Help with custom firmware settings for Rostock Max V2 upgrade

Veti

see https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors

So the usual practice is to set the motor current to no more than about 85% of the rated current

The duet wifi only supports interpolation at x16. the motors will be a lot quieter with that. At the moment you have disable interpolation
Do a Test print and see how the first layer looks.
if you dont need ftp or telnet there is no reason to enable it.

Metallikahn

@veti said in Help with custom firmware settings for Rostock Max V2 upgrade:

see https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors

So the usual practice is to set the motor current to no more than about 85% of the rated current

The duet wifi only supports interpolation at x16. the motors will be a lot quieter with that. At the moment you have disable interpolation

Do a Test print and see how the first layer looks.

if you dont need ftp or telnet there is no reason to enable it.

I'd seen that document earlier, but it makes a lot more sense now. I've gone back and set it up for 16x (on) in the configurator. Figure 1.2A is a good starting point for my chosen motors. I downloaded the spreadsheet linked in the wiki page and ran the numbers for my steppers (which were pretty close to the defaults in the spreadsheet). I really don't care so much about the stepper noise since I have my printers in a fairly large shop area where it isn't a factor. I'm assuming 16x interpolation is better than just running it at 256x, or somewhere in between, for other reasons than just noise?

As far as stepper Max Speed goes, the spreadsheet shows me a worst case speed of around 125mm/sec (just about spot on with the V4's stock steppers) @ 12V. The V4 firmware shows a max speed of 250mm/sec. Is the general rule of thumb to just double it and plan to print slow near the edge of the plate?

I see I can gain over double the speed by going to 24v. What would you suggest for a Max speed in the firmware at 24v?

On the subject of 24v, I was planning on keeping it at just 12v to match my current PSU and hotend, but for a few $ I can easily get a 24v heater cartridge and it's not that spendy to just get a good AC Silicone heating pad for the heatbed. I've got a spare 240 watt 24v/10A psu that came stock with my Prusa Mk3. Assuming I run the heatbed off from the AC mains, would 240 watts be sufficient to run my steppers, extruder, 40 watt hotend, and duet3d/fans? I estimate at max Amps on all the motors and hotend I'd be drawing around 9A, leaving me 1A for the board/fans/etc. If I'm running the steppers at the 1.2A I currently have them set, it comes down to around 6.5 +board/fans/etc... Is that Enough acceptable headroom to be safe and sufficiently powered?

I'm already over budget on what I was going to do for an upgrade, but at this point, a little bit extra to go full 24v with an AC heatbed seems to be a much more practical choice (especially since I'll have the whole printer tore down for the switch over anyway). If I can use the PSU I have on hand, however, that would save me a few $ and make me feel a bit better about it.

Veti

@metallikahn said in Help with custom firmware settings for Rostock Max V2 upgrade:

I'm assuming 16x interpolation is better than just running it at 256x, or somewhere in between, for other reasons than just noise?

more steps will require more cpu resources. on a delta this could become more problematic at high speed.
If you want more accuracy, 0.9 degree steppers are the way to go.

As far as stepper Max Speed goes, the spreadsheet shows me a worst case speed of around 125mm/sec (just about spot on with the V4's stock steppers) @ 12V. The V4 firmware shows a max speed of 250mm/sec. Is the general rule of thumb to just double it and plan to print slow near the edge of the plate?

It depends also on the weight of the effector and the acceleration settings. Easiest thing is to try and if you get layer shifts reduce speed or acceleration.
At 125mm/sec you could be limited by your hotend. Higher speed will certainly require something like a volcano hotend.

On the subject of 24v, I was planning on keeping it at just 12v to match my current PSU and hotend, but for a few $ I can easily get a 24v heater cartridge and it's not that spendy to just get a good AC Silicone heating pad for the heatbed. I've got a spare 240 watt 24v/10A psu that came stock with my Prusa Mk3. Assuming I run the heatbed off from the AC mains, would 240 watts be sufficient to run my steppers, extruder, 40 watt hotend, and duet3d/fans?

Fans are also voltage specific. 240 watt without heated bed is plenty.
See
https://duet3d.dozuki.com/Wiki/Choosing_the_power_supply

Metallikahn

@veti said in Help with custom firmware settings for Rostock Max V2 upgrade:

more steps will require more cpu resources. on a delta this could become more problematic at high speed.
If you want more accuracy, 0.9 degree steppers are the way to go.

Ok, now that you say that, I seem to remember reading that a year or two ago. Basically 16x interpolation with .9 steppers gets you the improved motion you might expect from a higher microstepping with 1.8 degree steppers and also saves on the Processing power.

It depends also on the weight of the effector and the acceleration settings. Easiest thing is to try and if you get layer shifts reduce speed or acceleration.
At 125mm/sec you could be limited by your hotend. Higher speed will certainly require something like a volcano hotend.

Yep. The speed concern was mainly for a safe setting in the firmware. Very rare that I use an actual print speed in excess of 60 mm/s. The hotend and smart effector will be the only weight hanging in the middle to start. Depending on how the Titan performs in the new setup, I might persue a remote drive extruder like the Nimble in the future... (so still not much of a factor.

