Heated bed changes by rev level?

0110-m-p · Post by **0110-m-p** » Wed Nov 05, 2014 11:10 am

Just curious about heated bed changes and what kind of improvements were seen going from one to another.

My bed has "R2" on it and it looks like "Rev7" is the one that is currently available on the SeeMeCNC webstore.

I have been monitoring my bed temp the past 2 days and find that it has trouble maintaining temperature. Set at 95C it varies from 92.2-95.1C no matter how the PID is tuned. It only stays off for a few seconds and the temperature drops significantly and is then at 100% power again for a few minutes before it gets back to 95C.

I'm looking into doing a 24V PSU and SS relay to power the bed directly, but wonder if that is even worth while with my Rev2 bed.

Jimustanguitar · Post by **Jimustanguitar** » Wed Nov 05, 2014 12:02 pm

Here's my understanding of it.

Rev 1 in the beginning... It was round instead of square.
Rev 2 What most of us have. Unsure of the improvements over 1
Rev 3 Heating traces have a varied spiral for more even heating. Added a hole for LED heat indicator. *Never shipped due to high resistance, better suited for a custom 24v build, on sale now!*
Rev 4 Never existed. It was an incremental save between 3 and 5 that was never ordered.
Rev 5 The 'production ready' release of rev 3.
6&7... I can't tell you. I know that at some point the thermistor hole moved away from the perfect center. There was also an experiment to add an indicator LED for the hot-end too, but that's now been removed. Maybe 6 had dual lights and 7 removed it?

Other than bell/whistle features, I don't believe that there was a design tweak besides thermistor placement that affected performance between revs3 and 7. John and Steve would have to tell you the official word on the revisions, but's those are my guesses.

There isn't a direct correlation between bed rev and V1/V2 Rostock. It's been running changes the whole time, and V1/V2 is mainly a wood difference.

What is the geneology of the hot-end? I know it's evolved over time too. Anybody got the history on those?

Nylocke · Post by **Nylocke** » Wed Nov 05, 2014 12:32 pm

More insight on the Bed. I have a Rev 7 on my build, and my robotics team has a Rev 6. I haven't timed the heat ups, but I'm pretty sure that my Rev 7 on 12V heats up faster than the clubs Rev 6 on 12V. I take mine to 100C in no time (maybe 10 minutes) while it seems to take 20-30 minutes for the Rev 6 to get up to 90C. It could be that my PSU is better, some random one I had in my room, but I know mine heats up faster.

Earthbound · Post by **Earthbound** » Wed Nov 05, 2014 12:42 pm

I have a rev6. Tested a few days ago and found it will climb from 23-24c ambient to 100c in under 11 minutes. Using the stock power supply. I did up size the wiring to the Onyx bed.

0110-m-p · Post by **0110-m-p** » Wed Nov 05, 2014 1:21 pm

Thanks for the insight.

I wired my heated bed with a pair of 16ga wires going to each terminal and can get it to 100C if I wait forever.

90C is about 20 minutes
95C is about 30 minutes
100C is roughly forever but it will get there

Sounds like trying a Rev7 heated bed before upgrading to 24V PSU and SS relay would be the best/most cost effective thing to do.

guanu · Post by **guanu** » Wed Nov 05, 2014 1:35 pm

more insight: rev 5 - hot end led, theremistor relocation, resistance too high meaning wont get to temps without going 24v...
rev 6 - varied resistance we think due to copper trace thickness of the heater, and resistance was a little too low on some we tested.... heats up really fast (for most of them), but pushes the amperage close to fuse limit, hot end led removed as it was causing to much wiring confusion
rev 7 - re worked the copper tracing on the top, got a better consistency with acceptable ohm ranges, and gets up to temp in a reasonable time.. (tested to 100c, tho I never use it, I run my abs at 80-85c max) wiring remained the same as rev 6 and rev 3.... currently we are happy with the rev7

Guanu

Brian · Post by **Brian** » Wed Nov 05, 2014 3:06 pm

Jimustanguitar wrote: Rev 3 Heating traces have a varied spiral for more even heating. Added a hole for LED heat indicator. *Never shipped due to high resistance, better suited for a custom 24v build, on sale now!*

I have a Rev 3. It sounds like a rare collectors item. How much is it worth?

Jimustanguitar · Post by **Jimustanguitar** » Wed Nov 05, 2014 3:16 pm

Brian wrote:
Jimustanguitar wrote: Rev 3 Heating traces have a varied spiral for more even heating. Added a hole for LED heat indicator. *Never shipped due to high resistance, better suited for a custom 24v build, on sale now!*
I have a Rev 3. It sounds like a rare collectors item. How much is it worth?

Well... if it was new it would be $39 dollars. http://seemecnc.com/collections/parts-a ... heated-bed
But given the condition, the patina, and how you've had it refinished....

I'm actually working on a Rev3 "SuperBed" for 24v. I think it's pretty cool that they're available for a deal. Watch for my build log soon.

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Heated bed changes by rev level?

Heated bed changes by rev level?

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