Ender 5 S1 Auto Bed Leveling Fix

After struggling with trying to get my Auto bed levelling working on my E5S1 I had given up and just removed it from my initiation gcode and gone back to manual levelling with good results.  

However I started noticing the issue popping up more and more and it became clear it was because of a design flaw that exasperated the issue of a slightly twisted x axis caused by having a larger Y offset on the CR Touch.

https://www.reddit.com/r/Ender5S1/comments/10ow7k8/twisted_x_extrusion_on_ender_5_s1/

https://www.reddit.com/r/ender5/comments/111owjf/ender_5s1_autoleveling_issues/

So I thought I would knock up a quick mount to move the CR touch to a Zero Y Offset position.

(Process below was using Sonic Pad, I am working to get some stock marlin instructions also).

So I deleted the existing mesh in moonraker (which I found the easiest to use) and after a reset, I did a z offset process and a manual level.  Then I ran the auto bed levelling with the default position and then cleared it again, moved the CR touch to the new mount, redid the Z offset, updated the printer.cfg (detail below) and ran the bed levelling again and got the below improved changes.  Whilst still not perfectly level, I was then able to print a VERY smooth first layer test print and am certain my issues have been sorted.



So how to get that to happen for you?

Before you start, I'd suggest to clear any existing mesh in moonraker, save and restart klipper/sonic pad.  Do a fresh Z offset calibration, heat the bed and go through the manual levelling.  Once done, run a auto bed level and screenshot the result similar to above.  This will allow you to know the difference or improvement from this mod.  IN THE MEANTIME DO NOT ADJUST MANUAL LEVELLING.

As for position of the new mount, the right hand side looked like it would work the best as it meant no loss of print area and less likely for anyone to have a crash.  It could conveniently use the holes in the extruder where I had been mounting the sonic pad sensor.  So I have also built the sensor mount into my design.



What it did mean was that I needed to either find a longer CR touch cable that would reach now or what I did in the end was purchase this and make myself up an extension adapter https://www.amazon.com.au/dp/B08RMQP6YP?psc=1&ref=ppx_yo2ov_dt_b_product_details

For anyone having trouble sourcing.  You need ~15-20cm total cable length depending on how creative you are with your routing.  Search for a JST 1.25mm pitch 5 pin cable and there are many results available also.  i.e. this one from ebay.
 

I also needed some M3 bolts that I had already and I used some m3x6mm heatset inserts for the CR touch to screw to, but you could also just use some nuts on my design.

What this mount does is move the CR touch offset from 0,45 across to 45,0.  Once you move the CR touch, to get the printer to use this right you need to update a couple spots in the printer.cfg file (once again easily done via moonraker)

Save and restart Klipper.

Also if you havent done it yet, delete out the default mesh you might alreayd have, and once again save and restart Klipper.

Once that's done BE SURE TO REDO Z OFFSET CALIBRATION.  The new mount is very close to the old position but it would be identical due to heatset installs etc etc etc.

Then you should be right to run a new auto bed level and bing bango, hopefully you see some good results.

I have been working on this for a week or so but this morning I saw one of my favourite youtubers cover this same issue on his channel with his own similar solution.  Please check it out Nathan Builds Robots Ender 5 S1 Upgrades

I have a few other Ender 5 S1 models up https://www.printables.com/social/553376-kevin-cooper/models that might be worth checking out.  I think I also will work on a left side hotend cover attached CR mount that hopefully can use the original cable but I think it might be tight.