SIEG X2 Y Axis Power Feed Idea

[MetalMuncher]

Hi folks.

I would like to add a power feed to the Y axis on my Speedway Mini-Mill (SIEG X2 style) while retaining the hand crank. So, I have an idea. Since I had a DRO, I don' use the indicator collars on the cranks. If I remove the indicator collar on the Y Axis handwheel, I would have a nice place to put a pulley that would need a 20mm bore, and be no more than 11mm wide and 50mm OD. I was hoping to find such a beast in a notched timing pulley style, but several hours of searching online have come up with nothing at all even close.

Any of you know where I could find such a pulley? The 20mm bore could possibly be made smaller if I could manage to turn down the handwheel in that area by putting it in my mini-lathe. The shaft of the Y axis leadscrew is only 10mm O.D. so I guess there would be some amount of stock I could remove to use a slightly smaller bore in the pulley. The 11mm width I mentioned could possibly also be increased if I machined down the mating portion of the leadscrew support facing the handwheel to some degree. I'd have to buy another one of those to do the machining, as I only have this one mill, but I would do so if needed.

The 50mm maximum OD is not very forgiving. I have a scale running along the leading edge of the table for the X Axis on the DRO, and so I need clearance for the scale's body section as the table moves toward me on the Y axis.

I suppose adding a jack shaft to the Y axis leadscrew might allow me some wiggle room on that aspect.....maybe. But I don't want to have the handwheel sticking too far toward me.

My plan if I could find such a pulley is to use another of the X Axis power drive units like I already have mounted, (like sold my Little Machine Shop and Micro-Mark) to drive the Y axis using a notched belt, with the power unit to the right of the handwheel. The left side is occupied with part of my Y axis DRO scale mount.

I thought about trying to put a stepper motor on it with a CNC type controller, but I've never seen that done while also retaining the handwheel, and it would make the handwheel stick out quite a distance if attempted, presenting the risk of my catching on it while working on other projects near the mill. Utilizing another of the X-Axis style self-contained drive and control unit would save me a lot of research and design. I just need to add it to the Y axis leadscrew somehow.

Any suggestions are welcome.

[Brass_Machine]

...
I thought about trying to put a stepper motor on it with a CNC type controller, but I've never seen that done while also retaining the handwheel, and it would make the handwheel stick out quite a distance, presenting the risk of  catching on it while working on other projects near the mill. Utilizing another of the X-Axis style self-contained drive and control unit would save me a lot of research and design. I just need to add it to the Y axis leadscrew somehow.

Any suggestions are welcome.

Fignoggle sells CNC plans that keep the handwheel where it is.



Eric

[MetalMuncher]

Hey thanks! I'll look into that right now.

[efrench]

A GT2-3mm 50 tooth gear OD would be about 47mm.  You would probably need to remove the hub and put set screws through the teeth. SDP-SI part A 6A55M030NF0912

[Swarfing]

Make sure you have a disengage of motor arrangement, as not to end up with a nice little generator to fry your electrical's if you keep the hand wheel.

[MetalMuncher]

A GT2-3mm 50 tooth gear OD would be about 47mm.  You would probably need to remove the hub and put set screws through the teeth. SDP-SI part A 6A55M030NF0912

Thanks! Putting setscrews through the teeth was my plan, as the exposed 20mm dia. surface with the collar removed from the handwheel is only 11mm wide. This one looks like I could make it work.

Am I correct in thinking it wise to use a flanged pulley on the motor, to keep the belt from wandering off the pulleys, or is that not necessary on relatively slow speed arrangements like this? I don't yet know the output shaft diameter on the motor I'll use to drive this, but the pulleys will need to be the same diameter if I use the powerfeed controller mentioned above, so there won't be a change in speed from what it produces.

[MetalMuncher]

Make sure you have a disengage of motor arrangement, as not to end up with a nice little generator to fry your electrical's if you keep the hand wheel.

Thanks! I'll keep this in mind.

[efrench]

A keyway would probably be better than the set screws.  A single flange on each pulley on opposite sides would be the minimum needed. I'd use double flanges on each unless there's a reason for using fewer.

[MetalMuncher]

A keyway would probably be better than the set screws.  A single flange on each pulley on opposite sides would be the minimum needed. I'd use double flanges on each unless there's a reason for using fewer.

