Need a little help on an Alexander D-bit grinder assembly... I'm stuck

[11andrew11]

Hi All,

I'm restoring an Alexander d-bit grinder that I bought on Craigslist. Before anyone asks, it came with 8 collets. I don't know the exact model name, but it's a bit different from most I've seen because the motor is mounted onto the main frame and turns the spindle directly.

I'm having trouble putting the lowest swivel joint back onto the main axle. I took many pictures and notes during disassembly and I don't recall anything odd about these peices, other that it took some effort to get the axle out.

On the lowest swivel piece, there is some kind of clamping mechanism that I don't quite understand. It is slightly proud of the inner surface of the hole for the axle, preventing the axle from sliding through. The interfering piece doesn't move and I got no hints when installing the clamping screw and lever handle. I feel like I must be missing something obvious and it's driving me crazy. In the picture, below, you can see it protruding at 12 o'clock in the hole. Has anyone run into this on a Alexander, Deckel, or other d-bit grinder that can shed some light on the issue?

 

[11andrew11]

Well, go figure. Minutes after writing this, I went at it again. I had dropped in a little ATF/Acetone combo and let it soak. Then I tapped it with a punch, and something seemed to move. One end of the protrusion was lower than the other, so I ran the axle in from that direction and it pushed the thing (I think it's part of a clamp) back enough for the axle to run all the way through. Problem solved.

 

[pontiac428]

It appears to me that the direct drive model furnishes a much slower wheel RPM. Might be nice for keeping things from getting too hot, but typical spindle speeds are approaching 5k RPM on other 4-1/4" grinders.

That fixing mechanism from Alexander is a big step up from the slit and clamp style on the Deckel clones. And the land levers are tucked into the castings, not proud and in the way. Enjoy tool grinding. It pays off big time in the long run.

 

[11andrew11]

Thanks for taking the time to share your thoughts. Very interesting observations. I'll look at the RPM on the motor plate and report back. I did get it all back together today and only need to run wires from the motor to a switch and plug. I'm pretty happy with the results. I used Krylon Midnight Garden, from Lowes, to (try to) match the original color. In the prior picture in my first post, only the collet holder was the original color, though I also found it on the bottom side of the machine.

 

[pontiac428]

Looks fantastic. The fit and finish of the Alexanders is superb. The elegant design of the castings offers a lot of clearance for movement versus the chunky offshore imports. You have a lot of room to move. I look forward to seeing your tool grinding progress.

 

[Larry$]

Were any of the parts worn much?
I've got a Chinese knock-off, Shars, that had some issues with clamping when I got it new. Now that it has been used some those issues are less. The problem is the slit casting clamping system & tolerances. Being able to move the spindle axially on the belt drive machines seems like a bit of an advantage. It took me a while to get decent results. But now I can sharpen the end of milling cutters very quickly. Grinding the flutes is another matter! Be sure to use dust collection when grinding carbide! Cobalt isn't good for you. Be safe, have fun.

 

[11andrew11]

Looks fantastic. The fit and finish of the Alexanders is superb. The elegant design of the castings offers a lot of clearance for movement versus the chunky offshore imports. You have a lot of room to move. I look forward to seeing your tool grinding progress.

I'm itching to try it out!

Regarding the fit and finish, I did find a little bondo underneath the paint where there were pocks in the casting. I replaced it after stripping everything down. I didn't do quite as nice a job as the factory, but I hit the visible areas.

I didn't yet mention it's a 3-ph 50hz motor but I'm not about to try to replace it w/ a 1-ph motor. Thankfully, I installed a Rotary Phase Converter in my garage years ago, so it's plug and play. It seems to run fine, and I think it must be running at 60/50ths of the RPM on the plate (I'll get that today!). I'm just waiting for a new 3-ph plug and a few fittings and it'll be ready for prime time. I'm going to mount an old Cutler Hammer Start/Stop switch to the back of the base, using an existing hole that is more often used to attached the motor. Then, the wire will drop down out of the motor to the 3-ph switch and then exit as a 3-ph extension cord.

I did something that may be unorthodox. I ran out of clear enamel paint and only had clear gloss polyurethane on the shelf. Being impatient, I tried it rather than waiting for more enamel to arrive in the mail. I'm quite pleased with the finish and it should be more durable.

 

[11andrew11]

Were any of the parts worn much?
I've got a Chinese knock-off, Shars, that had some issues with clamping when I got it new. Now that it has been used some those issues are less. The problem is the slit casting clamping system & tolerances. Being able to move the spindle axially on the belt drive machines seems like a bit of an advantage. It took me a while to get decent results. But now I can sharpen the end of milling cutters very quickly. Grinding the flutes is another matter! Be sure to use dust collection when grinding carbide! Cobalt isn't good for you. Be safe, have fun.

I don't think there was too much wear. Everything works as it should and all the clamping grips just fine. There is a gib on the dovetail ways for adjustment there. If you look closely, you'll notice that this grinder does not have left/right ways, only fore/aft, which leads me to think this was an earlier machine. I didn't quite follow your comment about moving the spindle axially being an advantage, probably because I've not yet used mine. Would you mind explaining that a bit more, please?

Thanks for the heads up on the dust collection. I do have a dust collector with a few extra ports and I think now is the time to give it more exercise. I also just acquired a Brown & Sharpe No 2 surface grinder, not that long ago, which needs a thorough cleaning (it works marvelously well!) and that will also require some dust collection.

Interestingly, I bought this from a small company that worked on MRI equipment, in Santa Clarita, just north of Los Angeles. The gentlemen had a German or maybe Dutch accent. He also had a Deckel S0 and was keeping that one. He mentioned that his uncle had bought this Alexander new, while still living in Europe, and brought it to the US when he immigrated.

 

[pontiac428]

Interesting that you have an American copy of a German machine that was made with EU power specs.

Don't worry about running the 50 Hz motor at 60 hz. I overdrive a number of 50 Hz tools and appliances at 120% and have been for years.

As you start using the machine, you will realize it has certain angles that require creative thinking to grind. The more over center travel you have on yaw, the more hat tricks you can pull when sharpening certain tools.

 

[11andrew11]

I finally made all the parts to run the wiring for my grinder and thought I would share a few more pictures.

I mounted an inline Cutler Hammer switch to the back of the grinder using an existing hole that would normally be used to attach the motor base plate to the main grinder unit. I used my lathe to turn the appropriate sized cylinder, threaded the end, and finally cut it using my mill so that would it mate with a slot that I cut into the switch box. The purpose is so that I can move the switch location left/right by about 1.5" if desired:

I also 3D printed an adapter so that I could mate the PG19 wire cable gland to the motor junction box;

And, finally, the finished project. Now it's time to clean up some endmills.