A Bigger Slice Of Pi ...

Do I need ~6meters of GT2 belt? (I have 5 meters but I can always order more)

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mikes3ds
Do I need ~6meters of GT2 belt? (I have 5 meters but I can always order more)

You will need approx. 2.1 meters per tower in an un-interrupted length (This allows for belt clamping on the Carriages).

I would suggest you look for the Carriages that Pointy did in the main Cherry PI3 thread as he has built in a tension adjuster they are on Page 16 about half way down the page Pointy's modified tower carriages

I have these on mine and they work very well tho I did use some commercial M3 Thumb nuts rather than the printed variants he designed (This due to the fact that my other printer is using a large nozzle for speed which makes small parts come out slightly off and using ABS as well).

HTH

Doug

Alright thanks. I will print Pointy part.
Did you buy Low Profile Screws M5 30mm, and any spacers (if so what size)

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mikes3ds
Alright thanks. I will print Pointy part.
Did you buy Low Profile Screws M5 30mm, and any spacers (if so what size)

No I didn't need to the ones that came with the wheels were long enough.

Doug

Put it all into sketch up, to get a idea of the size also going to try and make a enclosure for it maybe.

About how long is your bowden PTFE tube for the cherry pi XL?

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mikes3ds
About how long is your bowden PTFE tube for the cherry pi XL?

Sorry Mike missed this My Bowden tube is approx 850-860 mm long (Well that's the amount of Filament that I need to unload anyway)

ZPL's Web interface for the Duet makes this task very easy just configure the unload/load distance hit the button and it flies it out slowing down for the first part of retract and final part of the load.

HTH

Doug

Thank you dougal


Just double checking the rod size.
6x 6mm Rod 280mm (Without ball bearing?)

I machining all my rods, so I am going to make sure they are the same length.

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mikes3ds
Thank you dougal


Just double checking the rod size.
6x 6mm Rod 280mm (Without ball bearing?)

I machining all my rods, so I am going to make sure they are the same length.

Mike

What total height are you going for as I have just had to increase my Rods to 472 (including Balls) But I have got 450 mm extrusions for the sides and 1000 mm for the tower's and a 400 mm dia bed.

Doug

1000mm Height (Extrusions)
350mm Bottom/Top (Extrusions) *Note they are currently 500mm I still need to cut them to 350
310mm Glass & Heated Plate.
280mm Rods

What do you think?

Edited 1 time(s). Last edit at 04/22/2015 05:07PM by mikes3ds.

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mikes3ds
1000mm Height (Extrusions)
350mm Bottom/Top (Extrusions) *Note they are currently 500mm I still need to cut them to 350
310mm Glass & Heated Plate.
280mm Rods

What do you think?

The rods sound rather short to me, however it all depends on the delta radius. The delta radius is the difference between the outer bearing radius and the inner bearing radius. The outer bearing radius is the radius of the circle that the mid points of each pair of upper rod end bearings are on, when the carriages are at the same height; so a bit less than the radius that the towers are on, depending on how far in the bearings are from the towers. The inner radius is the radius that the mid points of each pair of lower rod end bearings are on; so approximately the effector radius. The delta radius is marked "arm radius" in this image, which assumes that the effector is centred:



Once you know the delta radius, the length of the rods should be about twice that. For my Midi Kossel with a 300mm diameter printable bed area and 355mm horizontal extrusions (so not much different from yours), the delta radius works out as 171mm and the rods are 350mm between bearing centres.

---

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].

I have never had an issue, on the Cherry Pi variants, using 80% of the distance between tower centres for the delta tubes (they then have 8mm ball bearings attached which adds another 8mm to total rod length). On the standard Cherry Pi that equates to a tube length of 225mm and on the larger, 4XL to 280mm. Although it may not be strictly correct in terms of delta mathematics it seems to give a good balance between actual print radius (200mm on the standard machine and 300mm on the 4XL) and print height (250mm standard, 550mm 4XL). I've personally built about 20 standard machines and 3 4XL variants using these lengths and they all print fine. I suspect, if there are issues, the problems lie elsewhere than the delta rod lengths.

Edited 1 time(s). Last edit at 04/23/2015 06:24AM by AndyCart.

Hi

After recovering with 3d printing due to the Rasperry Pi 2 release i am planning to build a big delta. The 4XL looks pretty nice to me but i want to have
a large print height as i am planning to experiment with printing some foils. So a 250mm print bed should do but i would like to have a maximum printing height. So what would be the recommended extrusion length's? I was thinking about 120cm 2040 extrusions but i don't want to overdo it and ruin print quality. I was also thinking about larger extrusions but i think they have also larger openings and then the delrin roller won't fit anymore?

Thanks
Tim

Ok so a lot of things.Thanks for community for the help answering questions!

The community was correct about the rods 280mm, I have 284mm Rods do not get the whole length needed. I have a 310 mm diameter plate, I think it can get to around 200mm.

Besides that everything else was a great design!!! Thanks Andy, and every one who helped.

HERE ARE PICTURES of my first and second print.


Here is a video of auto calibration.
[www.youtube.com]

Here is it printing
[www.youtube.com]

I am still working on cleaning up wiring and trying to get heatbed up to ABS temperatures, also I am going to lengthen the rods. Also getting the best settings, and maybe even more precise calibration!

Hi all,

I have been reading through this thread and the Cherry Pi III one, and created a calculator to help scale these machines.

It's not perfect, but I thought I would post it here and see what you guys thought, as well as any recommendations for how to improve it.

The biggest challenge that I have seen is finding arm length; I used a method that takes a bit from a bunch of other posts I have come across.

Given a desired build diameter, arm length is the minimum length required to reach the farthest edge from a given tower with the arm at a 20* angle to the horizontal at that point.
Whether or not the arms can dip below this is unknown to me, however I felt that this was a good estimation without pushing the limits.

Let me know what you guys think, as well as if you have anything I should add.
I included some other things as well like delta radius, the "80% Rule", length between towers, maximum build plate possible on frame (just reaching the base extrusions as well as reaching over them), etc.

[docs.google.com]

Thank you
Kyler