Although a keyway would be nice, I am not equipped to go that route. And there is insufficent stock for that to work, with my requirements for a <50mm OD yet using a 20mm bore on the pulley. The X Axis power feed I've been using for years employs a coupling with setscrews, and it has never presented a problem. Making a small flat  for the setscrews is doable, and would help the pulley not slip on its mount.

If I can find a pulley with flanges that I can make fit on the 11mm of shaft length I have to work with I would prefer to go that route. I believe some of the notched timing belts are made rather narrow. It may be possible to use a pulley wider than 11mm but have the hub milled to only 11mm thick. I would have to do some more measuring to see what clearances I've got on either side of the proposed pulley when mounted. Also, I need to inspect the Y axis leadscrew support piece bolted to the face of the base casting. It may be thicker than absolutely necessary, allowing for removal of some stock to widen that 11mm restriction adjacent to it. It's been too long since I had the mill apart to recall how that piece is machined.

[efrench]

sdp-si has CAD drawings of the pulleys, so it should be easy to see how to modify them to fit.

[MetalMuncher]

sdp-si has CAD drawings of the pulleys, so it should be easy to see how to modify them to fit.

Thanks. I see they also have my desired diameter in a type with flanges, but no hub. That would save some milling. Hopefully I'll have time tonight to get the Y axis screw retainer off and then learn if, and how much, shaft length could be picked up for placement of the pulley if I milled away some of the retainer. What would really be cool is if I could simply remove the inner collar of the handwheel as well as some of the retainer, to fit a pulley on the 10mm shaft that would be exposed. Might even be able to take advantage of the end of the keyway it has for the handwheel. If I could get a pulley with a matching keyway in it for a 10mm bore.

I wonder if anyone has ever used rounded keystock in such an application. I don't have a way to cut a square key channel, but certainly could do a half-round in its place.

[efrench]

Just lock the Y axis and use the X axis to mill the keyway in the shaft.  Use an endmill to remove most of the keyway in the pulley and finish with a file.

[MetalMuncher]

Just lock the Y axis and use the X axis to mill the keyway in the shaft.  Use an endmill to remove most of the keyway in the pulley and finish with a file.

By golly that would work! Thanks!

I took the Y axis retainer off tonight, and more closely measured the area where it meets the handwheel. I can get away with an 80mm pulley instead of 50mm, which will make it easier to find one with enough "web" to bore out its center to 20mm. The next thing I learned is that with a bit of machining on the round end of the retainer, I can increase my 11mm pulley width spec. all the way to 18mm if I want to. With those in mind I have found a good solution in this pulley from SDP-SI:

 Part Number: A 6A 3M30H9508

It is a dual flange, no hub, XL pitch model that already has the setscrews threaded through the teeth. I looked at their 3D model of it, and I am reasonably certain I could bore its 8mm center out to 20mm. And 8mm just happens to be the size of the output shaft on the motor I will use to drive the project. So I can order a pair of these and get things underway.

[efrench]

That's good news.  Are you sure you want to drive it 1:1? 

[MetalMuncher]

That's good news.  Are you sure you want to drive it 1:1?

I'm pretty satisfied with the speeds I get on the X axis, so I think 1:1 will be fine using the same drive unit on the Y axis. If I change my mind after using it I can switch out a pulley.

I've not decided yet how I want to tension the belt, or how long the belt will be. Once I get the pulleys and drive unit here on the bench I'll work all that out.

[rythmnbls]

...
I thought about trying to put a stepper motor on it with a CNC type controller, but I've never seen that done while also retaining the handwheel, and it would make the handwheel stick out quite a distance, presenting the risk of  catching on it while working on other projects near the mill. Utilizing another of the X-Axis style self-contained drive and control unit would save me a lot of research and design. I just need to add it to the Y axis leadscrew somehow.

Any suggestions are welcome.

Fignoggle sells CNC plans that keep the handwheel where it is.



Eric

I completed a conversion with those plans, here's a pic of the Y - Axis handwheel after the work was done.



The sleeve with the graduations is removed from the handwheel and a timing belt pully is bored out to fit over the journal that the sleeve previously occupied.   The downside is you loose the ability to measure distance with the handwheel.

Regards.

Steve.

[MetalMuncher]

Thanks!

