Hi all. Duet 3 board is great, this is a design comment.
I have been messing with a 5ft x 5ft x 7ft build volume printer for 3 years.
It had a 8mm heated aluminum bed (too thin) that operated well but warped badly. I have since disconnected it.
I have had surprising success with using regular contact cement as an adhesive over duct tape on the aluminum bed, at room temperature.
This is just an observation for those hobbyists who can't spend thousands on a large heated bed.
I hope someone finds this useful.

I built a very large printer with a heated bed that warped ridiculously with heat. I eventually broke it trying to level it so I started printing on the cold surface.
Long story short, I discussed the issue with my wife, a quilter. She suggested a basting spray she uses for sticking fabric together.
It worked amazing!!!
Stayed sticky through multiple prints.

@phaedrux I ended up ordering a duet3 mainboard. The only issue I foresee is I need one extra low power stepper driver. Is there not a way to connect my old duex5?

@phaedrux question 1: during inital paneldue startup. Bed works fine but I get the error message.
2: Firmware 3.0. I am trying to learn one version before upgrading. I am finding it too confusing for my 64 year old brain
3: I believe so. I am unsure because literally I forget what I have done after walking out the shop door. Refer to answer to question 2.
4: I will post my config .g and the results of sending M122 and M98 P"config.g" shortly.
Here they are:
40af8efe-3dbd-4afb-9110-11ce04ceffcd-M122M98.txt

I am 2 years into building a very large printer with no experience in mechanical engineering or coding. It has been a challenge, but mostly fun

I have had intermittent wifi issues since install. It would constantly disconnect. After reading a seggestion in forums I realized I had created a "faraday cage" between my duet board and modem. A cheap wall plug wifi booster, closer and without metal obstructions between modem and booster, fixed the problem.

@Phaedrux Thank you for your assistance. I really appreciate it!
I did not include an expansion board M122 because I don't believe I have one.
Thank you again. Hopefully I won't be bothering you any time soon.

@deckingman working perfectly. Thank you.

I just replaced the micro SD that came with my board with a A2 rated 32gig and Wow what a difference. So so much faster!!!
Given that my printer is huge 1.5m x1.5m x 2.0m and the Gcode is huge it has to make a big difference.

@dc42 stand alone. My file uploads went from taking several minutes to being instantaneous. Huge difference in speed. It remains to be seen how this will influence prints but I am enthused by this change.

@o_lampe Good thought but no the first layer appears clean.

Any ideas as to why I am getting these gaps in my concentric infill?

@dc42 stand alone. My file uploads went from taking several minutes to being instantaneous. Huge difference in speed. It remains to be seen how this will influence prints but I am enthused by this change.

I just replaced the micro SD that came with my board with a A2 rated 32gig and Wow what a difference. So so much faster!!!
Given that my printer is huge 1.5m x1.5m x 2.0m and the Gcode is huge it has to make a big difference.

@deckingman working perfectly. Thank you.

@deckingman said in 2nd extruder stepper to pull filament off 5 kg reel:

@damaged_goods said in 2nd extruder stepper to pull filament off 5 kg reel:

I am guessing that I can fine tune matching speeds by altering the ratio?

You could but it's a bit course. Obviously both extruders need to feed the same amount otherwise they'll be fighting against each other. You need to keep the hot end extruder the same and make any changes to the one that pulls off the reel (let's call it the "feeder"). So it's important that the steps per mm for each extruder is correct but if you need to make fine adjustments, then tweaking the steps per mm of the "feeder" extruder would give finer adjustment than changing the mixing ratio which will only go in 1% increments. You want to avoid the situation where the hot end extruder is pulling against the "feeder" extruder so it is preferable that the one pulling off the reel over extrudes slightly. So you'd want to reduce the steps per mm for that one slightly. i.e if 400 steps gave you one mm, and you "told" the firmware that it was 398 steps per mm, then 400 steps would give you (1/398*400 = 1.005mm. Obviously for a very long print, you might end up with quite a long loop of filament between the feeder and the hot end, in which case increase the steps per mm of the feeder slightly.
Edit. What you don't want is the filament between the two extruders being taught.

That is why I am adding the second feeder extruder.
Thanks again for your help

@deckingman said in 2nd extruder stepper to pull filament off 5 kg reel:

Now that I'm in front of my PC, I can give you a more comprehensive answer in case you haven't already figured it out. So define your tool (s) to use both extruders - e.g. M563 P0 S"Tool 0" D0:1 H1. Note that the extruder drives are referred to in the order that they were created in M584. So in your case, the extruder connected to the main board, drive 4 (0.4) becomes D0 in the M563 command, and the second extruder (0.3) is referred to as D1.
Then after M563, you need M567 to set the mixing ratio. As this is a "push-pull" arrangement we need to set both extruders to use 100%. So the command you need is M567 P0 E1.00:1.00 (where P0 refers to tool 0).

Thank you sir. I was just about to get into it. Your knowledge is greatly appreciated. It always makes me nervous when I start making somewhat blind changes to the config. It's been working so well!
I am guessing that I can fine tune matching speeds by altering the ratio?

@deckingman

'tools" that is what I was missing

I want to add 2nd extruder stepper, on a separate driver, to pull filament off 5 kg reel. Should be simple right?
M584 X0.0 Y0.5 Z0.1:0.2 E0.4:0.3
Driver 3 is the added stepper. which ever motor I list first works the other does not turn.
I initially tried running both motors (slightly different) off the same driver but the speeds differed. I thought using a spare driver would work as well.
Any ideas?

@chrishamm thank you