can someone advise me on a QCTP for ww lathe

S

sadbadger

im looking for a quick change tool holder for my 8mm ww lathe....yes like my previous posts,price is an issue...ill buy used but am unsure what to look for on e bay(like what type to look for) is a taig quick change good for watchmakers or sherline maybe?? or can these not be used on my lathe?)im also looking for a knurling tool...iv never heard of a ww type knurling tool,let alone anyone who uses a ww lathe for this purpose..id like to hear from anyone who has a knurling tool on their lathe and what kind i should buy for mine...thanks
 

Don Dahlberg

NAWCC Member
Aug 31, 2000
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Quick change tool holders for 8mm lathes are very hard to find. Most small set are still too large. Levin makes the best, but it is very expensive. See http://www.levinlathe.com/page15.htm
Perhaps you could find a used set.

Knurling puts a great deal of stress on a lathe. Perhaps you could do it on an 8 mm lathe, but it is not a very nice thing to do to such small bearings. If you would do knurling on such a lathe make sure you use the kind that has opposing knurls that push in opposite directions and will not stress the bearings as much. I have made a set of these for a larger lathe, but I guess you could scale them down. I used the plans at http://www.cartertools.com/knurl.html

Don
 
G

Gnomon

Knurling isn't in a WW lathe's repetoire.

First, knurling requires tremendous pressure. What you are doing is dimpling the work piece with the pattern embedded in the knurling wheel. Cone bearings will not withstand that kind of pressure. The typical pressure you apply to your cone bearings is a couple of grams at best. Knurling requires 50 to 100 pounds! Single point knurling is tough on even a big lathe.

Second, knurling is usually done at slow spindle speeds. The bearings on a typical knurl are just "plain" bearings. Hardened steel on hardened steel with a little oil. Knurling speeds are the same as single point threading speeds.... 50-70 rpm is a practical maximum.

Third, anything you would likely want to knurl would be big enough to twist with your fingers. That is after all the main reason for knurling. Something that large is already outside of the usual size range for a ww lathe.

-Chuck Harris
 
S

sadbadger

many or your points made sense but to say that anything large enough to twist with your fingers is outside the range of an 8mm lathe is a little far fetched..many people think that a watchmakers lathe is only for spinning extrememly small items...if this is so then why were there headstock riser blocks made available by many companies?? these risers make it possible to spin items over 4 inches..and as far as only putting two grams of pressure on the piece being worked..well good luck polishing an item with 2 grams of pressure let alone cut..if you are unwilling to put more than 2 grams of stress on your lathe well i dont think you can do anything with it..i really cant think of a single operation that can be done on a lathe that requires 2 grams.doesnt a penny weigh like 4 grams??anyway .i understand you wanted to make a point that knurling is not reccomended but you went a bit far..plus after doing some research iv spoken to many people who do light knurling with their ww lathe..but thanks for your input anyway
 
N

Niall

Take a look at eBay #4105754290

It looks as if it is not of the highest quality but it is not so very expensive either (70 Euro's).

I also have to agree with the other people: knurling is not a task for a WW lathe; you are better of buying a Taig, Unimat or Sherline for "general" machining. The WW lathe was not designed for it.

Niall
 
G

Gnomon

Hi sadbadger,

The poor little 8mm lathe is one of the jeweler's most abused tools. They were very expensive, so when a jeweler bought one he was by da*n going to use it for everything! The lathe manufacturers did their part to encourage that behavoir by making a wide variety of accessories that took the lathe to the limit of its capabilities and beyond.

If you need a grinder, or a buffer, buy one. They only cost $70 from Harbor Freight.

When I want to knurl, I use one of my "real" lathes. (12" Cincinnati, 10" Southbend)

-Chuck Harris
 

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