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Andy
 Andy
(@andy-12)
Eminent Member
MK2.5s Upgrade

Just finished! Was very interesting to say the least. Completed XYZ calibration OK. Set nozzle height"Z" in first print, good quality, a little noisier than original 2s, but overall pleased with the outcome.
Have one small issue with the X axis home. When the machine does its bed leveling the print head goes to the left and makes a terrible noise, then proceeds to complete the calibration, test or print like nothing is wrong. I checked the cabling at the back of the print head and it is not close to the frame. Does anyone have a guess?????

Original Prusa I3 MK2s with 2.5 upgrade; Original Prusa I3 MK3s; Slic3rPE; FreeCAD

Posted : 04/04/2018 4:07 am
jhoff80
(@jhoff80)
Trusted Member
Re: MK2.5s Upgrade

I know you said you for checked the cables hitting the frame, but it still sounds like your cables coming out the back of the X-carriage are preventing the endstop on the X-axis from triggering. It's a very small tolerance for what will work versus what won't (if the cables are off center by even a few mm it can cause problems in my experience).

Posted : 04/04/2018 4:46 am
Creative Cloisters
(@creative-cloisters)
Eminent Member
Re: MK2.5s Upgrade

If it sounds like grinding it may be that your x belt is a little too loose to provide enough force to trigger the endstop and is slipping?

Posted : 04/04/2018 9:49 pm
Guardian_DE
(@guardian_de)
Eminent Member
Re: MK2.5s Upgrade

The problem is that Prusa has a mistake in the X axis parts: Since the MK2.5 does not have TMC steppers it still needs the endstop to trigger. The arm that's supposed to trigger the endstop is about 3mm too short. You have to glue something onto the arm to have the endstop trigger.

I don't understand though why Prusa does not fix the design...

Posted : 27/05/2018 10:02 pm
ManelTo
(@manelto)
Estimable Member
Re: MK2.5s Upgrade

I think I will have the same problem. I haven't do the calibration yet but I can see than the motor's cable and the fan's cable are too big for the x-cover back and the carrier don't touch the endstop. If I put a little piece of plastic in the x-cover back then it could touch the endstop. But, is that correct?

Sorry for my poor English. I try to do my best.

Posted : 28/05/2018 10:27 am
GertL
(@gertl)
Reputable Member
Re: MK2.5s Upgrade

I do not have this isse. Its a close shave but it have been working since the upgrade (about 2 month now).

---
Gert

Posted : 28/05/2018 12:30 pm
Guardian_DE
(@guardian_de)
Eminent Member
Re: MK2.5s Upgrade


If I put a little piece of plastic in the x-cover back then it could touch the endstop. But, is that correct?

This is at least what I did and it works. But it still is an itch that I have to scratch, but this means remixing the back cover and disassembling the X axis including the cabling to the Rambo board. And this is something that I'm not very fond of 🙁

That some have the problem whereas others do not let's me think that Prusa used different sensors over time.

Posted : 28/05/2018 6:57 pm
ManelTo
(@manelto)
Estimable Member
Re: MK2.5s Upgrade



If I put a little piece of plastic in the x-cover back then it could touch the endstop. But, is that correct?

This is at least what I did and it works. But it still is an itch that I have to scratch, but this means remixing the back cover and disassembling the X axis including the cabling to the Rambo board. And this is something that I'm not very fond of 🙁

That some have the problem whereas others do not let's me think that Prusa used different sensors over time.

I think that the fan's cable is a little thick. The two cables (this one and the motor's cable) are complicated to put it in the groove. I worry that I can break some if I force them.

Yesterday I made the calibration and i done the test of the first layer and it like ok.

The only that i can't like it too much is the adjusting z done -0.900. With the mk2s gave me 0.350.

Sorry for my poor English. I try to do my best.

Posted : 29/05/2018 8:56 am
digibluh
(@digibluh)
Reputable Member
Re: MK2.5s Upgrade




If I put a little piece of plastic in the x-cover back then it could touch the endstop. But, is that correct?

This is at least what I did and it works. But it still is an itch that I have to scratch, but this means remixing the back cover and disassembling the X axis including the cabling to the Rambo board. And this is something that I'm not very fond of 🙁

That some have the problem whereas others do not let's me think that Prusa used different sensors over time.

I think that the fan's cable is a little thick. The two cables (this one and the motor's cable) are complicated to put it in the groove. I worry that I can break some if I force them.

Yesterday I made the calibration and i done the test of the first layer and it like ok.

The only that i can't like it too much is the adjusting z done -0.900. With the mk2s gave me 0.350.

That's your PINDA sensor.... you need to adjust it slightly higher to get lower than -900.... nothing to do with the upgrade. (well sort of since you did put the sensor IN yourself)

Posted : 10/06/2018 6:22 pm
digibluh
(@digibluh)
Reputable Member
Re: MK2.5s Upgrade


The problem is that Prusa has a mistake in the X axis parts: Since the MK2.5 does not have TMC steppers it still needs the endstop to trigger. The arm that's supposed to trigger the endstop is about 3mm too short. You have to glue something onto the arm to have the endstop trigger.

I don't understand though why Prusa does not fix the design...

because there's nothing wrong with it, mk3 part and 2.5 part are different and separate parts. mine hits the switch without issue and the tolerance is the same as the MK2S extruder, cables always touch the electronics case.

3mm too short? you printed the wrong part. it should say 2.5 on the back... or something's messed up with something else.... 3mm is way way off that it's user error here....

Posted : 10/06/2018 6:26 pm
ManelTo
(@manelto)
Estimable Member
Re: MK2.5s Upgrade

finally I got the Z adjust to -0.650. Well, the printer is doing a good job. I like the impresion, so I'don't touch more 😀 .

Sorry for my poor English. I try to do my best.

Posted : 11/06/2018 10:22 am
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