Window crank extension available?

[Captain Obvious]

Nice work. Making parts like that sounds like it would be a simple matter, but they're really not easy. Especially to really make them right.

So are you cutting the splines with the part mounted in the lathe? Using the whole carriage in manual mode like a shaper? Little nibble at a time?  :) 

[Jeff Berk]

The splines are cut with an indexed fixture on a milling machine.   You select the correct index disk, mount the part in the chuck, cut the spline with an endmill. Then turn the hand crank and engage the pin selector to advance in this case 22.5 degrees to the next spline slot. Repeat until you have 16 cuts, then change the depth of cut and repeat.

Yes, its an absurdly, error-prone process. That's why I'm making a limited run and do not plan on selling them. 

Edited July 27, 2023 by Jeff Berk

[Jeff Berk]

Well after several tries, I came to conclusion that this may not be the best approach. The shaft extender extends the shaft too far for my application. Plan B is to replace the shaft entirely with one that is just slightly longer. That will have to wait until late fall when I put my Z in hibernation so I can pull the window regulator out for modification. 

I'll get back with the results of my experiment then.

[Captain Obvious]

Bummer. So going back to the beginning... Why won't the available aftermarket adapters fit? Number of splines wrong? What?

Did you ever purchase any of those aftermarket adapters?

[Jeff Berk]

My Captain,

I didn't purchase the aftermarket adapters because they were not the correct diameter and I wanted to try and make them myself. The aftermarket adapters were a two piece design with the sleeve and spline sections welded together. There was at least one complaint that the weld failed so I wanted to make it out of a single piece of metal. Billet seems to be a popular buzz word so why not.

It was easy but a little time consuming and most importantly, fun to make them so that's what I did. 

I noticed a comment from the aftermarket part manufacture that they could not make them any shorter and I understand the reason for that statement after I figured out how to make them. I only needed to extend the shaft a short distance to clear the padded leather covered door panel. Even after I modified the aftermarket design to shorten the length, the crank handle extended too far from the panel.

Creating an entirely new window regulator spline shaft should be as simple to make as these extensions however I don't have a picture and measurements of the other end of the shaft to design one and will have to wait for winter hibernation to make a few. I'll also likely have to switch to steel from aluminum.

[Captain Obvious]

 

On 9/2/2023 at 8:32 AM, Jeff Berk said:

Even after I modified the aftermarket design to shorten the length, the crank handle extended too far from the panel.

Yes, because of the very small extension amount you're looking to achieve, it's inherently impossible to do that with an extension. The problem is the splined portion of the extendo one and the splined portion of the original shaft must share the same space, and that is impossible. So you're looking at a different solution.

I'm not real keen on making a whole new shaft. I don't remember what is on the other end, but it might not be simple.

I think I would try to "extending the existing shaft."

Is there enough room to put in a short coupling collar? Or if not, a short piece of rod stock and weld the three parts back together.

Or cut the original splined portion off completely and then make a new splined piece (like what you've already made) and slip it over the (now blunt) stub of the original shaft? Wouldn't stick out as far because you've cut some length off.

Something like that.  

[Jeff Berk]

My Captain,

I saw a posting on cutting and rewelding the shaft to replace a damaged spline and I considered that and might end up going that route. I figure that a complete replacement should also be doable. I'll evaluate my options when I dig into the regulator in a few months. Thank you for the input.

[Captain Obvious]

I took a quick look at a window regulator yesterday and making a whole new part to replace the original shaft would be a large undertaking. Not only would you have to deal with the gear on the other end of the device, but the whole thing is riveted together originally and you would have to figure out a way to put it back together.

I think there is enough length there to cut off the original and put in an extendo collar. The other things to look into would be "Is there enough room in the system to allow for the increase in diameter an extendo collar would cause?"

In other words...  Is there enough room to increase that diameter or will it hit the door frame or door panel or something? If there is clearance, I would try an extendo tube device of some sort. Make it a precision fit onto the old shaft diameter and use setscrews to hold it in place?

[Jeff Berk]

I might just bite the bullet and pull a door panel off to take a look before winter.

[Jeff Berk]

Well, I had nothing better to do so I took it apart to see what's inside. I used to do that a lot when I was a kid. I figure I can reassemble it with some nuts and bolts or a spot welder I hope I still have access to.

It looks like the spline shaft is press-fit to an aluminum collar that mates to a spring. My options now look like the following (assuming I can put this back together):

1) Cut the shaft and extend it by adding a little steel by welding the two parts

2) Attach a short hollow tube between the two parts that can be welded or fixed with set screws. The added diameter would not be a problem.

3) Extract the shaft from the aluminum collar and turn a new shaft.

The easiest might be #2 and the most elegant would be #3. Separating the shaft from the collar would be my primary concern. 

Feel free to offer input. I'll try and get this to the makerspace in the next couple of days to see what's suggested.

[Patcon]

My concern would also be getting the shaft out of the aluminum. Going to be hard to use any force without breaking the aluminum. I think I would just cut the shaft and add metal in between the halves with the welder. That seems like the path of least resistance to me. Probably quickest too.

[Mark Maras]

I'd try a bit of heat on the aluminum first.