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Hello all,

Ok, good news before the bad. I got my Rostock Max all calibrated, with the hot end and Onyx bed heated to operating temp first. I did all of the Repetier setup, even got the hot end primed (did the 300mm extruder priming). Woohoo can't wait to FINALLY print!!

Bad news is, I've discovered that with the Logisys power supply, I can't heat both the hot end and the Onyx bed at the same time for very long. After a few minutes, there's a mechanical click sound, and the Logisys power supply goes out. I know this because the power supply's cooling fan stops running (and of course, the LCD display attached to the RAMBo goes out.) Flipping the power supply off and and back on again brings it back. If I heat ONLY the hot end or ONLY the Onyx, I can stay powered up indefinitely, so I doubt I have a short in either one. Just in case, I have checked for shorts both at the hot end resistors with a mutitmeter and visually at the power supply connectors , and found no shorts.

I have the power supply wires to the RAMBo done correctly; I have the four yellow and four black in parallel for the needed current and the single blacks and yellows as per Gene's assembly manual.

My guess is the Logisys doesn't like the current draw from heating the hot and and the Onyx, and some internal circuit breaker trips.

Anyone else having/had this problem? It sure seems like an inadequate power supply issue. Gah! I just want the setup to be OVER!! X(

I really need to get this up and running for our office, any help is greatly appreciated!

Sounds like you may be correct. It could also be a short that occurs during heating due to expansion.

If you have a volt metere check the leads of the onyx immediately after the trip to see.

Hope you get it figured.

Do you have a metal plate on top of the Onyx heat bed? If so that could be the cause of the short as Flateric mentioned.
You must cover the exposed traces on the top of the Onyx with Kapton tape if you use a metal plate on it. See here to
see where the Kapton tape must go: http://forum.seemecnc.com/viewtopic.php?t=1257&p=6265
If your power supply is truly defective a lot of us use a 12 Volt 30 amp unit which I will give you a link to.
I want to note that it is possible to run the heat bed at 24 volts to increase the speed at which it reaches temperature.
Before using a 24 Volt power supply on the Onyx search the forum for others who have done that by typing in the following:
site:forum.seemecnc.com 24 volts Type this into google search box, google will find all instances of 24 volts.

The link to the 12 volt power supply that many of us use is here:
http://www.amazon.com/Universal-Regulat ... wer+supply

I just wanted to give you other options rather than a pc type power supply. The disadvantages to the other types is that they don't fit inside the cabinet like the pc model does.
Good luck with your build.

Carl

I think they just started shipping the Logisys power supplies, the older kits came with a different PSU so there may not be a lot of people with direct experience of it on here.
Could be a bad PSU, could be a short as mentioned.

I have a similar issue. Sometimes the MAX will annoyingly just shut down mid print (printing ABS), typically after half an hour. Flipping the switch fixes the issue, but the print is obviously ruined. I have to double check that it's a Logisys, but I got the kit three weeks ago.

Initially I thought it was the Rambo shutting down due to overheating, but the PSU fan stops, so it has to be the PSU. I'm at a loss as to what to do about it, other than crossing my fingers and hoping the prints complete.

- Karl

Do you have a model number for the Logisys supply?

foshon wrote:Do you have a model number for the Logisys supply?

Logisys PS480D-BK.

It is nominally 480 watts, but only rated for 16A of +12V.

Thanks all,

For now, how do I wire a separate Rambo controlled PSUs for the Onyx? I'm sure I could figure it out if there are separate power in pins for the hot end and the Onyx, I don't have the Rostock in front of me at the moment, can't remember

Or, what if I change the number of paralleled power wires? Would dropping from four to three or going up to five help?

Foshon, above the barcode on the Logisys box it reads PS480D-BK.

Shutting off in mid abs print? So much for that 14" build height with a Logisys!

I had a Logisys power supply that went bad in the first 5 or so hours of printing. At first it just shut off in the middle of a print. After doing that 3 or 4 times, it would let me move the motors but not heat the bed. Then it would light up and connect, but I couldn't move the motors...

I got a replacement from John and haven't had a bit of trouble since then.

designfactore wrote:Thanks all,

For now, how do I wire a separate Rambo controlled PSUs for the Onyx? I'm sure I could figure it out if there are separate power in pins for the hot end and the Onyx, I don't have the Rostock in front of me at the moment, can't remember

Or, what if I change the number of paralleled power wires? Would dropping from four to three or going up to five help?

