coupling Nema 23 stepper to X mill X axis spindle

[John Rudd]

I have just received a stepper motor from ARC for my X2 clone with the intention of adding it to power the X axis...( I decided against the wiper motor approach, it was too power hungry... )

I could just cobble a coupling that mates with the 6mm shaft of the stepper and mate that to the 10mm shaft of the X axis spindle or is there a better way?

So I'm looking for recommendations on 'splicing' the two shafts together..Keeping it simple is my main aim...

[raynerd]

Hi John

I`m currently building a controller to do exactly the same thing, an x-axis power feed. The details for the stand alone x-axis controller unit but also my design of coupling the motor to the X-axis is shown below:
http://madmodder.net/index.php?topic=2417.0  This is the thread – it went a bit off topic but it getting back to the x-axis controller on the latest posts.

The pictures are here:
 

This is the part that connects the lead screw of the x-axis to the motor shaft. The thin end will attach to the oldham coupling


This is looking into the end of the fat end. The bar going through the bore locks into the notch at the end of the lead screw and engages it.



Both parts held into position - the gap is the space for the Oldham coupling and spacer to sit.


I`ve since got the Oldham coupling and fitted that. I was actually taking pictures in the workshop of it all together but haven`t had time to put it online and update yet.

How are you going to power/run the motor, Mach3 or an independent controller?

[John Rudd]

Chris, Yup saw that nice idea...

Trouble is my mill has handles either end of the table therefore there are thrust bearings at either end...

Also is there any harm in directly coupling the motor to the X spindle? If the motor is de-energised and cranked by the handle at the opposite end will it harm the motor or do I need to have some form of drive disconnect?

My original intent was to drive the spindle via a dog clutch that could be engaged/disengaged when required/not req'd.

I bought a stepper driver kit from Quasar to see how the motor drives my table..

Dont think cnc is for me atm...

I'm surprised by the size of the motor...bigger than I thought..

I may build a cnc foam cutter for making wings for my R/C models yet....

[raynerd]

John, I`m certainly no expert, as you know I`m very much learning but I`ve actually been visiting a friend who has built a CNC router out of MDF!!! It is amazing, works a treat and you would be blown away by its capability. He has used V-carve Pro to cut an amazing door sign and also some nice parts for a plastic plane. Obviously the limitation is that with it being MDF it has not got the strength and can only cut wood and ally. He actually has used proper slides and slide bearings and an achne lead screw in each axis and the stepper motors and drivers are nearly a good few hundred alone. He is about to strip it down and rebuild in ally sides. It really blew me away!

Anyway, regarding driving the motor directly to the spindle, this is what all those "in the know" seem to do over on CNC zone. If it is a copy of the X2 style machine, I would like to see a picture if you have one. What is the use for the handle at the other side and if it is of limited use I would be tempted to remove one of them and couple the motor on that side. Use an Oldham coupling to give you some leaway in alignment. Regarding your question about driving the motor when off, no there is absolutely no resistance and no damage can be done to the motor - you don`t have to disconnect. That is the beauty of the stepper motor, when they are powered down it is as though they are not even there!

I don`t see anyway your going to easily couple the motor without removing one of the handles....

Regarding CNC not being for you, I started to CNC my little lathe after only 4-5 months in machining. I`m sure many on here would call me an idot but I`ve learnt a lot from playing about and I`m learning all the time. I think the biggest problem with CNC is the equipment involved and the various settings that are possible - best thing is to do as you have, buy the motor the driver, plug it in and give it a go.

First thing I did was load up Mach3 and couple my motor and driver and just get it to jog without being attached to anything. Once it is jogging you can then couple it to your machine and your up and running.

Let me know how it goes and hopefully when I get my little X-axis controller running, if it is any good then it should only cost about £15 to make them .... if you get it up and running I may send you one over to test. Have you put your Quasar driver together yet? I looked at those and nearly bought one but for the extra I decided on a MotionControl and ArcEuro.

[HS93]

you could always belt drive it and leave the handels on, similar to this on my X1

http://madmodder.net/index.php?topic=486.msg1583#msg1583

Peter

[raynerd]

Peter, excellent job. I`m going to have to belt drive my Y-axis next so thanks for the link.

Chris

[John Rudd]

Chris,

I've almost built the stepper controller, just need to install the fets(after adding a heatsink)

Here's a picture of my mill( albeit mine is a white/cream colour) showing both hand wheels..

[HS93]

that mill is realy easy to go to belt drive, just remove one of the plates replace with a ally mount with bearing and thrust washers and make up the difference with a toothed gear, slip belt of when not in use if you want, I also use Arc euro handels that fold for saftey when milling.

Peter