Fine tune your MK3 Y axis  

Re: Fine tune your MK3 Y axis

Good idea John!
You might think like this?

Re: Fine tune your MK3 Y axis

Oh yeah , now that's getting sexy. I think that would work and fix the issues. I like it, I wish you were a fusion 360 man so I would not have to attempt to redraw these myself as well lol. Good work again, I think we are onto something good here. That what I had picture in the head just ran out of time last night after I printed the one I was thinking with I had that idea. Thumbs up.

Re: Fine tune your MK3 Y axis

John, if you want to try, you can import a STEP file and play with.

Re: Fine tune your MK3 Y axis

Any chance of getting a third screw into the stepper motor?

Re: Fine tune your MK3 Y axis

Any chance of getting a third screw into the stepper motor?

No, sorry, there's too little space for it.
But maybe a rear console gets more stable and better?

Re: Fine tune your MK3 Y axis

Oh yeah , now that's getting sexy. I think that would work and fix the issues. I like it, I wish you were a fusion 360 man so I would not have to attempt to redraw these myself as well lol. Good work again, I think we are onto something good here. That what I had picture in the head just ran out of time last night after I printed the one I was thinking with I had that idea. Thumbs up.

What problem are we solving here? The belt tension pulls the shaft, the mount might flex a hair, but presses motor body against metal frame. Is this the concern?

Re: Fine tune your MK3 Y axis

I have not read all the posts from you RHDreambox, but I really like your work and will for sure test and print that stuff.
The best would be to have something like a changelog / test history if possible 🙂 and all informations stored in one place - like a summary.

I want to ask you if you can have a look on the heatbed frame mount?
I think this U-Bolts can produce the big problems if they are not mounted perfectly.

Re: Fine tune your MK3 Y axis

Oh yeah , now that's getting sexy. I think that would work and fix the issues. I like it, I wish you were a fusion 360 man so I would not have to attempt to redraw these myself as well lol. Good work again, I think we are onto something good here. That what I had picture in the head just ran out of time last night after I printed the one I was thinking with I had that idea. Thumbs up.

What problem are we solving here? The belt tension pulls the shaft, the mount might flex a hair, but presses motor body against metal frame. Is this the concern?

This... I was wondering if the motor actually bumped the frame so I got out the feeler gauges and found a hmmmm... The motor (installed with the belt tightened) on the belt end has 0.23mm clearance and the rear of the motor has 0.03mm ???? i would guess the belt tension would create the opposite condition. So I brought up the official y motor mount .stl to check if there was an intentional (small pun) angle on the part to maybe correct for the bend. Nope.. the part is square. So ??? I would guess that if you were worried about the bracket bending under load you could shim the rear of the motor to the frame. Have to measure the motor to see if the rear frame is smaller than the front frame..

Re: Fine tune your MK3 Y axis

That's why I moved the holes for the motor 0.15 mm so that the motor housing would lie directly against the rear frame.
I wanted to prevent the engine from moving at load.
If you also install a motor holder on the rear of the motor, the risk is eliminated.

Re: Fine tune your MK3 Y axis

That's why I moved the holes for the motor 0.15 mm so that the motor housing would lie directly against the rear frame.
I wanted to prevent the engine from moving at load.
If you also install a motor holder on the rear of the motor, the risk is eliminated.

Right. The MK2 used a tear motor holder, had to because of the threaded rods (hated those things!). They simplified on MK3 since it’s not needed but had a small dimensional error you fixed. I don’t see need for further action, especially drilling a hole a critical frame member. I’m worried people have lost sight of the issue.

When do you get your printer?

Re: Fine tune your MK3 Y axis

John, if you want to try, you can import a STEP file and play with.

It seems like this STEP file isn't compatible with Fusion 360. I tried several times to import but there is a problem.
I also tried to download and open the zip with different extractors but nothing.
Could you upload agin this file?
Thanks in advance

Re: Fine tune your MK3 Y axis

i discover the Fusion 360 has some problem with their servers. So i think the problem is related to them.
I will try later again
Sorry

Re: Fine tune your MK3 Y axis

When do you get your printer?

