Correctly assembled?

kai

Correctly assembled?
January 27, 2013 10:19AM

Registered: 12 years ago
Posts: 3

My friends and I recently bought a Prusa Mendel from 3dprintershop.se. However, I am not able to communicate with it. I have started going through to see what might be wrong. The Getting Started document says to check the end stops. I have found the ones for transversal and vertical movement and then started looking for the longitudinal. The cables for the two others were attached to the motherboard next to each other, so I followed the third cable. It ended up at a clamp at the front of the machine, and indeed I found a little push button there. But, AFAICT, there is no way for the sled to ever press that button. Has this been incorrectly assembled at the shop, is the clamp supposed to be attached somewhere else?
I attach a picture showing what it looks like.

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Wired1

Re: Correctly assembled?
January 27, 2013 08:06PM

Registered: 12 years ago
Posts: 525

This is the y-axis limit switch and would be triggered by the printer bed moving forward and as long as it gets tripped before the carriage drives into the frame it will all work out fine.
Probably triggered by the egde of the glass so adjust the height until the glass hits it.
You should still be able to communicate with the electronic controller even if the limit switches are wrong so you might be on the wrong track. If the limit switches are wrong you will still be able to motor the bed around with pronterface etc.
If the thermistors are disconnected it can send the electronics into a spin but you will still get something scrolling down the page on pronterface.
Have you got power to the electronics board? ie a LED glowing would be a start. Do you know that it has been loaded with firmware?

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Richmond, New Zealand
Thingiverse ~ YouTube

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waitaki

Re: Correctly assembled?
January 27, 2013 11:27PM

Registered: 12 years ago
Posts: 1,592

That's a strange looking assembly. For a start, the "Y" axis smooth rods should be under the threaded rods (the rod clamps hang down not up.) The switch that you refer to, as you've noted, is in the wrong place - it should be the on the inside of the smooth rod where it can be actuated by the print bottom plate. And just to get you started in "reprap speak", the left to right axis is "X", the front to back axis is "Y" and the up and down is "Z".
Anyway, are you saying that you bought this printer ready built?

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kai

Re: Correctly assembled?
January 28, 2013 05:03PM

Registered: 12 years ago
Posts: 3

Yes, as we are not very skilled with hardware, we bought a “ready to use” Mendel. If it is in fact incorrectly assembled we shall have to have stern words with the shop.

I suspect there in addition is a problem with the power supply, as I’m not seeing any light when I turn on the power. I shall go through the wiring and see if something got loose in transport.

Thanks for the explanation of the coordinate system, I’ve been uncertain if the convention was y-up or z-up. (See, complete noob :-)

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waitaki

Re: Correctly assembled?
January 30, 2013 03:33AM

Registered: 12 years ago
Posts: 1,592

Perhaps you could post a few more pictures of "around" the printer for us to peruse?

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lazzymonk

Re: Correctly assembled?
February 01, 2013 06:45PM

Registered: 12 years ago
Posts: 349

the prusa i2 with a single plate bed has the rods on top

[blog.reprap.org]

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kai

Re: Correctly assembled?
February 03, 2013 10:55AM

Registered: 12 years ago
Posts: 3

I attach a few pictures snapped around and from below the printer. Let me know if you want some specific view.

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lazzymonk

Re: Correctly assembled?
February 03, 2013 11:42AM

Registered: 12 years ago
Posts: 349

You might want to get some heat sinks for the stepper drivers

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Wired1

Re: Correctly assembled?
February 04, 2013 01:28AM

Registered: 12 years ago
Posts: 525

Looks pretty normal apart from the y-axis. The extra height of the roller on the motor and idler has forced them to put the y-axis rails above the end rods instead of under. This will reduce your overall build height but must have been necessary to clear the rollers. The y-axis limit switch (the one out the front) should trigger just before the y-carriage (or printer bed if you like) crashes into the end threaded rods and at the time it is triggered the printer head should be directly over the line around the perimeter of your red heated bed. So if this is not the case you will need to move the limit switch until it does this. It would normally (I think) trigger from the undercarriage of the y-carriage like off the bearing holder but your setup might be different.
The positioning of the y-axis limit switch is not critical as long as the printer bed doesn't hit the end and you get your full 200x200 print area.

_________________________________________________________________________________________

Richmond, New Zealand
Thingiverse ~ YouTube

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