Giving in and Reverting to Marlin/Ramps?

pro3d · 6 Jul 2018, 07:14

I thought I could just use the NTC3950 as normal but I understand it is more complicated

Also I wonder about the difference between M561 and G29 S2 in the GUI. Why are these to options there?

And sometimes it seems they dont clear out the compensation when when I home Z after using the GUI for these two options - Z should read the offset value but somehow reads different due to some compensation I guess?

dc42 · 6 Jul 2018, 09:16

Yes you can use a 3950 thermistor, just use parameters 100000 for the R25 value, 3950 for the B value and 0 for the C value in the configurator, or in the M305 command if you are setting that up yourself. You should be aware that as there is no resistance vs. temperature table published for those thermistors and the 3950 will be the B value at low temperatures, the temperature readings for the hot end at printing temperatures will be highly inaccurate no matter what firmware you use. That doesn't necessarily matter because you will need to experiment to find what temperature reading works for your hot end and filament anyway.
M561 and G29 S2 do exactly the same thing. M561 was implemented a long time ago. When we added G29 mesh bed compensation, we included G29 S2 because it is easier to remember than M561.

HTH David

JoergS5 · 6 Jul 2018, 09:16

This post is deleted!

pro3d · 6 Jul 2018, 10:26

@dc42

Thanks. I guess I need to read up on thermistors and check what this PT1000 thing is

Here is a link to a table for the 100K NTC3950. (I think it is table 11 in Marlin)
https://cae2100.wordpress.com/2014/03/08/beta3950-thermistor-table-for-marlin/

I still wonder why we have two options to clear the bed comp in the gui but I guess that is for the GUI developer to answer

Anyway it seems it does not clear the table all the time but I might be doing something wrong or the BL Touch is playing me

Thanks for trying to help out. I was just not aware of what a noob I was transferring to another platform so took some things for granted

dc42 · 6 Jul 2018, 11:53

That Marlin thermistor table assumes that the B value of 3950 is constant at all temperatures. It will be OK for a bed thermistor but likely to be rather inaccurate at extrusion temperatures. If you want accurate temperatures, you should use a thermistor for which the manufacturer publishes a resistance vs temperature table, or a PT100 or PT1000 or other better temperature sensor.

You can replicate that table by setting B3950 C0 in the M305 command for that heater.

Does DWC provide separate options for running M561 and G29 S2? I am on vacation so I can't check. If it does, then I agree that it shouldn't.

DjDemonD · 7 Jun 2018, 12:48

I take your point @pro3d that if you want a simple controller, then marlin running on one of the plethora of cheap controllers that exist now, is probably a simpler and cheaper solution. I have one machine still running on arduino/ramps and marlin (3 year old version at that) because it just works. I agree to some extent that if I was an OEM, it might be easier to just send a hex file to customers when I updated the firmware on their machines. It seems to work for Creality etc.

Duet is a product aimed at those who want to utilise a broad array of very useful features but not everyone needs them all (or even most of them), if the machine they are operating is fairly simple. I have a cr10 and wouldn't bother with a duet upgrade as it works out of the box. However my delta is complex and my corexy a platform for developing sensors, so the feature rich landscape with duet works there. I can't see an easy way to have a simple mode and an advanced mode, but maybe this is the way to go.

T3P3Tony · 7 Jun 2018, 13:49

@pro3d those two options are to disable two different functions

"Disable Bed Compensation"

and "Disable Mesh Grid Compensation"

Bed compensation is G32, normally used now for autolevelling the bed using two , 3 or 4 independent Z stepper motors (so the concept of disabling it does not make much sense any more). Also used on delta printers for delta calibration.

Mesh Grid Compensation is what you are using (from your other post).

pro3d · 6 Jul 2018, 14:03

@t3p3tony

Ok but then remains one question as I was told M561 does the same as G29 S2.

Are you now saying that "Disable Bed Comp"(M561) has a different function than "disable mesh grid comp"(G29 S2)?

This is what the GUI tells me they are anyway and that notation in the GUI might be wrong

But from what I now understand I should stick to G29 S2 in any .g file? If just one Z lift that is

T3P3Tony · 7 Jun 2018, 14:24

@pro3d ahh good spot. I must be getting mixed up with the behaviour on the delta with G32. I just checked on my IDEX printer and the diable runs M561, and the other runs G29 S2.

I will ask @chrishamm why we have the same option twice.

JoduWei · 7 Jun 2018, 17:45

@pro3d said in Giving in and Reverting to Marlin/Ramps?:

@joergs5 It used to be good before I converted to Duet. Now it seems like a bad probe...

Same here... My BLTouch is useless now.

Phaedrux · 6 Jul 2018, 18:26

@joduwei said in Giving in and Reverting to Marlin/Ramps?:

@pro3d said in Giving in and Reverting to Marlin/Ramps?:

@joergs5 It used to be good before I converted to Duet. Now it seems like a bad probe...

Same here... My BLTouch is useless now.

I'd be interested in digging into why that is. I've used a couple different ones now from original to knock off to the newest version and they are not all created equally but all did work eventually. With the v2 smart probe I'm getting better results than ever, so it's definitely possible.

JoduWei · 6 Jul 2018, 18:32

@phaedrux

Idk whats the reason. Mine is a geniune v1 smart.
Even with all heaters off (and cold) Mesh compensation errors out at a random. Homing Z is gambling, have to baby step almost every time.

Phaedrux · 6 Jul 2018, 19:00

@joduwei said in Giving in and Reverting to Marlin/Ramps?:

@phaedrux

Idk whats the reason. Mine is a geniune v1 smart.
Even with all heaters off (and cold) Mesh compensation errors out at a random. Homing Z is gambling, have to baby step almost every time.

Not to hijack the thread, but have you tried cleaning the pin? My original V1 was sticky from the factory and was very inconsistent. After cleaning it was much much better.

pro3d · 6 Jul 2018, 19:30

The main reason for my complaints in the OP are the terrible prints it puts out and all the macro world I dont want a part of but guess I am stuck with if using D3D/RRFW

I could probably live with some thermistor issue and the bad probing results if there was some prints even close to something useful I could send out to customers

When I first configured this printer with Marlin on a simple Ramps board with drv8825s the first time and just calibrating the extruder steps I never looked back except upgrading the board and electronics to 24V controller/12V Fans with SSR and AC Heater

I know that I am probably doing something very wrong in configuring or that my use of clown components are the reason why I getting so bad prints. It could just be the whole NTC 100K 3950 thermistor that throws of the temperature and make flow inconsistent

It might also be the use of relative extrusion I dont understand as I never used this before. It might also be Cura 3,4 not liking to slice in relative mode

It is just that I have been using this equipment for years no problem and I am by no means a noob in the calibrating world. I know I have a lot to learn though as I dont even know what a PT1000 is

There is just to many questions and few answers and the prints are behind. It is kind of curios that as a intermediate+ (at the least) printer designer and user I run into all these problems but I will no doubt learn from it and come out stronger

Thanks for trying to motivate me Have a nice weekend