PeterE builds a 3d Printer

Gallery, Projects and General > Project Logs

<< < (23/36) > >>

awemawson:
Does the psu run warm? If so the Arduino should be below not above.

(This is the industrial computer support part of me speaking from 30 years fixing things where the designer didn't think!)

PeterE:
Hi Andrew,

Thank you for the info, very useful!

To be true I actually don't know yet ... haven't got the thing completely up and running.

Have tried to avoid heat from the PSU affect the electronics by having the air stream from the PSU fan to draw from the rear of the PSU and out through the side of the frame (can be seen above). That should avoid a direct air flow heat at least,

Then I have heard that the stepper drivers may become quite hot and thus require additional cooling by their own fan. This is something I will have to find out as the whole contraption starts working ;-)

/Peter

picclock:
Hi peterE

Looks like your going great guns. I've just finished glueing the cork sheet to the back of the bed heater. Good to hear your son is helping - father son thing can be good. I measured temp rise of 104C with small heatsink on z driver. Made larger heatsink. Will update blog with piccys when I get a chance. Good to see your progress.

Best Regards

picclock

PeterE:
Thanks picclock!

Oh, what kind of glue do you use to stick the cork to the heaater? and what kind of glue/tape do you use to stick the heatsinks on the stepper drivers?

BR

/Peter

picclock:
Hi PeterE

I had some 'duff' lowish performance silicon heatsink plaster lying around which I used to glue the cork. Halnziye Hy910 is the code. Seems to be OK. rated for extended temperatures. Its soft enough for removal even when fully cured. Would have used JB Weld for permanent fixing at elevated temperature but you would have to destroy the parts to remove it. For temperature tests on drivers I used Akasa thermal adhesive tape. After measuring and test I replaced the tape with AG TermoPasty for a permanent fix. Measurement was made with a thermocouple on the underside of the driver chip pcb, so pretty accurate. For tape I am using Kapton tape for its high temp properties.

However, there are some areas of concern. The thermistor measures the temp of the pcb, not the temp of the glass surface. Whilst it is easy to set the pcb temp, the temp at the top of the glass will show great variation. Drafts from movement will help conduct the heat away, the thermal resistance between glass and pcb is likely a variable high number. So not exactly precision. However, it may be adequate for this application. Short of packing the space in between with thermal grease and hoping little improvement seems possible. Will do further measurements when setup and may modify it to take a therocouple sensor attached (probably clipped) to the printing surface of the glass.

Re Z axis movement. How have you solved the angular movement/change of height issue with those couplers. I have two but am not sure about using them. My current thinking is plastic/rubber sleeving, alowing the threaded rod and motor spindle to touch, with the rod end rounded, so point contact. The sleeve will allow small angular errors with consistent radial position. Clamps at motor and rod ends will ensure no slippage. Have you any thoughts on this matter :scratch:

Best Regards

picclock

Navigation

 Message Index

Go to full version