Best / Largest Print to date...

CNCModeller

Hi All,
Thought the community might be interested in my largest print to date. The polar printer is really getting there now. Feel free to comment on the video via YT, it'll help get my channel back up and running too!

Anyway seasons greetings one and all!

All the best
Barry M

https://youtu.be/mLz1vDJkfgs

tenaja

Thanks for sharing--that's very cool!

I have a slide for the z axis of a similar size. My plan is to use it to lift a corexy stage. Perhaps I should consider polar.

Have you seen any benefits or disadvantages to the polar system? Obviously, the center bearing has to be pretty stout, complicating the bottom, but it would simplify the other axis. Any other comments on what drove your decision, and thoughts now that it's completed?

Are speed or quality effected? (What speeds can you achieve?) What's your resolution at the outer edge like?

Thanks!

o_lampe

@cncmodeller
Very impressive, especially for a moving bed.
In the video, I thought I saw some Z-wobble on the support part on the rear? At least there was a regular change in light-reflection...hard to say on a video.

These loong smooth rods on the Z-axis: do they bend? I've seen supported smooth rods, which might be an improvement.

CNCModeller

Hi @tenaja , its definitely moving from the long slog to get it working into enjoyable print results.

@tenaja said in Best / Largest Print to date...:

Have you seen any benefits or disadvantages to the polar system? Obviously, the center bearing has to be pretty stout, complicating the bottom, but it would simplify the other axis. Any other comments on what drove your decision, and thoughts now that it's completed?

So I think the main disadvantage is that not many people use it so the firmware whilst workable, my gut says there are still a few bugs to work out. But not being fluent with the code it's something I'm dependent on the duet team for. The last couple of beta revisions definitely helped.

Mechanically its simple, very compact for its print volume and cost effective. However... it requires to be set up very precisely to get good results and decent print tolerances especially at max Z. The machine needs to be very well "Trammed" I used a laser in the centre of the bed as the bed axis of rotation needs to track the path of the nozzle when set to X0,Y0. I built in a lot of adjustment from the get go and I've needed all of it.

The bed bearing is very robust, and took me several iterations to get it to the point that it was usable at max Z.

Are speed or quality effected? (What speeds can you achieve?) What's your resolution at the outer edge like?

Obviously the major issue is not being able to print at the bed centre, this isn't an issue for the parts I want to create. I can print at 200mm/s at the bed edge its basically limited by melt rate there. I run a GT2 20T motor pulley that drives a 720T bed pulley so resolution is only slightly less at the edge than a standard printer.

Hopefully that helps, have a great holiday season!

All the best
Barry M

CNCModeller

Hi @o_lampe ,

@o_lampe said in Best / Largest Print to date...:

@cncmodeller
Very impressive, especially for a moving bed.

Thanks, its definitely getting there!

In the video, I thought I saw some Z-wobble on the support part on the rear? At least there was a regular change in light-reflection...hard to say on a video.

That's warpage due to the large thin wall un-supported surface area.

These long smooth rods on the Z-axis: do they bend? I've seen supported smooth rods, which might be an improvement.

Yeah I considered those but the were very expensive in the UK. I plan to support the Z rails in the centre as I have open linear bearings as per your link.

The radius axis will vibrate from side to side if it catches a zit on the print, but it rarely happens and is relatively well damped.

Anyway, happy holidays!

All the best
Barry M

mrehorstdmd

@cncmodeller Well done! Very impressive!
~~What size nozzle are you printing with and how long did that print take?~~
Nevermind...just saw the video link...

o_lampe

@cncmodeller said in Best / Largest Print to date...:

the firmware whilst workable, my gut says there are still a few bugs to work out. ...
Mechanically its simple, very compact for its print volume and cost effective.

Not too many other polar printer around, maybe because Delta was first?
Kudos for your pioneer work, but if I had to print tall objects, I'd go for a Delta. Because they're easier to align and they don't know about singularities in bed center.

A few years back, I suggested a rotating bed for a Delta, but only for infinite (overnight) printing. The bed would be stationary while printing. The center of rotation was the Z-tower.
One could even place three Deltas around the disc shaped bed and do mass production. Sorry, still daydreaming. I guess I had too much christmas-fudge

CNCModeller

@o_lampe said in Best / Largest Print to date...:

Kudos for your pioneer work, but if I had to print tall objects, I'd go for a Delta. Because they're easier to align and they don't know about singularities in bed center.

Thanks for the kudos, my issue with Delta is how tall they are for the print height. I wanted something that'll fit in a domestic setting i.e. 600mm wide doorways and lower ceilings, and since I'm mostly printing hollow things the singularity isn't much of an issue for me.

It's the print volume to printer volume ratio that sold me on polar. Plus what engineer doesn't relish the opportunity to figure something cool out from almost scratch lol.

Enjoy your fudge lol.

All the best
Barry M

o_lampe

@cncmodeller said in Best / Largest Print to date...:

what engineer doesn't relish the opportunity to figure something cool out from almost scratch lol.

I'm with you, although I went too far ahead with my hashPrinter. Now I have to wait for RRF and slicer dev-teams to make it work.

CNCModeller

@o_lampe said in Best / Largest Print to date...:

@cncmodeller said in Best / Largest Print to date...:

what engineer doesn't relish the opportunity to figure something cool out from almost scratch lol.

I'm with you, although I went too far ahead with my hashPrinter. Now I have to wait for RRF and slicer dev-teams to make it work.

Anything significant in engineering requires a multidisciplinary team, and that one seems pretty strong to me... good luck with your build too...