8th Grade MP3DP

No Microcenter, I will just have to order some tape. Movement isn’t the concern, it was to protect the connections from bring “shorted” out…

All of mine are naked.

Man, that’s a lot of amps to short out!

But it is low voltage, so you couldn’t short them with your fingers, for example. “Please don’t lick the heatbed” would be a useful sign to make.

If you connected them with something metal, while it was trying to heat up, then yeah, that’s a problem, possibly a fire.

Aha! So that’s what those four holes are for. I was wondering if it was going to become obvious when I got farther along. What should I be doing with the six holes around the outside? And how do I mount the springs?

HELP! We finally got everything together and fired up the printer for the first time. DISASTER!!! With power supplied to the printer, after about 60 seconds, we smelled a burning smell. We removed the cover of the RAMPS and discovered that the heat bed MOSFEIT was super hot. The heat bed was getting hot as well. We were surprised because we had not called for the heat bed to heat up yet. All we did was turn the power on to the supply. Any suggestions on what to work on first. I have a SECOND RAMPS but don’t want to just throw that in in case we have screwed up some where else.
Jon and Rebecca

Lets see a picture of the ramps all wired up. Are any of the 3 mosfets touching?

all three were touching each other. Bent on top of one another… Pics to follow.

Here are the pics

they should not touch
separate them and power it back up see if they are still okay.

When it happened had you set anything to heat up?

Nope, it’s now smoking:-(

Gets hot within 5 seconds…


So the mosfet is bad.

What was the cause? They were touching initially and that shorted it?

I guess…

I have unplug the heat bed from D8 there’s no more smoking

I am getting 12.02 v at d8. Computer is not connected. Just turned on the supply

Yeah they fail “on” usually. usually it is from someone trying to connect a wire and hitting it with the screwdriver at the same time.

If you can solder I have spares in the shop. I can send one out.

ick. I was hoping you’d be lucky with the mosfets. Mine always die when they short, however briefly…

I replaced the ramps with my SPARE. Quadruple checked to make sure they were not touching. I think I know what happened. I think with I put the RAMPS in the ramps enclosure, I PUSHED them over top of each other. Stupid mistake on my part. I wouldn’t let Rebecca do it because I was afraid she would screw it up and here I go and do it. Now I have a GREEN light that flashes twice when first powering up. I think that is a good thing. NO RED LIGHTS telling us DANGER!!!