Ha, this is PRECISELY what I have decided to do. The only issue I had left was trying to find the right sized timing pulley to bore out and put on the 20mm journal after removing that collar. But they went one step further, which I was concerned about taking.

When you remove the graduated ring collar, the handwheel casting still protrudes from the back of the handwheel. I have not measured just how much. The ring is only 11mm wide, so I was looking into milling away some of the screw retainer (seen on the right in your photo) for part of the pulley bore to extend over it. I didn't know if turning down the actual handwheel casting part to 20mm would leave it strong enough to still be used as a handwheel. But it seems Fignozzle thought so. Interesting! I may do this instead of my other plan, because it will provide much more support for the bore of the pulley than having that bore protrude partway out into thin air, revolving around the turned down retainer, as I had planned to do.

The only differences between how Fignozzle did it and how I will be doing it is that I'll be sending the belt to the right, due to my Y axis scale mount being close on the left side of the handwheel, and I am going to use one of the Powerfeed Controllers sold typically for the X axis feed on a SIEG X2, such as those from Little Machine Shop or Micro-Mark, to turn the belt. This gives me a plug and play speed controller, overload cutoff, and reversible motor all ready to go. The pulleys I ordered have 8mm bores, so one will fit on the controller output shaft without modification. The other I'll bore out to 20mm to mount as in your photo. I don't really have any interest in going CNC, so this, with my existing X axis power feed and DRO, will be enough for the one-off jobs I do here.

Fignozzle doesn't have nice photos like yours to illustrate how their plans go together, unless of course you buy the plans. Your photo is the "proof of concept" I needed to reassure myself this idea I had (even before I learned of Fignozzle)  is going to work.

Thanks again!

Now comes the hard part..................waiting for the ordered parts to arrive. 

[rythmnbls]

This is the pulley I used http://www.mcmaster.com/#6495k724/=ycqshc I also faced the main flange of the handwheel back a few mm to reduce the overhang of the pulley. Hope this helps.

Good luck with your build.

Regards,

Steve.

[MetalMuncher]

Thanks!

[MetalMuncher]

...
I thought about trying to put a stepper motor on it with a CNC type controller, but I've never seen that done while also retaining the handwheel, and it would make the handwheel stick out quite a distance, presenting the risk of  catching on it while working on other projects near the mill. Utilizing another of the X-Axis style self-contained drive and control unit would save me a lot of research and design. I just need to add it to the Y axis leadscrew somehow.

Any suggestions are welcome.

Fignoggle sells CNC plans that keep the handwheel where it is.



Eric

I completed a conversion with those plans, here's a pic of the Y - Axis handwheel after the work was done.



The sleeve with the graduations is removed from the handwheel and a timing belt pully is bored out to fit over the journal that the sleeve previously occupied.   The downside is you loose the ability to measure distance with the handwheel.

Regards.

Steve.

Hey I'm curious, if you don't mind my asking, how you mounted the handwheel to turn down the inner hub on it for the gear? I can think of 2 ways to mount it. Were you able to clamp the outer handwheel ring in your lathe vise, or did you mount the handwheel on a 10mm shaft as a mandrel, and put the shaft in the lathe vise?

[rythmnbls]

I mounted the hand wheel in the 4 jaw chuck by the outer rim.



Regards.

Steve

[MetalMuncher]

Thanks Rythmbls.

That method worked for me as well. I have the handwheel turned down now, and have started boring out the pulley that will go on it.

These pulleys surprised me in their design. I chose a "no-hub" pulley design to get the thinner sizes, but I am going to refer to the center as the hub, below, for lack of a better term.

As you can see in the photo, they are apparently assembled from at least 2 or more components. I am not sure if the crimps running around the flange/hub junction are just to hold flanges on, or if the notched perimeter is a piece they slide onto a blank center hub and swage it together. Either way, I was concerned about it breaking loose at that junction from the force applied while drilling the center out to 3/4" on my way to 20mm. So What I did was park the dual setscrews that came with the pulley such that they span the apparent junction, which would hopefully keep things from moving. Then I used a step drill in the lathe tail-stock (I love step drills!!) and it drilled out very smoothly, all the way up to 3/4". After I set up a boring bar to finish it off, I stopped for the night. When I get back to it I'll bore it to fit the handwheel journal.