Rostock Max v2.1

[Pyropainter]

I would like to thank all on this forum that have helped me with my many questions, your knowledge has proved to be invaluable. Maybe this information will be of some use to you. As you may know I purchased a used Rostock Max v2. It had about 200 hours on it. I was able to get to know the machine before having a few troubles ie. failed resistor in the hot tend, power supply failure, and not related to the printer, the macro keys set up in Matter Control quit working properly. Thanks to the wonderful folks at Matter Control I was able to get thru that problem. Before reading the following, please keep in mind that I am not disrespecting the person from whom I purchased the machine or anyone at See Me CNC. I do know our host manufactures a fine product and it does not take too much reading to discover that many would agree. My most recent problem is being able to achieve a heated bed that is flat. Upon further inspection I have determined that none of the important parts are indeed flat ie. heat bed platform, heater, or borosilicate glass plate. Please checkout the following images of solutions to address my problems.

First is a 24 volt power supply fitted with a heating duct that will allow it to be vented thru the back of the machine.
[img]http://i.imgur.com/FweGVxG.jpg[/img]
Next is an image of my new heated bed platform. Made from cast aluminum tooling plate and then lapped. The counter bored holes are clearance for the blind T-nuts that have been mounted to the back side of the heat plate. I have taken care to not remove any of the black finish on the back side of the plate that would compromise the dc dc currant flowing thru the plate. I did however remove the finish to allow for adhesion of the T-nuts
[img]http://i.imgur.com/zqfeZ4J.jpg[/img]
Here is the image of the heated bed with the T-nuts installed. I plan to insulate the heated bed from the platform with cork.
[img]http://i.imgur.com/Upsfxaw.jpg[/img]
I also plan to use 1/4 inch thick lapped cast aluminum plate instead of glass. This has been quite a project over Memorial day weekend. I do hope that I can see some positive results when time permits.
Again thanks for all of the great information found on this site. I hope you all enjoyed your three day weekend, I know I did.

[Tincho85]

Hello, nice upgrades!!
Are you going to use that 24v PSU to run everything or just the bed? Of how many amps it is?
Remember to check your wiring, you will need thicker ones for a 24v.

I like the idea of the Tnuts, hope it works!

But, why 1/4 thick? That's like 6mm.
Won't a thicker aluminum bend/expand more? I'm using 1/8.

[Pyropainter]

The 24 vdc psu will supply power to the A and C input connections of RAMBO. I failed to mention that I will add a dc to dc converter to step down the power to 12 vdc. It will be connected to the B input connection (Logic Heaters and Fans). This was done because the fan on the hot end and the filament cooling fans are 12 vdc. I chose a 1/4 build plate because I have seen others doing so and it is what I had available to me. It is made out of mic 6 aluminum which is cast and milled. I am not worried about expansion so much as I am about warping and remaining flat. But you got me thinking and googled aluminum thermal expansion and found a helpful online calculator. If my calculations are correct the thickness will change by roughly .011mm and the diameter will change by .54mm. The change in diameter between the our plates should remain the same while your thickness change will be about half of mine. I will have to wait and see. Now it makes me think about taping PEI to the plate. Looks like more research for me.
Thank your for your insight