Thread: New Tapered / threaded mandrel for sanding and buffing razors

No offense taken.

I have received some questions about how long the arbor should stick out. Ans. No more than 9"!

The longer a rod is the easier it is to bend with a force applied to the end.
The outside circumference of a spinning wheel develops a outward pull which increases with the speed of rotation. Any slight imbalance is multiplied as that imbalance is spun faster.

This is a low speed arbor, only a half inch in diameter and designed to give max clearance for clean-up on a razor .
It should be run at less than 1000 RPMs = 4" pulley on the arbor and a 2+pulley on the motor.
Buffs and wheels limited to 4" Maximum!!!
Safety margin...some, but not a great deal!
This should keep people out of trouble! It is for very light duty and made for sanding and cleanup!

~Richard
PS, If someone wants to do the calculations, the formula is:
Centripetal force = mass x velocity2 / radius

First; there are more parts to be made and the shaft and arbor with pulley are just wedged into place for the trial with the odd piece of wood. All parts will be thoroughly located and fastened when finished..

Finally I had a a bit of time to do some machining and make a first fitting of the project:
I recently bought a cheap used 8 inch to center of spindle, drill press with five speeds at a garage sale.~$45


1. The key part of this buffer is the round aluminum block with a centered pocket on top and a centered spud on the bottom, the size of the slot in the bottom board, to locate the bottom board on center.
2. On top of it, centered to all, in that pocket, the end shaft bearing is mounted to hold the half inch rod from drill chuck carrying the drive pulley
3. Under that aluminum round, also centered is a half inch threaded rod sticking out the bottom...with a bushing around it made to exactly fit the hole in the drill press table.

I made a hand wheel from a surplus 5" caster, which I threaded, to lock all together when turned onto the threaded rod mentioned above.

Taken together it comes out like this:


Simple, What? WHY??

Simple, What? WHY??
The whole go'round is to allow the sliding of the bottom board and tightening and loosening the drive belt. The long board slot is to make the drill press column a centering and stabilizing device.
If I loosen the drive belt and turn the arbor end for end, I can reverse rotation.
If I reverse rotation that way, I retain the buffs or whatever on the ends of the shaft without spinning them off.
And..I do not need a reversing motor.
Oh Yeah..I get 5 speeds from the drill press!
And;I guess that it will also raise the arbor about eight to ten inches above the table top.
Cheers
~Richard
PS, it is always a good idea to have a bearing on the end of a drill press shaft when turning the shaft with a side loading, like routing with a routing cutter or this with the belt on the pulley making a side load..

Originally Posted by Geezer

If I loosen the drive belt and turn the arbor end for end, I can reverse rotation.
If I reverse rotation that way, I retain the buffs or whatever on the ends of the shaft without spinning them off.
And..I do not need a reversing motor.

I like the way you are thinking but this part looses me. If you have one end of the shaft threaded left hand and the other right hand you would have no reason that I can see to have to reverse direction.

What am I missing.

Tim

Why do I want to reverse rotation occasionally? That is an excellent question!
I will probably belabor the answer but here goes.

I may wish to apply the blade to either the tops or bottoms of the buffs or sanding drums to get the sanding effect and control I want. Think spine forward or edge forward with the blade in the best position to quickly see what I am doing or to best control the blade. By being able to reverse direction, I am then able to do that.

Consider; I like to clean and finish the majority of the blade with the sanding drum/grinding wheel rotating toward the spine. In some cases I may be able to see resulting grit patterns/sheen more easily using the bottom of a drum than hidden below the blade at the top of a drum which causes me to constantly flip the blade over to check progress and back to process it..

Think also, that I may have this or a similar piece of equipment, in the future,positioned to allow me to be able to have the shaft of the arbor pointing toward me while working. I then may look along a blade and align it more easily with the shaft and surface of the sanding drum.
That is how many razors and knives were originally ground between two wheels, the ends of which faced toward the operator.

I am basically tactile in nature and would be, as you can tell from my posts, barely able to talk without using my hands.

In the past, when i have designed products, industrial machines, fixtures, and jigs, it has been with the movements of the operator in mind to develop the kinematics necessary to reduce fatigue and accidents.

Because i have not used this particular evolution of a buffing machine, but have been using others for the past 50+ years, I am not sure how, exactly, it will be used but have made it possible to try many variations on a theme. I may use only one end or any other possibility available to accomplish the task I wish. I do not only refurbish razors but other items also. On some projects, I have used the end of the buffer shaft toward me. It can be a safety device also to prevent eating a difficult part. Rather than fly into me or bounce toward me, it flies past and does not damage anything but the hand that didn't hold it properly.

That is why only the arbor will be sold, there are as many possibilities as there are folks who want to do their own work. See Damon and Randy's configurations earlier.
Thanks for considerately asking your question!
Sincerely
~Richard

Originally Posted by Geezer

I am basically tactile in nature and would be, as you can tell from my posts, barely able to talk without using my hands.


~Richard

Good job,
even minus the visual of hands!

Thanks

Tim

The other guys are doing theirs also; expect some photo posts soon from them too. They have come up with differing ideas for their own spaces and usage. They stay in touch and ask questions that get me thinking!!

For my first trial:
Not much for looks; it does the job and is reversible when required. It made usable "cheap" prototype and I learned a lot. I got a few better ideas for the next one/s.

Have fun!
~Richard

Originally Posted by Geezer

. They stay in touch and ask questions that get me thinking!!


~Richard

Why not lay the drill press on its side and forget about twisting belts etc,?


Tim