possible to disable/ramp-down bed compensation?
Hi,
Is there a way to tell slic3r or the firmware to either not do the z compensation for warped beds or maybe to have the compensation ramp down over the first mm or 3 of the print so that it over/under-extrudes instead of changing z?
I'm printing a hose adapter - mostly just a cylinder with a few diameter changes - and can see that it's carrying the bed errors all the way through the print via varying Z on every layer. It seems like it might be better to vary the extrusion rate over bed errors by, say, 1/20th of the error for the first 20 layers. I'd like the top of my object to be flat, not a mirror of my bed errors.
A less-desirable choice would be to turn off the compensation and do a raft. I think that'd make both the top and bottom flat.
Is there any way to do these things?
Thanks!
MK2.5 + v1 MMU and latest firmware.
edit: oops.. posted in the MK3 forum.. I think it applies to both machines, though.
Re: possible to disable/ramp-down bed compensation?
it's an interesting question. Is your part actually not flat on the top? measurable amount?
I have followed another member's example and installed a mod that allowed me to 'flatten' the bed and get rid of the compensation by virtue of the measurements coming out pretty flat. Before I did that I lowered the rear attachment point of the right Y axis rod because I observed that most of the bed error was from y axis rods that are not parallel.
I did this because I was doing experiments with 1-layer prints (they turn out like a sheet of paper) and I thought the print artifacts were caused by the compensation but it turned out I got the exact same results regardless.
I have a theory that the bed compensation could be more about compensating for deflection of the extruder carriage and the bed. If this is true you would want the compensation the whole way through - but I have not proved this yet.
G80 is the command for mesh bed level. I wonder... if you leave that from the startup code would you get the desired change? You may have to cold-boot the printer to clear the stored values.
Re: possible to disable/ramp-down bed compensation?
> Is your part actually not flat on the top? measurable amount?
Dunno - I have not actually printed something with a flat top. I can see the Z axes moving almost constantly when printing, though. I assume it will do that all the way up to the top.
Thanks for the info. I'll look into messing with G80.
Re: possible to disable/ramp-down bed compensation?
Hi,
Is there a way to tell slic3r or the firmware to either not do the z compensation for warped beds or maybe to have the compensation ramp down over the first mm or 3 of the print so that it over/under-extrudes instead of changing z?
Someome on the forum posted it a while ago, I added it to my custom build: https://github.com/koenkooi/Prusa-Firmware/commit/c1750da6d058b96347804211eece7e23ef5b29a1
The fade stops after 1.2mm.