High Temperature Bearings

Hi,

I've just joined the community after doing research for a little while and am designing an SLS printer at the moment. I'm going to be using a heated chamber and am designing the powder spreader. I'm thinking of using smooth rods and linear bushings, but am struggling to find them for reasonable prices that can withstand 180 Celsius.
I've found a good price on high temperature ball bearings (https://www.bearings-online.co.uk/item/2386/BRL/6200-ENC-ZZ-270C.html), but they would require using the bearing set design that the Mendel uses. The problem with that design though is that I can't use printed parts inside the chamber as they'll melt.
I assume I could have the a bearing housing milled from aluminium if necessary but then then increases the cost substantially.

My current idea involves pulling the roller gantry along steel rods using steel wire fed outside of the heated chamber to the motor(s).

Anyone know of other options?

Keep in mind I will be (if all goes well) heating the powder chamber to 180 Celsius.

Thanks,
Waka

Edited 2 time(s). Last edit at 11/07/2016 12:16PM by Waka.

... have you checked for ceramic bearings? - there are hybrid with steel rings, or full ceramic types ... but didn't see linear bushings yet.

But better try to exclude or shield the sensitive parts by construction or by active cooling with ambient or chilled air ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks for the reply. I have looked at ceramic bearings yes, but they also don't seem to come reasonably priced as linear bushings. The bearing I listed would be suitable if I can mount them but I'm hoping to find a standard part to avoid milling. I've managed to remove all other heat sensitive parts outside of the heated chamber but this is the last one in the design that has to be inside.

I'm just looking into using a lead screw (or possibly 2) instead of the rods. As I won't require any bearings at all. I'd be hoping to have quite large pitch lead though. Does anyone know the pitch of some lead screws used in other printers for reference?

Thanks,
Waka

Hi all,

I've found some plain sleeve bearings I can use instead of ball bearings as they're a lot cheaper for the high temperature inside the heated chamber.

has anyone had any experience with this kind of thing?

http://www.igus.co.uk/iPro/iPro_02_0028_0000_GBen.htm?c=GB&l=en

Thanks

... this type of bearings have some "play" and can bind in dusty environments - so maybe not so good for powder-bed SLS ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I had read about that with bronze bushings especially. Igus offer more dirt resistant ones that i'll try first. If they don't work then I'll have to switch to a ceramic linear bearing like this: http://www.automotioncomponents.co.uk/en/catalog/linear/linear-ball-bushings/ceramic-linear-bearings/l1764.

But as the sleeves are less than a quarter of the price i'll try those first.