Motors on top?

My big custom delta will have a heated chamber and a serious 500w 12x12 silicone heater attached to a 6'm tooling plate that radiates heat. The bottom end of this thing is cooking! On top there are a few layers of glass and air before the top panel which has the electronics and such. I was just getting ready to manually extend my stepper motor cables when it hit me I cam just put the motors up top where it's cool and save the effort of extending them. Any downside to top mounted motors on a delta?

I've turned my Kossel XL upside down too and clamped the frame down on a thick MDF plate. I'm pretty happy with it, also the endstop cables didn't have to be extended.

The bed is now fully insulated underneath, which is another benefit. I have an 5mm thick aluminum bed with 350mm diameter and it takes only 15min. to heat it up to 110°C.

Edited 1 time(s). Last edit at 12/28/2016 05:13AM by o_lampe.

I can't see that it makes any difference whether motors go at the top or bottom in terms of function. I can see the logic of top mounted motors in terms of less cabling, especially if the electronics are at the top also. It also depends on where you machine will sit. A kossel XL is a big unit so if its on the floor, motors and electronics in the top makes sense, much easier access for maintenance and upgrades. Mine is on a table so I am not getting up to the top easily, so all I have between my top horizontals is a spool holder.

Let us know how the enclosure is going, I'd like to enclose my XL also and I'm keen to see what schemes work best.

Olampe - 15 mins to heat your bed? What heater are you using?

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

I have a Zonestar D810 which has motors and electronics up top. Seems to work well. I guess wherever you put motors and electronics, you'll still need to run wires top to bottom.

Quote
o_lampe

The bed is now fully insulated underneath, which is another benefit. I have an 5mm thick aluminum bed with 350mm diameter and it takes only 15min. to heat it up to 110°C.

I'd rephrase that to say 'it takes an agonizingly long 15min. to heat up to 110°C'

My 8mm thick >400mm diameter bed (325 printable) takes about 5 minutes to go from <20°C to >120°C. I'm using a 110v 500w 300mm diameter heat pad.

Motors and electronics on top is an especially good option when using a mains powered bed heater. You put the PSU and the SSR under the bed, and all the rest of the electronics and wiring at the top. The only wires running from top to bottom are the bed thermistor wires, SSR control wires, and 24V power wires - and those don't need to be thick because they are not carrying the bed current. If you're not using Duet WiFi electronics, you might also want to extend the USB or network socket to the bottom of the printer, because having a cable plugged into the top is rather ugly.

---

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].

Oh you just reminded me! How do I extent these tiny thermistor wires?!

disregard, just stripped one, they're wayyy thicker than I thought, won't be a problem.

Quote
etfrench

Quote
o_lampe

The bed is now fully insulated underneath, which is another benefit. I have an 5mm thick aluminum bed with 350mm diameter and it takes only 15min. to heat it up to 110°C.

I'd rephrase that to say 'it takes an agonizingly long 15min. to heat up to 110°C'

My 8mm thick >400mm diameter bed (325 printable) takes about 5 minutes to go from <20°C to >120°C. I'm using a 110v 500w 300mm diameter heat pad.

I don't want to start a pi$$ing contest, but obviously, what goes in must come out. I'm happy with my 200W/24V silicon heater