Foshon, above the barcode on the Logisys box it reads PS480D-BK.

Shutting off in mid abs print? So much for that 14" build height with a Logisys!

The image shows that power applied to the 1st connections (orient the board properly) goes to the heated bed.
If you use 24V here do not exceed 15 amps or the fuse on the Rambo will blow. Another way to do it is to supply
all power inputs with 12 volts and connect the heat bed output to a DC-DC SSR input. The output of the SSR would
be connected to 24 Volts and feed the heated bed. Be sure to use an inline fuse when going this route. Cambo3d has
a good writeup in the build section that you should read to see how he connected 24v to the heat bed.

I'm not sure what brand my power supply is, but it was doing the same thing as yours. I could heat ether the hot end or the Onyx but not both. I had ordered a 24 v power supply to heat the onyx but I didn't get my dc-dc ssr until just yesterday. So I took another PSU out of an old computer and just wired it up to the power input on the Ramb for the Onyx. So one power supply powers the hot end, motors and logic, and the other powers the heat bed. It seems to be working great for me. Eventually when I get time I will replace the borrowed PSU for the 24v one and an ssr.

Thanks guys!

Jim, thanks for sharing, it's good to know that I'm heading in a direction where our Romax will hopefully be reliable. We will be using it daily in office!

For now I'm printing out our first attempts by gently preheating the glass bed with a heat gun, though our current PSU won't heat both the Onyx and the hot end at the same time, it is happy to power just the hot end. My first prints are coming out pretty tight despite!

Eagle, thanks for the suggestion, got it, we've done things like that in house with other electronic projects, didn't occur to me here! If I understand correctly, your suggestion is to:

--Detach the wires from the Rambo that go out to the Onyx (the heat bed outputs)
--connect a SSR to the Rambo where the wires we just removed were
--get another PSU for the Onyx, wire it to the Onyx and essentially use our SSR to connect or cut off the PSU current to the Onyx

designfactore wrote:Thanks guys!

Jim, thanks for sharing, it's good to know that I'm heading in a direction where our Romax will hopefully be reliable. We will be using it daily in office!

For now I'm printing out our first attempts by gently preheating the glass bed with a heat gun, though our current PSU won't heat both the Onyx and the hot end at the same time, it is happy to power just the hot end. My first prints are coming out pretty tight despite!

Eagle, thanks for the suggestion, got it, we've done things like that in house with other electronic projects, didn't occur to me here! If I understand correctly, your suggestion is to:

--Detach the wires from the Rambo that go out to the Onyx (the heat bed outputs)
--connect a SSR to the Rambo where the wires we just removed were
--get another PSU for the Onyx, wire it to the Onyx and essentially use our SSR to connect or cut off the PSU current to the Onyx

Yes, you understand perfectly. Some of us are using a 24V supply for the Onyx via the SSR but try this at your own risk. I have not read of any problems
but I don't want the responsibility if something burns up your Onyx. You can put the 24V directly into the Rambo Hotbed inputs also but read this thread first http://forum.seemecnc.com/viewtopic.php ... &start=110 and
the page following the link.

So John and Julie from SeeMeCNC sent me a replacement power supply, same brand but different model as requested. Been printing for hours with no issues! The bed heats up reasonably fast, about the same amount of time as the hot end takes. A tip here : use a heat gun to boost the warmup time of the Onyx! Just be sure to keep the gun moving and heat evenly to prevent warping. So far the new power supply is maintaining 230 C on the hotend and 80C on the bed just fine. Btw, PSU swapping is a super easy installation, there's enough clearance to get the old out and the new in without having to disassemble the base whatsoever.

Thanks for all the help and suggestions, I may yet do that 24volt bed mod, but first, dual extruders (hopefully, Ihaven't gotten a clear idea on how feasible that is). Anyone have video of that working?

designfactore:

If you do decide to use an SSR be sure to use a heat sink made for that purpose under the SSR. They get too hot
to run without a heat sink. There have been instances where users burned up the SSR because they did not use one.

I use an old washcloth on the bed. Acts like a blanket and traps the heat so it reaches operating temp faster.

g.

geneb wrote:I use an old washcloth on the bed. Acts like a blanket and traps the heat so it reaches operating temp faster.

g.

I use a wash cloth on my bed too, it helps to keep the bed bugs clean.

*facepalms*

I should have expected that. *sigh*



g.