Hi Folks,
This is my polar printer, it's down for a bed bearing upgrade at the moment, but she's definitely running and the duet's working a treat.

Working volume is 570mm diameter by 1150mm tall.

Here's some footage of her in action...

https://youtu.be/nvOLMP2IJIU

The YouTube playlist for the build so far is here:

https://www.youtube.com/playlist?list=PLWjZVEdMv1BY82izahK45qKh-hp3NFkix

My channel is www.YouTube.com/CNCModellerUK

I'm hoping to come to TCT so will drop by the stall. If you want some better pictures just let me know!

Cheers
Barry M

@dc42 MQTT integration would be awesome... my home automation uses an mqtt broker and openhab so I could check print status securely anywhere via the openhab internet gateway and mobile app.

See you on Thursday all being well...

@dc42 Update - Sorry its been a while have has car trouble...!

So the issue with the weird steps per degree was down to belt tension, that's resolved now.

This is my config file it's pretty simple.config.g

Unfortunately the Gcode file is 43meg so I cant upload it.

I've just generated code for the first 20mm of the part in S3D and here's just the base, the full test print is 1100mm tall. Its a spiral thin wall print.

TallTestConeStructured_0-20mm.gcode

The printer struggles on the brim radially from where the wall stiffeners are, and also on the main part wall when running above 125%. The printer will run faster but stutters quite a lot. The previous video link is still representative.

As an aside it also looks like the max deg/sec limit on the bed doesn't work when doing relative rotational moves, i.e. +120deg. Is this normal? I think the limit is working for normal operation.

Any thoughts would be much appreciated.

Many thanks
Barry M

@dc42 The radius carriage is static as it's just printing a 300mm dia thin wall cylinder which printed fine on the old setup.

See the first few seconds of this video to see what I'm printing. It's the same code file running on the old setup.

Old printer setup

The only subtle change to the config file is that I'm actually using a step per degree of 961.33333 instead of 960 which is 3x320 that was used previously on the ungeared setup. Not sure if using a non integer increases the processing workload.

The 961.3333 is because I haven't got the tension quite right on the drive belt and I think it's having an effect similar to that of a harmonic drive effectively changing the 720t gear size by one tooth. It's an effect I've seen before but haven't managed to tune out yet on this drive config.

Will post gcode and config tonight if that is still useful.

Many thanks
Barry M

@dc42 MQTT integration would be awesome... my home automation uses an mqtt broker and openhab so I could check print status securely anywhere via the openhab internet gateway and mobile app.

@dc42 it says duetwifi v1.02 on the board but it's an Ethernet board. I'm having issues doing a test print at 300mm dia see video link below. I Want to be able to print down to a dia of 50mm, albeit r min is set to 0 at the moment to support calibration after a bed axis bearing and stepper drivetrain upgrade. Bed max print diameter is 600mm.

behaviour video link

Any thoughts would be much appreciated.
Cheers
Barry M

Hi All,
I've recently put a 3 to 1 reduction on my polar bed motor for better acceleration and am now getting co-ordinated hunting in the stepper speed of both the bed and extruder. Was wondering if there is a max stepper frequency that I may be saturating. Im running 40deg / sec at 960 steps per degree (16 microstepps). It seems to run fine for the bed alone but starts to hunt when actually printing...

Any thoughts?

Cheers
Barry M

See you on Thursday all being well...

@dc42 said in Novel/Unusual/Large printer videos wanted:

I didn't know we had anyone using a polar printer seriously!

If all goes well with this prototype I'm hoping to end up with a farm of these and so far it's been straightforward all things considered.

Let me know (after TCT) if you find any issues with it.

Only thing so far is it doesn't seem to be limiting rotational speed near the centre of the bed but that might be me setting it up wrong. Will be in touch once I've got a little more experience.

PS - it looks like you can do some very tall prints!

Hopefully so, the first cheap bed bearing failed at about 1500 revolutions so the tallest height I've achieved in testing is only 300mm tall. My laser jig tool suggests that she should be good to print to about 1150mm but only a successful test print will confirm it.

I'll be in touch after TCT.

All the best
Barry M

Hi Folks,
This is my polar printer, it's down for a bed bearing upgrade at the moment, but she's definitely running and the duet's working a treat.

Working volume is 570mm diameter by 1150mm tall.

Here's some footage of her in action...

https://youtu.be/nvOLMP2IJIU

The YouTube playlist for the build so far is here:

https://www.youtube.com/playlist?list=PLWjZVEdMv1BY82izahK45qKh-hp3NFkix

My channel is www.YouTube.com/CNCModellerUK

I'm hoping to come to TCT so will drop by the stall. If you want some better pictures just let me know!

Cheers
Barry M

This would be very cool, and It'd be relatively easy to create a longer thin "heated" nozzle perhaps out of a wire wound hypodermic needle. The heating would just maintain temperature from the heat block to the tip...

Either that or a 5 axis setup with a nozzle that could be sent alt azimuth demands... I could envisage 5 axis mill surfacing toolpaths could be wrapped around the exterior of a part!

Definitely one for the future...

Very cool, definitely interested in following your work!