Change in bed temperature without any reason

can someone post a pic?

 

Hi mike,
I posted some pictures in this post:
http://forums.robo3dprinter.com/index.php?threads/heated-bed-problem.2724/
I'm not sure which picture you want. I could post pictures if you let me know which ones you need.
For me I would need to know where to attach the fan , but still waiting on tech. support to reply.

 

go to thingiverse and search "Ramps fan mount"

That's where/how you mount it. Blow cool air on the ramps board, specifically the orange polyfuse

 

Thanks I wasn't sure where they would go.
I have extra fans I took off my computers, which I could use but im not sure if there's a compatibility issue.

 

as long as it blows air and runs on 12v you'll be fine.

 

I recall a youtube video by jerry on how to connect a fan . I'll probably make the fan mount as my next print , and hope the fans I have are 12v, im almost certain they are.

 

If it's a computer fan it 100% is. 5v fans are uncommon and 24v fans would work on 12v but you'd never pull one from a PC

 

Mine without a fan was fine with the bed heated to 65C but when I added a second print cooling fan the bed heater had to work too hard and tripped the Polyfuse after several layers. I added a fan to the ramps board using the universal ramps bracket in thingiverse and the problem is solved for me. The next stage is to upgrade the Polyfuse and MOSFET and I'll also install an SSR (solid state relay), which apparently makes the other 2 component upgrades unnecessary. There info about this in other threads, just search do some searches, that's all I've done. I'm no electronics expert so it's all about trust for me. The SSR upgrade came up in a private discussion with Ziggy, he and I will be implementing it when the parts arrive, I think he may do a guide after some testing.

My advice, put a fan on the ramps board and order a RGEF1400 Polyfuse and a IRL1404 MOSFET so you have them on hand if needed. Print the ramps fan brackets in PLA with the print cooling fan off or very low so you don't trip the Polyfuse.

 

**update**
Jerry at tech. support is sending me a fan with wiring , I just need to print the ramp fan Brackets.
I'll probably order the polyfuse as well just in case.
Thanks to everyone for all the help!

 

Got my Fan today. Took 2 days from when I spoke with tech support. That's real fast!
Also came with the wires to connect to the board. Heated bed is back in business

 

Forgot to mention If you need info on where and how to install the fan , here is the original post :
http://forums.robo3dprinter.com/ind...t-heat-bed-cutting-out.1299/page-3#post-12186
Installing the fan took roughly 1-2 minutes easy peazy