Turning down a small pin without a lathe

[precisionworks]

The lower thrust bearing collar got loose on the mill (the ring right above the R8 spindle taper). It has three holes, .196" diameter, and a pin spanner is used to tighten it in place. I had an Armstrong wrench, but the pins were .250" ... and the wrench arms are 9" long, meaning an 18" or larger lathe would be needed.

Since that isn't an option today, I mounted the boring head in the mill, inserted a boring bar backwards, and ran the machine in reverse. Adjusting the boring head backwards takes a little getting used to

Setting up on the part with the Indicol attached above the boring head:

Running the boring bar backwards (CCW):

Both pins turned down to .195":

Finished pin spanner holding collar:

Not bad, as long as everything is done in reverse

 

[StrikerDown]

Not bad, as long as everything is done in reverse

Smart thinking!

I was wondering the other day while putting the fenner belts on how running backwards would effect the directional belts.

I can't think of a lot of reasons to run it backwards though except a backwards boring bar or threading sans Tapmatic.


How did you notict it getting loose?

 

[wquiles]

Very clever idea

Will

 

[precisionworks]

How did you notict it getting loose?

It backed out all the way, and dropped down onto the collet chuck ... seemed like something that needed to be fixed pretty soon.

The boring bar & insert came from Mesa Tool - about $25 for the bar & $2.75 per insert - and it works well:twothumbs

http://shop.ebay.com/merchant/mesa-tool

 

[StrikerDown]

It backed out all the way, and dropped down onto the collet chuck... seemed like something that needed to be fixed pretty soon.

That would be kinda obvious

Now I know where to get a spanner if my collar goes for a walk... you deliver don't you?

 

[johnnymceldoo]

Sweet