Info on NEMA 17 5.5 kg.cm

[The Gresley Luthier]

Hi All.

I have been away due to illness for a very long time, I'm ok now so I am resurrecting my CNC router project.

Can anyone help me please, can the Nema 17 - 5.5kg.cm cut rosewood (Guitar Fretboard Slotting) with slow, shallow passes, I have tried to calculate using the calculators on the net, but at 77 y.o. it's all Gobbledygook to me.

Many Thanks in Anticipation.

Regards.
Ray

[JohnHaine]

Very hard to answer as it will depend on the friction in the slides and leadscrews, and the gearing between motor and screws, if any. More details please!

[The Gresley Luthier]

Thanks for getting back to me.

I know that NEMA 23's would be the answer, but that costs money, if i do not get things right. I am a 77 y.o. pensioner, so you can imagine i am on a very tight budget. My apologies if you already know this. A guitar fretboard as anything from 20 to 22 frets usually. Each Fret as a unique spacing dimension, the gaps between the frets diminishes when you go up the fretboard. I wish to build a CNC with one axis ("X" axis) so i can enter the spacing details into a controller, which will push the Router Sled to the correct position, where i can lock the X axis into position, and manually operate the "Y" axis to cut the FRET SLOTS.
The Router spindle and "Y" axis rails & bearings weigh about 4.8 kgs. If you need more info please ask me again.
Regards
Ray

[JohnHaine]

Understood.

A suggestion: rather than use CNC which would involve you in steppers, leadscrews, drivers, power supply, PC etc, why not just have a digital readout scale for the X axis? That would give at least the same accuracy, be cheaper, and probably easier to make. And no need for any G-codery.

You can get a single axis DRO readout and 32" scale for £119 on offer at the moment:

https://woodworkersworkshop.co.uk/pr...BoCR9YQAvD_BwE

Self contained, no PSU needed (runs off battery).

[The Gresley Luthier]

Thanks for the suggestion, I have already considered this as I have used them on a small hobby Milling machine. My problem is, I already have the Stepper motors, so until I can prove to her indoors who must be obeyed, they will not work, she would divorce me for spending that kind of money. If I can confirm they will do the job I will need to spend on Ball screws and Ball Nuts but that should please her.

Again, thanks for the suggestion.

Ray