My printer is at UPS in Jönköping Sweden 60 km from me.
They indicate that they can not deliver due to the weather! It came 30 mm snow today 😮
Delivery from Prague to Jönköping took 20 hours. The last 60 km takes at least 80 hours (weekend)!

Re: Fine tune your MK3 Y axis

John, if you want to try, you can import a STEP file and play with.

It seems like this STEP file isn't compatible with Fusion 360. I tried several times to import but there is a problem.
I also tried to download and open the zip with different extractors but nothing.
Could you upload agin this file?
Thanks in advance

The file imports nicely into Creo.. I'd be curious to try the original inventor file if you don't mind.

Re: Fine tune your MK3 Y axis

Oh yeah , now that's getting sexy. I think that would work and fix the issues. I like it, I wish you were a fusion 360 man so I would not have to attempt to redraw these myself as well lol. Good work again, I think we are onto something good here. That what I had picture in the head just ran out of time last night after I printed the one I was thinking with I had that idea. Thumbs up.

What problem are we solving here? The belt tension pulls the shaft, the mount might flex a hair, but presses motor body against metal frame. Is this the concern?

This... I was wondering if the motor actually bumped the frame so I got out the feeler gauges and found a hmmmm... The motor (installed with the belt tightened) on the belt end has 0.23mm clearance and the rear of the motor has 0.03mm ???? i would guess the belt tension would create the opposite condition. So I brought up the official y motor mount .stl to check if there was an intentional (small pun) angle on the part to maybe correct for the bend. Nope.. the part is square. So ??? I would guess that if you were worried about the bracket bending under load you could shim the rear of the motor to the frame. Have to measure the motor to see if the rear frame is smaller than the front frame..

I'm a DA. The number at the rear of the motor is 0.3 not 0.03... sorry. the motor is tilted in the opposite direction expected if the mount was flexing due to belt tension..

Re: Fine tune your MK3 Y axis

When do you get your printer?

My printer is at UPS in Jönköping Sweden 60 km from me.
They indicate that they can not deliver due to the weather! It came 30 mm snow today 😮
Delivery from Prague to Jönköping took 20 hours. The last 60 km takes at least 80 hours (weekend)!

Sorry man. I’ve been there. Very frustrating when the anticipation is that high.

Re: Fine tune your MK3 Y axis

Decided to play. I did a stiffened motor bracket and a riff on that with 3 bolts. I've printed (Taulman n-vent) the stiffened 2 bolt and have it on my Printer. I haven't printed the 3 bolt yet but maybe I will. There's no kill like overkill.. Clearance between belt mount and 3rd bolt is about 1.5mm Added 2 bolt stiffened installed pic

Re: Fine tune your MK3 Y axis

John, if you want to try, you can import a STEP file and play with.

Hi RHDreambox,

I noticed my Y axis motor mount was actually pretty warped. The stepper mount was warped, looked like maybe it came off the bed or something when Prusa printed it? Bad quality control. This caused the backside of my stepper to be about 1.5mm away from being against the frame, caused my pulley to be tucked inward and probably slightly applying uneven pressure on the belt, and maybe even making a pivot point out of the mount and vibrating? After seeing this beefed up mount, I decided to print it out. Fit is perfect so far, and the motor is very much against the frame now. I didn't drill a hole for the third screw, but I suspect the lip extending outward will help keep the motor from tucking inward at the pulley again if there was any cause to that besides a bad print on Prusa's part.

Printing a test cube now to see if this helps any with my vertical banding issue on the Y axis. I doubt it, but I will try anything at this point.

Re: Fine tune your MK3 Y axis

Printing a test cube now to see if this helps any with my vertical banding issue on the Y axis. I doubt it, but I will try anything at this point.

😀 Huge improvement, I am down to REAL ringing/ghosting now that I can tune out with accel/jerk settings, repeating line is gone!

Re: Fine tune your MK3 Y axis

Nice to hear that it worked better with a fine-tuned motor holder 😀
Is it PLA or PETG in your calibration cube?