Heated bed cannot reach temp

[geolupulus]

Thanks Gene, I'll give it a shot!

[geneb]

let us know if that solves the issue. I'm curious to see what the time is it takes to hit 80C.

g.

[apostoly]

so when you say add more wire, just twist two red and blacks going to the rambo together and then solder the other ends onto the power plates?

When soldering onto the power plates, i'm assuming the wires don't have to be merged together as long as they are both touching the base?

[geneb]

As long as the solder joint is good, they don't need to be spindled together before you solder them down. It DOES make it easier.

g.

[nandalek]

Hey everyone! can't seem to reach 90C if I cover with towel it takes forever to reach 90C but as soon as I take it of it just drops to 75C I tried to add extra amps , by attaching two more yellow( 12v) from the source to the Rambo where the other four are and this is the best Ive accomplished this far ( before I couldn't pass 80C even covered with a towel)
I can't believe a brand new machine would`nt have the juice to heat its own heating element!

any suggestions are very welcome

[geneb]

You're adding wire to the wrong end. IF additional wiring works to help heat up problematic Rev3 beds, it's the wire from the RAMBo to the Onyx that needs to be doubled.

g.

[gajtguy]

Two areas need attention (extra wires)
1) The source heat input on the Rambo from the power supply
2) The wires going from the Rambo to the Bed need to be double or tripled as well

And verify which bed model # and Rev you have
And verify the voltage you read with a meter when the power is on to the bed.

[seanriddle]

Same problem here- brand new Max V2 with Onyx V3, can't get to 90 degrees on the bed. Extruder hits 225 fast. My kit only came with 5 feet of 18/4, so I had used some spare 16 gauge to go from the Rambo to the Onyx. I've since doubled that up (so 2x 16 gauge) but still no go. Without a towel it doesn't make it much past 75; with a towel it gets to 84 or so. I guess I'll order a better P/S to see if that fixes the issue.

[gajtguy]

I think the "official" suggestion, besides this awesome forum, would be to contact the seemecnc support email and see what suggestions they have.

email: [email protected]

[ZionPhil]

Two areas need attention (extra wires)
1) The source heat input on the Rambo from the power supply
2) The wires going from the Rambo to the Bed need to be double or tripled as well

And verify which bed model # and Rev you have
And verify the voltage you read with a meter when the power is on to the bed.

Just need Number 2, not number 1. You just need to add more wires from the rambo bed heat going to the bed. Double up the "red and the black".

I twisted mine and soldered together. Maybe a tight fit into the rambo connection point, but it can be done. What I am suggesting comes straight from SeeMeCNC via John Oly. I used to only be able to get up to 85c, not I can go 125c (3 wires on black and 3 wires on red)

[geneb]

ZionPhil, I really hope you didn't solder the ends of the wires that go into the RAMBo. If so, please undo that. You'll melt the connector on the RAMBo eventually. (The surfaces of the terminal block "squish" the wire, increasing the surface contact - when you put a soldered wire in there, it can't achieve the contact area required, resistance goes WAY up and there's a lot of heat generated as a result.)

g.

[ZionPhil]

ZionPhil, I really hope you didn't solder the ends of the wires that go into the RAMBo. If so, please undo that. You'll melt the connector on the RAMBo eventually. (The surfaces of the terminal block "squish" the wire, increasing the surface contact - when you put a soldered wire in there, it can't achieve the contact area required, resistance goes WAY up and there's a lot of heat generated as a result.)

g.

Gene. Noted. Have had it that way for 1 year now. No problems though.

[forrie]

Well I'm hitting 90C on my new build and Onyx Rev 3 easily. The wires running from the RAMBo to the Onyx are stock, I didn't double them up. My PSU is 750W and it's wires running to the RAMBo are much larger than the originals. I also made sure to use the 12v wires off two seperate PCI (video card) adapters to spread the load across a couple of rails on the PSU.

[Eaglezsoar]

Well I'm hitting 90C on my new build and Onyx Rev 3 easily. The wires running from the RAMBo to the Onyx are stock, I didn't double them up. My PSU is 750W and it's wires running to the RAMBo are much larger than the originals. I also made sure to use the 12v wires off two seperate PCI (video card) adapters to spread the load across a couple of rails on the PSU.

Did you try the stock power supply before using the 750 Watt one?

[forrie]

No I didn't...suppose I could run some wires into the bed and try.