Fans are also voltage specific. 240 watt without heated bed is plenty.
See
https://duet3d.dozuki.com/Wiki/Choosing_the_power_supply

Excellent! I missed that article while browsing earlier. Not too worried about the fans since e3d has lots of 24v fan options and I'll be building a custom layer fan anyway. Looks like if I just grab an AC Silicone Heater pad, a 24v heater cartidge and a couple of 24v fans I should be good to go!

Thanks for the help! I feel like I got a much better handle on how this is going to come together now.

dc42

@metallikahn said in Help with custom firmware settings for Rostock Max V2 upgrade:

I see I can gain over double the speed by going to 24v. What would you suggest for a Max speed in the firmware at 24v?

My delta isn't a Rostock, but it has a 300mm diameter printable area, 360mm rods, 24V power, and 0.9deg 1.68A motors. It can do 250mm/sec travel speeds. It can't quite manage 300mm/sec at the edges of the bed using my standard acceleration settings.

@metallikahn said in Help with custom firmware settings for Rostock Max V2 upgrade:

Basically 16x interpolation with .9 steppers gets you the improved motion you might expect from a higher microstepping with 1.8 degree steppers and also saves on the Processing power.

It's better than that. 0.9deg motors give you nearly twice the torque per unit angular error than 1.8deg motors, so you get better resolution. Whereas increasing microstepping from x16 to x32 typically doesn't improve resolution, because of the drop in incremental torque per microstep.

Don'r forget that you also need a DC-AC SSR to control an AC bed heater.

Metallikahn

@dc42 said in Help with custom firmware settings for Rostock Max V2 upgrade:

My delta isn't a Rostock, but it has a 300mm diameter printable area, 360mm rods, 24V power, and 0.9deg 1.68A motors. It can do 250mm/sec travel speeds. It can't quite manage 300mm/sec at the edges of the bed using my standard acceleration settings.

I'm shooting for between 300-304 (Over 304mm and the ballcups Juuuust touch the belts!) printable with SeeMeCNC's 340.5mm Carbon fiber arms. Can just manage 300 with the 290mm arms I currently have, but it's really hit or miss and the steppers are definitely slipping by that point. Definitely looks like 24V is the way to go. That'll give me a near identical hardware setup as yours in that particular area. As I mentioned, I rarely use a print speed over 50-60mm/s (even with a .6-.8 nozzle), but if it can handle that kind of speed it should really do a great job on the lower speeds for me, which is exactly what I'm after!

It's better than that. 0.9deg motors give you neatly twice the torque per unit angular error than 1.8deg motors, so you get better resolution. Whereas increasing microstepping from x16 to x32 typically doesn't improve resolution, because of the drop in incremental torque per mitostep.

I've been looking at doing the .9 upgrade as long as I've been eyeballing the Duet wifi upgrade! Always assumed the two should go hand in hand. If increased microstepping ends up being a wash on results, then x16 interpolating is definitely the way to go!

Don'r forget that you also need a DC-AC SSR to control an AC bed heater.

Got exactly that coming. Was going to use it to boost my Stock bed to 24v, but the AC heater makes a lot more sense and frees me up a whole 24v supply to run everything else.

Grabbed an e3D 24v 40W Precision heater (should pair well with my pt-100!) a 24v fan for the hot end, and figured... as long as I'm swapping steppers, I might as well go all out and drop in a set of Astrodyn Dampners while I'm at it. This might not be the greatest Rostock Max V2 ever, but It's still gonna be one helluva machine!

Still researching for a good silicone heater that will sit/mount flat between my aluminum spreader and Onyx build plate. Keenovo shot me a quote for $76 delivered on a custom designed (with precut screw holes) 305mm 400 watt AC heater that came with a preinstalled PT-100 sensor and centrally located wires. ( I'd have to cut and enlarge the Onyx hot bed's center hole, but at that point I'm just planning on using it as an insulator for the wood frame anyway.) Only issue is it might take upwards of 4-8 weeks to arrive. For and extra $30, I might be able to get it in 3-4 weeks. As cool and well priced as the custom design is, a 280mm disc would pobably do the same job just as well. I've got them running me a quote on an off the shelf 280mm plate and throwing in a PT100 sensor for me to self install. If it's not too bad, I'll probably jump on it.

dc42

@metallikahn said in Help with custom firmware settings for Rostock Max V2 upgrade:

Got exactly that coming. Was going to use it to boost my Stock bed to 24v, but the AC heater makes a lot more sense and frees me up a whole 24v supply to run everything else.

You need different types of SSR depending on whether the bed heater is low voltage DC or mains voltage AC.

Phaedrux

@metallikahn said in Help with custom firmware settings for Rostock Max V2 upgrade:

throwing in a PT100 sensor for me

Don't forget that to use a PT100 you will need the daughter board.

Metallikahn

@dc42 said in Help with custom firmware settings for Rostock Max V2 upgrade:

You need different types of SSR depending on whether the bed heater is low voltage DC or mains voltage AC.

got one specc'ed exactly the same as SeeMeCNC sells for running their AC heaters.

Metallikahn

@phaedrux said in Help with custom firmware settings for Rostock Max V2 upgrade:

@metallikahn said in Help with custom firmware settings for Rostock Max V2 upgrade:

throwing in a PT100 sensor for me

Don't forget that to use a PT100 you will need the daughter board.

Yep! Included in my first post. Just some of the many $ I've spent with Filastruder in the last couple weeks!