warmup>
	<cooldown>
(Turn off steppers after a build.)
M18
	</cooldown>
</machine>

Oh, and as an additional tip, you might want to print something like this for your pulleys instead: [www.thingiverse.com] - Filing flats into your motor shafts sucks big time, so using screw-on pulleys will save you *a lot* of headache. I'm using a pretty similar design (but with 3 screws instead of just 1), and it works extremely well and was much easier to install.

One more thing: If you're getting your steppers from Makerbot, be aware that their NEMA17 stepper will not have enough torque for the stepper-driven extruder. The axes will work fine, but not the extruder. I'm using the Zapp Automation 4.5kg/cm NEMA17 steppers, which I'm driving with a Pololu stepper board for the extruder. It has excellent torque and performs very well this way. The Makerbot NEMA17 is way too weak, especially if you intend to drive it directly from the Extruder Controller board with this awkward "we're using H-bridges to drive a stepper" hack.

Edited 2 time(s). Last edit at 04/01/2010 07:55AM by gkaindl.

Thank you for the advise and comments! I am excited to announce that i took the plunge! I took the jump and went ahead and sourced Makerbot parts to make a Green Mendel! I understand that the Nema17 steppers from Makerbot wont work directly as extruder motors, however there are already ways around that with 'geared' extruders. This way you can use relatively low torque steppers and still have high torque output. Since the stepper will not need speed its ok to gear it down.

Green Mendel! Its better in everyway! Just kidding. So far the axis seem to act same as Makerbot and i didnt have to create additional files. Although that information is very useful when the day comes that i will want to make a Mendel with printed pulleys.

Ok. I made a mistake. The Makerbot belts are so flexible and flimsy that they can become lodged between wall and bearing on the idlers. This causes a ton of friction and your Z axis will not function properly. More on this as i fix it. So far X and Y are beautiful though

GKaindl-

Hey I've been working with Cid lately on our Mendels together and I've entered the specified settings you gave for the machines.xml file you gave. It revealed the RPM field in the RepG control panel and the stepper can spin for a little bit, but then begins to skip steps and freeze up/get the jitters. Any ideas of what I might not be doing correctly?

I started with all makerbot stuff on my mendel and have since had to replace almost everything due to low torque on the motors and not being able to run the stepper extruder system using it. but it is a good rout to start.

I'm using Makerbot electronics and steppers on my Mendel, and it runs at 50 mm/s no problem. One thing I did change was the extruder though - I use a 5 kg*cm Kysan stepper for that, and my geared extruder.

Wade

"Green" with envy. Thanks for posting your machines.xml. I have a TechZone LaserCut Mendel assembled and working, without a properly configured machines.xml file. My attempts at parts and calibration testing pieces form Thingiverse are failures so far. I used SAE 5/16" Z-axis lead screws and need to continue calibration. All of my electronics and motors are MakerBot's and I'm using their Plastruder for now. XYZ torques are ok. I find that the extruder tip hits hardened ABS wisps and then loses steps. Much to learn. . .

We have made a Mendel using the Makerbot electronics. We are using the RelpicatorG software in order to have the environment for both the Mendel and Makerbot.

I have tryed to change the firmware in order to run a stepper motor for the extruder. I found some advice but it seems to be for an old version. Compiling and upload was OK (i think). Any ideas ?

The ATX power will be below the white plate.

Hey Wade (I am assuming you are the same wade as designer of wade extruder? If so great extruder, nice job)

I am using the largely the same set up as you, using makerbot boards, Mendel and using the replicatorG software.

I have set up the machine and all works fine within the control panel. I am using a nema17 which seems to be extruding ok at 35rpm with a drilled out 0.9mm extruder nozzle. Was having trouble with the .35, which is probably due to the available torque on the nema17.

I have made the changes within the Sanguino software and updated the firmware, running a separate stepper driver off the extruder board.

Have installed the stepify.py to adjust the Gcode.

A couple of questions

1. Do you use the rpmify plugin for skienforge?

I am having trouble with printing (no printing), as the stepify addon in the Gcode profile does not display the whole page and therefore I cannot turn this on and save. (I have tried counting through the steps and tabbing to where the save button should be but the tabs do not go through these buttons for some reason, tested with other preferences). Not sure how to get around this without going to another computer with a bigger screen.

I have tried running this directly in the Skeinforge standalone 006, but cannot adjust, it just opens an empty txt dialogue.

2. Are you able to post your machine settings? I am a newbie, despite having read through everything available I am still having trouble

3. I have tried to get on to Kysan's website to purchase a 5kg/cm Nema 17, but they only accept purchases over $100, did you purchase yours from elsewhere?

Any help would be much appreciated, I have spent a huge amount of time building the thing (link to blog below), with my students and I am so close but still cannot print - I need to get the machine running for an exhibition that I have in October, would be nice to see all the hard work pay off.

[reprapstudio.wikispaces.com]

best

James
Australia

Bristol UK. Any mendeler colleague available in this area for reasonably 'cheap' parts for Mendel starter?

Also would like complete CAD file for Reprap Mendel II or III if anyone has.
Autocad or Archicad preferable but can probably handle most formats.
Regards to all
FJW

I have updated my extruder firmware. I am in the process of altering my machines.xml code as stated in the instructions (Configuration section of [wiki.makerbot.com]). From my inspection, the last two releases of ReplicatorG did not have a machines.xml file. Where do I insert the indicated code and how do I get ReplicatorG to use Skeinforge 35 as stated in the Configuration section (as before).

Are you saying the driver is too weak or the motor?