Solidoodle Workbench Overhaul (Page 1 of 4)

I have a lot of opinions on all of the above.  Maybe  next time you're on chat we should discuss it further.  Everything you mentioned I have extensive experience with.  Not to mention most of the upgrades you mentioned, I also have good used laying around.  I guess we should have had this conversation a few weeks ago.

For others reading: the WB in question came from me.  I am happy it found a home where it will get the proper upgrades and care.  With all of my time going into developing 2 new Printit models I simply didn't have the time to work on improving the WB.

Honestly not sure how many there were in the first place. The work bench was released at the same time as the press and the WB jr . Then there was cash flow issues and things fell apart.

I purchased a ft5 kit which has recently been upgraded. Not suggesting you start from scratch but you my want to look at the folger forum for inspiration.
And they just updated the kit to a 24 volt system,  something you may want to consider for a large format heater. 
The ft 5 uses a mks gen 1.4 board that may be an option it will handle two extruders.
As far as extruders I installed aero on my machine. Certainly an option for you, they have mirrored models for duel extruders.
As far as carriage bearings linear rails could be an option .
All depends on what machine you really want and your budget.

Tin

I still haven't started on the rebuild...too cold in the garage.

My WB is still sitting in my garage, right next to my laser engraver and a workbench full of Alfa Romeo parts. I'm trying to get a car project finished, and now I have military duty for a couple of weeks.

Realistically, I won't be able to start on it until June.

-Kevin

Thanks for the update. The newest  offering by e3d is the swapable tool head concept model they came out with then the aqua  just released and the areo  released a year ago.

And here is a board that you may want to look at

https://printedsolid.com/products/archim-1-0

This is a USA made board with some nice features but not a duet board.
The duet 2 seems very nice and a little cheaper.

There are 12"x12" PCB heaters out there...but a 12V version will pull over 24Amps at startup, so a relay or SSR and separate PSU is required for that...

SSR's steal a lot of resistance and will slow your heat times; a straight mechanical relay won't add resistance but will require PWM turned off and Bang-Bang activated. It will still click a lot and ultimately burn out the contacts.

A 24V should do well without any relay if you can find one; but then the Hotends need to be 24V as well.

Certainly possible...the higher voltage/lower amperage of a 24v heat bed will improve the heat loss situation with the SSR; not the fact that it is a separate power supply. You will still need a big heat sink and active fan cooling for the SSR if you use either 12 or 24v.

Otherwise, all you need to change is the heat cartridges on the hot ends to go full 24v for the whole machine. The stepper motors can already handle 12 or 24v. Then you only need one power supply for the whole system.

I took the old circuit board out of the Workbench...it looks like a regular Printrboard with a daughter board attached for the extra extruder and hot end.

Now I have another spare Printrboard!  My SD4 will live forever!

I'm kicking around ideas of how I'm going to mount the Duet WiFi and Panel Due.

Reading up on specs of current draw and handling capacity, I'm pretty much decided to go with 24v hot ends and bed heater.  If I understand correctly, the steppers are indifferent whether they're on 12v or 24v?

That is correct...

I've done the initial setup on the Duet WiFi.  You're compelled to use the online configurator (https://configurator.reprapfirmware.org if you want to take a look) to generate the initial configuration files.  The web interface is easily navigable once you get used to it, and is reasonably replicated on the Panel Due display.  I even have Repieter-Host talking to the Duet WiFi through the USB port!  This is great for me, because it gives me the option of continuing my present workflow process with R-H, or migrating to a purely browser-based method.

The configurator is easy to navigate and covers a multitude of parameters, but not everything is explained well.  Some sidebar text, hyperlinks, or better use of tooltips would be very helpful.  The Wiki discusses gcode commands and such, but is more suited for direct editing of the .g configuration files (which you can do through the web interface). For me, this resulted in several visits to the configurator as I homed in on the correct settings.  Once I got the configuration close to right, I simply resorted to editing the .g files.  More on that in a minute.

Some examples are:
Motors - do I need them to run forward or backward?  Endstops - at low end or high end?  Are we talking physically, or numerically in a Cartesian sense?  Fans - thermostatic control of fans to monitored heaters...the error checking didn't like what I was proposing, but I think I finally muddled through.  I won't know for certain until I order the hot ends, etc.

After uploading the generated files, I connected one axis at a time, and began testing; making configuration changes as I went.  For example, the X and Y axes run forward, while the Z axis runs backward.  I had to refine my bed dimension settings, and assert that I want home to be the right rear of the printer, not the left rear. 

The configurator gives you endstop options of active high/low (normally closed/open) z-probe, or motor stall current.  After I had tinkered with X and Y to satisfaction, I connected Z.  The Z axis went rogue on me, and bulldozed its way through the Z limit switch before I was able to issue the STOP command. After a little Wiki reading of people with similar problem, it turns out that no matter what Z endstop options you select in the configurator, it is going to configure you for a Z-probe.  I had to manually edit three different .g config files to remove Z-probe behavior.  I have a replacement switch (plus two spares) ordered from PrintItIndustries.

Now that I have the movement mostly figured out, I'm going to work on mounting the Duet, Panel, and routing the wiring.  After that, getting extruders, hot ends, and bed heater!

It's handy when you do the initial firmware upload...beyond that, most everything is accessible via the web interface. Note that all Gcode files uploaded (printed) via the web interface will then reside on that microSD card until it is full; again, they can be deleted via the interface.

FYI Gcode files printed from the LCD Panel microSD card will not reside on the Duet card...

1/16th stepping but due to larger diameter drive pulleys the steps/mm will be different.