Graziano 12S

I think I would try a brake hone tool first, just held by hand, with the spindle running.. I worry that it could be easily over done.
 
ACHiPo said:
I'm wondering if I should get a MT5 test bar, as direct measurement of the 5MT taper seems pretty good? Seems like it would be good to have to dial things in anyway, in addition to making a test bar to dial in leveling?
Click to expand...

If you think about it, the inside of the spindle taper is all gnarly. Putting the taper of a test bar in there is not going to give you the precision you need. Test bars are somewhat useful for headstock alignment but you can do that by making test cuts on a bar held in the chuck so it really isn't going to be all that useful for you. For leveling the lathe you will be using a 2 collar test bar and for tailstock alignment you can make a very accurate test bar on your lathe so, in my humble opinion, I think a 5MT test bar is not a good use of your funds.
 
Superburban said:
I think I would try a brake hone tool first, just held by hand, with the spindle running.. I worry that it could be easily over done.
Click to expand...
I had to Google brake hone. Now that I know what it is, it looks promising! Thanks!
 
Evan, you have room for lots more stuff in there!
 
mikey said:
If you think about it, the inside of the spindle taper is all gnarly. Putting the taper of a test bar in there is not going to give you the precision you need. Test bars are somewhat useful for headstock alignment but you can do that by making test cuts on a bar held in the chuck so it really isn't going to be all that useful for you. For leveling the lathe you will be using a 2 collar test bar and for tailstock alignment you can make a very accurate test bar on your lathe so, in my humble opinion, I think a 5MT test bar is not a good use of your funds.
Click to expand...
Mike,
You may be right, but I was too quick on the Ebay draw. Should have one coming from India in a couple weeks. It cost about what I paid for my SO cord for the RPC connection, so not bad if it is as effective as I hope.

At a minimum I want to try Dykem transfer with a known-good taper to see how it mates, plus if I do hone/ream it will provide feedback for fit and runout. I also suspect it will measure well based on my indicator measureents, but I’m not sure.

Evan
 
ACHiPo said:
I slid the collet adapter into the spindle and gave it a thump with the heel of my hand. I was pretty happy with how firmly it "stuck" which I take as another positive indicator.
Click to expand...
yes very positive and this means more than the look of the taper or measurements you made.
What about making your own lapping tool to clean up the taper? You have to avoid brake cylinder style hones that are designed for cylinders. Honing/lapping a taper requires a special tool that you can make using the test bar you ordered.
 
Last edited:
I think lapping would be painfully slow on a hard spindle with a big 5MT taper. It would be like trying to polish a scratch out of your windshield with grease. I also don't like the idea of a lapping arbor, which should be of softer material than the work, deforming or wearing out of spec during the process and leaving you with a wavy surface entering the spindle taper.
 
I heard back from Spindle Grinding Service, Inc. They do not grind 5MT spindles. The recommended High Speed Technologies in Candia, NH, but I would need to remove the spindle, which I'm not interested in doing.
 
Quote from another forum: 'Lapping is a precision process where consumable, made-to-suit special tooling is required along with hours of careful work by a skilled hand. Hard maple makes an excellent lap but you'll need to make several as Cal states and be ready to adjust them according to progress.'

Lapping is probably not the right word for the procedure I am suggesting. But first I would use the new MT5 test bar with bearing blue to get a better reading on what the problem is. If the internal taper is already holding somewhat I would not want to give it an aggressive treatment.

The tool I visualize would contact the full length of the taper. Then add strips of self adhesive wet /dry SiCa paper in 2000 to 4000 grit. Give it a few light turns in the taper. Since there is probably very little to remove it would not take forever.
The idea is along the same lines as an MT5 cleaning tool but with a hardwood arbor and very fine sandpaper instead of felt strips.

KBC,KBC 50 TAPER SPINDLE WIPER,7-170-003,KBC Tools & Machinery

KBC,KBC 50 TAPER SPINDLE WIPER,7-170-003,KBC Tools & Machinery
www.kbctools.ca www.kbctools.ca
 
Last edited:
You must log in or register to reply here.
Back
Top