Questions About DC42 Kossel.

Having built an ormerod 2 and wanting something a bit more reliable and larger, i aim to build this great printer from davids blog [miscsolutions.wordpress.com].

I was wondering if anyone who has built this or knows could answer these questions.

1. in the printed parts it requires "carriage truck for 2020 extrusions" where do i find the designs for these, am i missing something obvious ? The only link i could find is this but i don't believe it is right
[www.youmagine.com]

2. Similar topic to the above: are the "endstop switch mounts" the same as found on the regular mini kossel?
3. I would like to use dual extrusion on this, if i re designed the effector plate, could it be made to work with the e3d chimera?
4. Finally i aim to convert my ormerod 2, hence using all its motors and electronics etc for the new printer, i assume this is ok?

Thanks for your time

Olly

1. That carriage will work if you plan on using the mini v wheels.
2. The endstop switch mounts from the MK will not work on 2020 extrusion. Try this https://github.com/Jaydmdigital/Kossel_2020/blob/master/endstop.stl which is basically the same thing just upsized to fit on 2020. Requires a M3 T-Nut and an M3 Screw then the endstop and the 2.5mm screws.
3. These two effectors should work, same spacing and size as mini kossel effectors. http://www.thingiverse.com/thing:923885 & http://www.thingiverse.com/thing:648836 Also I recommend sticking to carriages/effectors that have the arm points 40mm apart like on the MK, allows for easier replacement parts and such so you can use other peoples models designed for the mk.
4. All electronics should work just fine on the MK. Just remember to convert the firmware from a cartesian setup to a delta setup or bad things will happen.

1. You can find the files for the printed parts I used at [github.com], also the carriage truck design I used is at [www.thingiverse.com]. I adjusted the width of the standard Mini Kossel roller carriage truck to suit my rollers and the slot size in my 2020 extrusions. You may need to do the same as your extrusion slot size is probably different. Make sure the slots are not too wide for the rollers.

2. See 1. I adjusted the thickness of the endstop switch mounts to suit the carriage trucks, and the size to work with 2020 extrusion.

3. If you visit the E3D site, I think you will find that someone has already published a Kossel effector design to accommodate the Chimera.

4. I think the motors used on the Ormerod should work OK on the Kossel even though they have lower torque. But you are taking a bit of a risk dismantling your Ormerod before you have your Kossel working, because you may find that you need to print more parts for the Kossel after you have dismantled the Ormerod. The electronics isn't too hard to shift between them, but consider getting new motors. You may wish to consider using 0.9deg/step motors - I expect to publish a blog entry on the results of upgrading mine shortly. One possible source of stepper motors is [www.omc-stepperonline.com] if you can wait a few days for them to arrive.

btw if you are ordering the metal corners from Robotdigg, then I recommend you also get the metal carriages with built-in belt tension adjusters.

Edited 1 time(s). Last edit at 08/01/2015 04:11AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you very much for both of your replies!

I'm using the same extrusions as you David so the carriage you linked will work fine!
Also my ormerod is actually broken so i'm getting the parts printed via a local 3d printer hub quite cheaply so its not too much of a worry.
Thanks for your help all the metal arrives this week so ill be beginning construction soon.

thanks again

Oliver

I have just published a new blog entry describing some upgrades to my Kossel derivative, including 0.9 degree/step motors. It's at [miscsolutions.wordpress.com].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
I have just published a new blog entry describing some upgrades to my Kossel derivative, including 0.9 degree/step motors. It's at [miscsolutions.wordpress.com].

Interesting reading!

The 0.9 motors seems to increase the surface quality quite a bit looking at the pictures, would 1/32 steppers make the same difference?

I can tell you that the motors from steppersonline does not a D-cut shaft either, but they were really quick to deliver them!

Quote
Koenig
The 0.9 motors seems to increase the surface quality quite a bit looking at the pictures, would 1/32 steppers make the same difference?

1/32 drivers might make some difference on 1.8deg motors, but probably not as much. Microsteps are less accurate than full steps, and the incremental torque for a 1/32 step on a 1.8deg motor will be around half the incremental torque for a 1/16 step on a 0.9deg motor.

Quote
Koenig
I can tell you that the motors from steppersonline does not a D-cut shaft either, but they were really quick to deliver them!

Which model of motor did you buy? These [www.omc-stepperonline.com] show a D-cut shaft in the image. Did yours have flying leads, or a JST connector?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42

Quote
Koenig
The 0.9 motors seems to increase the surface quality quite a bit looking at the pictures, would 1/32 steppers make the same difference?

1/32 drivers might make some difference on 1.8deg motors, but probably not as much. Microsteps are less accurate than full steps, and the incremental torque for a 1/32 step on a 1.8deg motor will be around half the incremental torque for a 1/16 step on a 0.9deg motor.

Quote
Koenig
I can tell you that the motors from steppersonline does not a D-cut shaft either, but they were really quick to deliver them!

Which model of motor did you buy? These [www.omc-stepperonline.com] show a D-cut shaft in the image. Did yours have flying leads, or a JST connector?

Exactly the ones you link to in your blog.

Flying leads.

On the order-page there was info about D-cut and different connectors for the wires but nowhere to choose or supply instructions / requests....

But they sure were quick to deliver, less than 24hours after my order the shipment was registered in Swedish customs.

I just did some sums, and it appears that in order to get travel speeds higher than the 166mm/sec that I currently achieve using the 0.9 degree/step motors, the power supply voltage needs to be increased. So for anyone building this printer from scratch and choosing 0.9deg motors, I suggest you also choose a 24V power supply, 24V E3Dv6 hot end, and 24V 40mm x 10mm hot end cooling fan. I will be upgrading my machine to 24V in the near future.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].