I have bought this leadscrew:
http://www.banggood.com/3D-Printer-300mm-Lead-Screw-Z-Axis-8mm-Screw-Pitch-p-980650.html
It says it has a pitch of 2 mm, but i think that is not correct.
with a caliper i measure 2.5mm between 1 thread.
so i have changed the steps/mm to 1280.
but when i push the 1mm button up in repetierhost, the hotens moves 2.55mm up
what am i doing wrong?, and what are the correct settings
I did see in Repetier Version 0.95F under tools there is a lead screw calculator.
You might try that.
I have never used it so this is all of the help I can offer.
Yes i know, and i used it also.
When i choose a TR8 x2mm
i get a value of 1600 steps.
when i send this to the eeprom, and move the extruder 1mm up, the distance travelled is much more then a mm.
[quote=“dutchronnie”][quote]
I did see in Repetier Version 0.95F under tools there is a lead screw calculator.
You might try that.
[/quote]
Yes i know, and i used it also.
When i choose a TR8 x2mm
i get a value of 1600 steps.
when i send this to the eeprom, and move the extruder 1mm up, the distance travelled is much more then a mm.[/quote]
Looks like the screw has multiple threads, can this be?
If, so, the pich would be way more than 2mm.
Look here for the prusa calculator, it will allow you to calculate custom thread piches (leads).
prusaprinters.org/calculator/
No, the screw has no multiple threads.
I have bbeen measuring again, and after all i concluded that it is a TR8x2mm.
first i have measured a single thread, now i have mesured 10 threads and i was 20mm.
when i calculate the steps in the prusa calculator, i get a value of 1600.
this value i put in the firmware: M92 Z1600.00
save M500
but then, when i move up the extruder in repetier with 1mm, the extruder moves more than 1 mm.
the exact amount i wil try to measure this evening. but it was far more than 1mm.
when i put back my old leadscrew, and enter the value: 2133.33
saved it, and the movement was good.
edit:
Strange, i don’t understand.
I have measured again. 1mm = 4 mm
so when i changed the Z to 400
then the travel is 1mm
How is this possible, it is not what the calculator is saying, and is this leasscrew accurate enough with a setting of 400 ?
[quote=“dutchronnie”]No, the screw has no multiple threads.
I have bbeen measuring again, and after all i concluded that it is a TR8x2mm.
first i have measured a single thread, now i have mesured 10 threads and i was 20mm.
when i calculate the steps in the prusa calculator, i get a value of 1600.
this value i put in the firmware: M92 Z1600.00
save M500
but then, when i move up the extruder in repetier with 1mm, the extruder moves more than 1 mm.
the exact amount i wil try to measure this evening. but it was far more than 1mm.
when i put back my old leadscrew, and enter the value: 2133.33
saved it, and the movement was good.
edit:
Strange, i don’t understand.
I have measured again. 1mm = 4 mm
so when i changed the Z to 400
then the travel is 1mm
How is this possible, it is not what the calculator is saying, and is this leasscrew accurate enough with a setting of 400 ?[/quote]
From your writing i’m almost sure you have a multi-thread spindle. 1mm->4mm makes me believe you have a 8x4 (or 5?) screw.
Internet pictures can be misleading. Can you take a picture of the end of the leadscrew you have and post it?
i am not able to make a picture of the end of the leadscrew, becaus i have already built it in the printer.
but it is exact as in the pictures on banggood. http://www.banggood.com/3D-Printer-300mm-Lead-Screw-Z-Axis-8mm-Screw-Pitch-p-980650.html
maybe it is a multiple thread screw, but the distance between 2 threads is 2mm.
the printing results are very good with this screw.
i have already calibrated the screw, so the 400 setting is changed to 403.22, or something like that.
i am not able to make a picture of the end of the leadscrew, becaus i have already built it in the printer.
but it is exact as in the pictures on banggood. http://www.banggood.com/3D-Printer-300mm-Lead-Screw-Z-Axis-8mm-Screw-Pitch-p-980650.html
maybe it is a multiple thread screw, but the distance between 2 threads is 2mm.
the printing results are very good with this screw.
i have already calibrated the screw, so the 400 setting is changed to 403.22, or something like that.
Then the screw is definately mutistart-threaded. (helix thread)
I think it has 3 thead starts, as i can tell from the pictures.
The specs on the page indicate a pitch of 8mm/rev.
This gives 400 steps/mm.
It’s right there is the spec.
Pitch is 2mm, but lead is 8mm.
Therefore it it must be a 4 start thread.
yep!
Ok, so the information on banggood is not right.
But the leadscrew is working well now the settings are good.
does it matter if the leadscrew makes this big steps?
Banggood says :
3D Printer T8 300mm Z Axis Lead Screw [color=#FF0000]8mm[/color] Screw Pitch
Although they must have really meant lead.
The pitch between the threads is 2mm but the lead (movement length) is 8mm per revolution.
So no really wrong specs.
If you have 400 steps per mm it will give you a 400th mm movement length per step.
Should be enough resolution. Just make sure the axis runs smooth and doesn’t cause lost steps
because of the high lead.
Copied and pasted straight off the Banggood product page…
3D Printer T8 300mm Z Axis Lead Screw 8mm Screw Pitch
Specifications:
Material: 304 stainless steel
Diameter: 8mm
Length: 300mm
Pitch: 2mm
Lead of thread: 8mm
Length: 300mm
[quote=“ichbinsnur”]Banggood says :
3D Printer T8 300mm Z Axis Lead Screw [color=#FF0000]8mm[/color] Screw Pitch
Although they must have really meant lead.
The pitch between the threads is 2mm but the lead (movement length) is 8mm per revolution.
So no really wrong specs.
If you have 400 steps per mm it will give you a 400th mm movement length per step.
Should be enough resolution. Just make sure the axis runs smooth and doesn’t cause lost steps
because of the high lead.[/quote]
I have the same leadscrew, it works well with 400 steps/mm
[quote]Material: 304 stainless steel
Diameter: 8mm
Length: 300mm
[color=#FF0000]Pitch: 2mm[/color]
Lead of thread: 8mm
Length: 300mm[/quote]
I only saw this pitch information, that is why i thought it was a 2mm movement in 1 turn.
Doesn’t matter, it works really good.
better as a TR8x1,5, which i have tried also.
I have ordered the leadscrew with 2 nuts, and maked with spring a antibacklash nut.
[quote=“dutchronnie”][quote]Material: 304 stainless steel
Diameter: 8mm
Length: 300mm
[color=#FF0000]Pitch: 2mm[/color]
Lead of thread: 8mm
Length: 300mm[/quote]
I only saw this pitch information, that is why i thought it was a 2mm movement in 1 turn.
Doesn’t matter, it works really good.
better as a TR8x1,5, which i have tried also.
I have ordered the leadscrew with 2 nuts, and maked with spring a antibacklash nut.[/quote]
Is the antibacklash necessary? The load is always in the same direction, by gravity.
I don’t know if it is neccesary, but in my opinion does ik make the z some smoother.
maybe i am wrong, but it can’t be wrong to use it