What I did on my Anycubic was that I stuck the carriage spacers underneath and didn't worry about it. Worked fine. The carriage is rarely near either pulley unless homed; during prints it's usually much closer to the middle of the rails.
The smart effector is such a win that noone should hesitate to install it if possible.
Just rebuilt my kossel with larger frame and bed. Now the only parts left from the original Anycubic are the linear rails. Had to build my own effector arms due to not finding any long enough for the new size. (Thanks, David, for the pointer on your blog to the video on cutting carbon tubing!) Anyway, apparently I've gone over the limit of the inertia in the system with these new arms. Old arms were 288mm/4mm, these are 495mm/8mm so quite a bit larger. Using smart effector with mag balls, same as before. Now, when the motors are turned off, the effector falls down, where before it would not. Other than not turning the motors off at the end of a print, any good way to keep the effector from falling onto the print? Got a melted dent in a part from the nozzle falling onto it just now.
Anyone have suggestions on how to fix this?
Other than that, the Duet controller made the change pretty painless--just update a few values in config.g and recalibrate, ready to go!
Thanks in advance for any help or comments.
How big, what plastics are you printing with?
I'm currently using a CHPOWER Creality Magnetic build surface from Amazon. Very flat, prints PLA very well. Downsides: 300x300 mm only (could trim smaller), max 70C temp. Have not tried it with PETG, which I usually like to print with 90C bed temp.
I was looking at the magnetic beds sold by Geckotek, but got an EZ-Stik Hot print surface to try. At first, was really liking it, but started having problems with the filament not sticking after only about 15-20 prints. I think their magnetic beds all come with that surface applied.
Still having the calibration issues I saw on RC4. This is on my delta with smart effector. The calibration seems to oscillate between a few different heights, never converges on one particular height. Also still had the issue with the effector triggering early, had to leave it with sensitivity set to 128 instead of default. After doing that, and saving (with M500) a G32 result that seemed kind of correct and a following G29, was attempting to recalibrate the offset from 0 for the Z probe in config.g using baby stepping to get a feel for how far off it currently was. Baby stepping appears to be very broken. Was using the Due to set the baby step for a 0.2mm patch print, and then measure the actual thickness of the patch with a micrometer. Setting the baby step while the bed is heating does not seem to actually change the thickness--though it does change the baby step setting readout. Pushing the baby step up/down buttons while the extruder is heating (following the bed heat) do not immediately change the reading, but once the extruder is up to temp, the readout does change appropriately. Again, though, the actual print does not seem to change. Once the print has actually started extruding, the baby step does seem to change when the up/down buttons are pushed, but they may or may not match the reading.
Went back to 2.02, G32 converged in about 5-6 iterations. Haven't backed off the effector sensitivity yet to try that.
Had some odd leveling behavior on my delta.
Had a quite hard time getting G32 to converge on a particular height, but finally did. Then noticed several aborted probing points when running G29, followed by reports of 4.x mm max height error. After increasing the force needed by the smart effector from default to 128, got a kinda good height map. Now I have to edit the deflection setting in config.g--I had to add +0.15 mm baby step to get first layer correct. Everything was working quite well prior to upgrade.
What I did on my Anycubic was that I stuck the carriage spacers underneath and didn't worry about it. Worked fine. The carriage is rarely near either pulley unless homed; during prints it's usually much closer to the middle of the rails.
The smart effector is such a win that noone should hesitate to install it if possible.
Thanks, those are all great suggestions!
Back when I was building my delta, I made it large enough to print 400mm round. For monetary reasons, only put in a 300mm round bed. Recently, broke the bed glass and had to replace it, but the only reasonably affordable bed I could find was a square 300mm x 300mm. I think the rest of the printer is capable of printing to the entire bed surface, but it's configured still as 300mm round, so I can't use the corners. Any way to tell the Duet 2 I have a delta with a square bed? Thanks in advance!
I run PLA at 215/210. Need a bit better cooling, but it comes out OK if I don't print thin spires or the like. Using a small stepper for the nimble. Had problems with losing steps with a regular sized stepper.
Here's my settings:
M92 X160 Y160 Z160 E2600 ; Set steps per mm
M566 X1200 Y1200 Z1200 E100 ; Set maximum instantaneous speed changes (mm/min)
M203 X22000 Y22000 Z22000 E6000 ; Set maximum speeds (mm/min)
M201 X6000 Y6000 Z6000 E1500 ; Set accelerations (mm/s^2)
M906 X1000 Y1000 Z1000 E750 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout
M207 S2.0 F1500 T900 Z0.5 ; Set FW retraction length and speed
M572 D0 S0.10 ; Set pressure advance
I too started with an Anycubic Linear plus. The only original parts on the printer now are the linear rails. I was actually considering putting the leftover parts back together to have a third printer, but then I realized I'd just want to re-upgrade that into a duplicate of my second printer.
eventually I'll get off my butt to machine a replacement.
PRINT a replacement. 
unhappy with the filament extruder drive assembly
Look at Zesty Nimble. High initial cost, but dead reliable.
For your bed issues, I find clamps printed in PETG work quite well up to ~100C.
I also vote for option 3. Moving to the Duet and 24V and 0.9 degree steppers and...(it goes on) was a great thing for the Anycubic Kossel I had, but for my Prusa, adding octoprint took away 99% of the headache. It retains your possibility of selling the printer as is later, as well.