Upsizing Kossel 2020 - 1200mm extrusions?

Hello everyone! First time poster, (very very very) long time lurker!

I got a partially built (incorrectly) FolgerTech Kossel 2020 that I picked up dirt cheap. I want to upsize it significantly while I am rebuilding it.

What I am concerned about is stability of a height of 1200mm extrusions. Note that I will be using linear rails attached to the 2020 extrusions.

I've calculated two variants with parts I have on hand already:

250r x ~300h w/500mm linear rails
[danalspub.com]

400r x ~615h w/1000mm linear rails
[danalspub.com]

The 250r has the best angle of the 288mm on-center rods I have for high speed edges (30°). The only issue with 250r is I have a cosplay helmet I'd like to print, and it needs 270mm to clear.

I also have a set of 1000mm linear rails that I'd like to put to use - without building a second Delta printer. But obviously something that large with 2020 extrusions may need a level of bracing I am not comfortable with.

And no, I can't attach it to a wall for where it will be sitting.

Thanks!

Edited 1 time(s). Last edit at 10/08/2021 07:37PM by eduncan911.

I agree, 2020 isn't stiff enough for that size printer. I use 2040 for my 1m high delta. [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].

I used 2550 from Misumi on my meter high delta. I wouldn't recommend anything less. The top and bottom are torsion boxes. It is also all aluminum.

Thanks David! Your Delta gave me a lot of ideas in the past, and partially why I was upsizing! Though, I could have sworn you were the one with the 2020 extrusions. May have been someone else.

Quote
etfrench
I used 2550 from Misumi on my meter high delta. I wouldn't recommend anything less. The top and bottom are torsion boxes. It is also all aluminum.

Thanks! yeah, hoping on keeping my existing 2020 ends... which limits my ambitions, yep.

I used 2020 extrusions for the uprights originally, but upgraded to 2040.

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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].

the 2020 isnt stiff enough. i regret it a lot but it is a little late . Next built would be sized up to at least 2040

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Delta Printer
Duet 0.8.5 firmware 1.19

Thank you to everyone! In the end, I settled on 800mm uprights with 2020s (stock was 600). All in all, it will give me about 250r x ~300h center, with a max angle of 24 degrees.

[danalspub.com] (remember to select Kossel 2020 settings)

I went a little higher on the verticals to leave room for a PrintShift setup.

Edited 1 time(s). Last edit at 11/09/2021 02:53PM by eduncan911.