[gajtguy]

Forrie - How long does it take to get to 90degrees with the power supply you installed? Just curious on the time factor.

[forrie]

About 10 minutes or so...

[geolupulus]

Welp, I added 2 wires each to + and - on the Rev3 (so 6 total) and still got no love from the heated bed, same temps as before. So SEEME sent me a new bed. Hopefully this new heated bed works. I hope I don't have to buy a new PSU.

[Greg von Plettenberg]

I Have just printed my first peek fan parts. I had the same problem. After waiting for more than an hour I covered the glass with tea towels, turned off the hot end heater and set the bed temp target to 115 c. I got it up to 87 degrees C max, so I just configured the slic3r to print with a bed temp of 85. This did the trick, but the one corner of the part lifted a bit ( probably due to glue contamination or less than ideal bed temp). I guess that its either a power supply problem, or maybe a PID issue, since the printer does not seem to have any trouble keeping the bed at 85 while printing, but if you leave it off for more than a few seconds, it drops right back down to 73 and refuses to budge without the above remedial actions.

I have a spare 300 w power supply, is there any easy way I can wire it into the printer and dedicate it to the heated bed ?

This issue is such a pity and i hope there is a solution because I am very impressed by the print quality, even without the fans or correct temps.

[Eaglezsoar]

I Have just printed my first peek fan parts. I had the same problem. After waiting for more than an hour I covered the glass with tea towels, turned off the hot end heater and set the bed temp target to 115 c. I got it up to 87 degrees C max, so I just configured the slic3r to print with a bed temp of 85. This did the trick, but the one corner of the part lifted a bit ( probably due to glue contamination or less than ideal bed temp). I guess that its either a power supply problem, or maybe a PID issue, since the printer does not seem to have any trouble keeping the bed at 85 while printing, but if you leave it off for more than a few seconds, it drops right back down to 73 and refuses to budge without the above remedial actions.

I have a spare 300 w power supply, is there any easy way I can wire it into the printer and dedicate it to the heated bed ?

This issue is such a pity and i hope there is a solution because I am very impressed by the print quality, even without the fans or correct temps.

The first two pins of your power input area are for the heated bed (outlined in red) you can connect the other power supply's 12V (yellow) where it says + and black where it says -

[geolupulus]

I ended up buying a new 750W PSU yesterday because I am impatient, and if it's not necessary I suppose eventually I can use it for an acetone vapor booth to finish my ABS prints. Anyway, I wired up the 750W PSU and it did not solve the problem. It does seem that I got a bum heated bed. Later, I installed the Rev 2 Onyx (with only one + and one - wire) and it heated up super fast and got right up to 90 degrees in a jiffy! Instead of 72 degrees in 30 minutes it got right to 90 degrees in 4.5 minutes! I am so excited to make bigger ABS prints!

[Eaglezsoar]

I ended up buying a new 750W PSU yesterday because I am impatient, and if it's not necessary I suppose eventually I can use it for an acetone vapor booth to finish my ABS prints. Anyway, I wired up the 750W PSU and it did not solve the problem. It does seem that I got a bum heated bed. Later, I installed the Rev 2 Onyx (with only one + and one - wire) and it heated up super fast and got right up to 90 degrees in a jiffy! Instead of 72 degrees in 30 minutes it got right to 90 degrees in 4.5 minutes! I am so excited to make bigger ABS prints!

I'm glad that you got it working. If I remember correctly it was the Onyx version 3 that caused you all the problems. How did you get the version 2?

[geolupulus]

I'm glad that you got it working. If I remember correctly it was the Onyx version 3 that caused you all the problems. How did you get the version 2?

That's the replacement that SeeMe sent me. Works for me!

[notarat]

I just ordered a Thermaltake 700w unit just to be on the safe side when mine arrives.

[CaptInane]

Out of curiosity has anyone ran a meter across their heat bed? I'm having the same heating issue with the Rev 3, so I thought I could compare my results.

Heat bed running, voltage across terminals: 11.2V
Current into heat bed: ~9A (which seems a bit high running on 18ga)
Resistance: 1.2 Ohm

By Ohm's law ours it's running at 100W. So, the stock

I've tried using an additional PSU (600W) to run just the bed. Pretty much had the same results. If anyone has theirs working properly, I'd much appreciate your feedback. Thanks!