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View Full Version : Should I Worry About These Weights Flying Out ????



JoeLee
03-20-2017, 10:25 AM
I'm at the point here with my balancing hub project to start making the weights. I have a piece of 932 bronze that I will make the weights out of as shown in the picture below.

http://www.wmsopko.com/images/00428.jpg

So my question here is ..... should I have any concerns of a weight coming loose and flying out of the groove???

I have been thinking about different ways to keep them locked in the groove in the event one should come loose.
I have thought of making the weight with a slight ridge or lip on both the inner and outer radius at the front of the weight where the slit opening is and turning a thin groove in the walls of the hub slot so the weight would have to be squeezed slightly to snap into place. This way in the event they or one should come loose it can't come flying out.
My other thought is to make a flat ring or plate that screws down to the face of the hub and extends a 1/16" or so over the weight groove thus preventing the weight from coming out. This is probably my easiest option, however the hub wall is .125 in thickness and I would have to use like a #4 screw to secure the plate to the hub.

I've only seen one balancing hub that had weights with a beveled edge that locked them into a groove but that was a two piece hub as with a design like that there would be no other way to get the weight in or out. Apparently it's not a safety issue.

Below are my finished hubs.

JL....................

http://i911.photobucket.com/albums/ac317/JoeLee09/Balancing%20Grinding%20Wheels/Image052_zps56bzcavi.jpg (http://s911.photobucket.com/user/JoeLee09/media/Balancing%20Grinding%20Wheels/Image052_zps56bzcavi.jpg.html)

A.K. Boomer
03-20-2017, 10:39 AM
JL cool design, what type of RPM's we talking? --- what's it going to be used for? is it in "harms way" should something come uncorked?

You might also get by with just totally balancing to perfection, scribe and then loc-tite both the expansion screws and the inner and outer holding flanges of the weights themselves although be sure that's where you want it and immediately test after for proper balance cuz depending on what type of loc-tite you use it could be a bugger to budge again even without the screws...

last but not least, how did you make that nifty drive washer???

cool project...

Toolguy
03-20-2017, 10:47 AM
That is the normal way to do balancing weights on a surface grinder. I have never had any come loose in many years. Just make sure when you tighten them to be firm, but not go crazy. The screws don't have to be all that tight to work fine.

A.K. Boomer
03-20-2017, 10:53 AM
another possible idea in case the hub is going to be used for intermittent adjustments for some reason or another,

when building the brass pieces im assuming you will be cutting them all from the same cloth so to speak as in making a ring and then dissecting it into three separate pieces --- before cutting get some 180 grit and drag on the inner and outer diameters,

do the same to your aluminum engagement hubs, now you have the equivalent of many crude slot engagements - all that would be needed is to loc-tite the expansion screws,

this would still allow for movable adjustments

possibly a place where mirror smooth "good" machining is NOT wanted...

JoeLee
03-20-2017, 01:31 PM
Were talking surface grinder spindle speed of about 3400 or 3600 R's for the larger hub. The smaller one for the T&C grinder may see spindle speeds of 5000 R's depending on wheel dia.
Since the weights have to be adjustable I can't loc-tite them in place or any thing like that.
Yes, I will make a ring and then cut the segments out, drill and tap for the 1/16" tapered pipe thread. I need to make two different size rings, one for each hub. I'll also have enough of the ring left to make extra weights when I decide to make a couple more hubs.
I had planned on scratching up the OD's and ID's for the reason you mentioned.

By the way.........the hubs are steel, not alum. One is for the surface grinder and the smaller is for the T&C grinder.
I have to make the PVC transfer bushings for each. This design is my own and is a little different than the typical hub that you would normally mount to the wheel and leave it mounted until the wheel is no longer usable.
I'll post more detailed pics of the transfer and mounting bushings when I finish the project.


JL..................

http://i911.photobucket.com/albums/ac317/JoeLee09/Balancing%20Grinding%20Wheels/Image017_zps2tgk1ofr.jpg (http://s911.photobucket.com/user/JoeLee09/media/Balancing%20Grinding%20Wheels/Image017_zps2tgk1ofr.jpg.html)

Mark Rand
03-20-2017, 03:57 PM
All of my hubs for my J&S surface grinder have dovetailed tracks for the balance weights.

It isn't noticably more complicated to make them that way than parallel slots.

boslab
03-20-2017, 04:41 PM
Thread lock
Mark

JoeLee
03-20-2017, 05:09 PM
Thread lock
Mark Nope.......

JL..............

JoeLee
03-20-2017, 05:11 PM
All of my hubs for my J&S surface grinder have dovetailed tracks for the balance weights.

It isn't noticably more complicated to make them that way than parallel slots. If the weights are dove tailed then I'm guessing you have to have a two piece hub.
I would like to see some pics of that.

JL................

Mark Rand
03-20-2017, 07:50 PM
No, the weights are in two separate halves with the screw between them. The weights can be fitted on the inside and outside of the track and then slid together. I think I've got a picture somewhere...

Found it:-

http://www.test-net.com/weight.jpg

http://www.test-net.com/wheel.jpg

JoeLee
03-20-2017, 10:05 PM
This is the first time I've ever seen of a split weight.

Thanks..... JL.................

A.K. Boomer
03-20-2017, 10:15 PM
Ok now were getting fancy, but - how bout a few degree's marked on each weight and an alignment notch on the hub with 2 others 120 degree's apart,,, you dial in your weights to balance, then "mirror image" them same positions and just rotate/flip the entire unit over and hold the weights against the wheel...

one extra step to adjust then set, no worried of them coming uncorked in yo faze -------------?

JoeLee
03-21-2017, 08:27 AM
I see what your getting at, and it is a good idea, but.......there is no way I can mount the hub backwards. With the added thickness I'm lucky I can get enough threads on the spanner nut to hold everything on the spindle.

JL...................

JoeLee
03-21-2017, 05:02 PM
This was a second thought for some added security to keep the weight from flying out.
A steel ball would be forced into the radial groove in the hub wall by a tapered set screw.

There are draw backs to this design as well.

JL.....................

http://i911.photobucket.com/albums/ac317/JoeLee09/Balancing%20Grinding%20Wheels/Image056_zpsd5eulxjf.jpg (http://s911.photobucket.com/user/JoeLee09/media/Balancing%20Grinding%20Wheels/Image056_zpsd5eulxjf.jpg.html)