After changing the design of the cutter holder to match the Husky utility blade profile, I was starting to think about a better way to hold the blade in place & be able to change it without taking 1 or 2 screws out. In the middle of the night I realized a binder clip might work for this. If I make some recesses in the plastic on the bottom & the top cover this might work well. Here is a photo of what I had in mind. I will have to adjust the cover & holder to match the clip better. This clip is 1.5" wide. Looks like I will have to clip it to the side or along the top sharp edge of the blade instead of the top as I don’t have enough clearance on top. I might be able to design a plastic clip, but would not be as strong as the metal binder clips.
I came up with a clip clamp along this idea which looks like it will work. I need to make the diameter a little bigger to get more strength, but 1st test seemed pretty good. I made it 8 sided so it would print well. Here are 2 pictures & a dimensioned part. I made the design with 5 customizable dimensions. I have not put it on thingiverse yet. I am going to use this idea for something else also, which is why I made the 2 sides individual variable lengths.
I got a little sidetracked & went a little overboard with customizing variables for this little clip clamp. Hope I did not get too far off topic here. I am not sure it will be strong enough to replace the screws in this design, but should have some other uses. Here is an example image showing most of the possible variations in the design. The part can be found thingiverse & also opened in the customizer: https://www.thingiverse.com/thing:2726864
james …
thank you very much for the work you have done…
I want to try your project but I have a problem …I commented on the two lines of the firmware
//#define PREVENT_LENGTHY_EXTRUDE
//#define EXTRUDE_MAXLENGTH 200
I can not make 1 full turn at the cutter…
I entered the order 103.xx steps per mm for E …I’m using the basic firmware with a 1 degree temperature…
when I try the g1 e3600 command (10 full turns) and checking that 10 turns happen and the final angle matches the initial angle,
it always runs without stopping…
you can give me some more information??
thank you so much james
I guess you hit the quote button on a google-translated page? I didn’t know it would do that.
I think you’re saying: G1 E3600: It continues forever, and doesn’t stop. Is that right?
Can you try something smaller?
G1 E4
or
G1 E360
I think the steps/mm is way off. It really should be steps/unit, and in this case unit is degrees. If you have the drv8825 driver, and all three jumpers installed, then it should be 200 * 32 / 360 = 17.777 steps/degree. If you have the a4988 driver, or some other jumper configuration, then it should be even smaller (with 1/16 steps, it would be half that). This is also assuming you have a 200 steps/revolution stepper.
thank you so much…
the problem was in the formula to calculate the engine steps
forgive me for the scandalous English
No problem. I’m an engineer. I work with many native English speakers who have a hard time with English. 
Hello
I can not get the firmware to work in degrees…
use as step dvr 8825 I worked with step 0 to 32 step with the same result! I used the formula 200 * step/360 = …
when I try to give the command G1 E360 the knife always turns!!
I followed the tutorial from the site: https://www.thingiverse.com/thing:2624654
I can not understand how you can have 103.XX steps …I followed everything in step by step his tutorial…
thanks to those who can explain me…
Can you try something smaller until it actually stops?
G1 E1.0
my configuration is: nema 17 1.8 degrees 200 steps/revolution stepper jumpers 1/16 steps…
I inserted in the firmware :#define DEFAULT_AXIS_STEPS_PER_UNIT { 200, 200, 800, 8.8888888889 } //MPCNC
200 * 16 / 360 = 8.8888888889
I try to give the command G1 E1.0 always runs more than 1 turn…
I have to be able to take a ride with the command G1 E360
(james)which configuration can have him to have 103.xx steps
maybe he modified something in the unspecified firmware…
thank you
The value is steps/unit and James used 1/10rad for his unit, at some point. I’m pretty sure that’s where that came from. The 103 doesn’t match with the E3600, so that’s a mistake in the TV page.
At least the stepper is stopping, so you can measure it. Something is still not making sense. Try the M92 command to change it:
http://marlinfw.org/docs/gcode/M092.html
You can retrieve the current setting with M503 and you can save them to eeprom with M500 (which isn’t needed for testing, just for power cycle).
So I would try:
G90
G1 E1.0 F30
M92 E8.88
G1 E2.0 F30
That should try your current setting and then change it and try the second one (the second one should be incredibly small).
Hey, back from holidays.
I have just double checked also my eeprom setting, and I have 102.4 steps/mm for E, and G1 E360 does one full turn…honest. I can’t explain it.
I agree with the formula of 200 * steps / 360 in theory. I checked the spec of my E stepper: also 200 steps per revolution. I don’t think I changed anything in the firmware other than the two lines you have to comment, but it really shouldn’t matter if I had. Should be able to control this from eeprom and the driver jumpers only. I have also checked the driver jumpers on mine. DRV8825 with all jumpers, so 1/32 stepping.
Maybe in Maong’s case the firmware is not responding to the changes of E steps/mm in configuration.h, because it’s reading the value from eeprom. I always make changes in eeprom. Either gcode or Alt+E in Repetier host. Did you try Jeff’s suggestion? I’m guessing if you start with an M500 it will show that the steps/mm for E is not what you are setting.
What!?! That’s off by about a factor of 6 (5.76). This is very strange. Where could we be making a 6x mistake? 2pi? Sqrt(36)? This is going to bother me all day…
Is it because it’s the extruder? Do you have some flow rate set?
Ho messo 3 ponticelli e 32 gradini …
Ho eseguito il comando
G90
G1 E1.0 F30
M92 E8.88
G1 E2.0 F30
M503
M500
Esegue i comandi lentamente ma non corrispondono
Ho provato di tutto
mia configurazione.h:
Configuration.h (57.5 KB)
What do you mean, they do not match? How much did it move the first move and the second move? Each move should take two seconds.
I did your test…
in both cases they stop at the same point…every move requires a lot more than two seconds…
surely there is some setting in the firmware to be fixed
The DEFAULT_MAX_FEEDRATE is set to 1 deg/sec, that’s not very high. Maybe set that to 90. The acceleration is enormous, maybe set that to 180.
The F30 should be 30degrees/min, and it’s trying to move only one degree, so that should be 2 seconds. Something is wrong.
It’s very hard to debug from here. The configuration.h is very long… You haven’t told me how long it takes, how far it goes, or wether changing the setting in the middle makes any difference.
thank you tomorrow I try how you say … even if I did not understand the importance of the DEFAULT_MAX_FEEDRATE …