# So, To Be or NOT to Be a Chaser!



## USMCDOC (Jul 6, 2017)

Ok, 

There is the very possibility that i will be doing a lot of 1/2-13 threading..and possible that i may do a 3/4-10 or a  7/8-9.  since change gears are such a pain in the buttooski, i have been wondering if it would be more prudent to invest in a good used Geometric or Rubometric Die Head or to go with a die holder.. There are two die heads that i have been looking at.. either a actual Geometric or Rubometric die head that can hold the dies for 1/2-13 thread, since this will be done on a 3" shaft. And the other can be done with the lathe, since i have to do both inside and outside threading of the larger thread.. it also will be of a short length.. what say you?


----------



## Bob Korves (Jul 6, 2017)

Depends on what the threads are for.  What kind of accuracy and thread fit is necessary for the job?


----------



## tertiaryjim (Jul 6, 2017)

Hand threading 1/2"-13 is hard enough. 3/4" takes a great deal of force.
I find its easyer to cut large threads on the lathe than to use a die and about as quick.


----------



## bfd (Jul 7, 2017)

you can single point the threads and finish for size with a die or die head. gets the threads square and on size quickly bill


----------



## USMCDOC (Jul 7, 2017)

tertiaryjim said:


> Hand threading 1/2"-13 is hard enough. 3/4" takes a great deal of force.
> I find its easyer to cut large threads on the lathe than to use a die and about as quick.



Yeah.. tell me about it! 



bfd said:


> you can single point the threads and finish for size with a die or die head. gets the threads square and on size quickly bill



i know that i can.. it is all the time wasted trying to change the gears.. it gets old.. but it may be the route that i end up going.. due to only that i am afraid that the lathe doesn't have the low end grunt that is really need to use a die head.. though i would


----------



## kd4gij (Jul 7, 2017)

Change gears shouldn't be an ordeal. What lath= do you have 

Sent from my SM-G530T using Tapatalk


----------



## T Bredehoft (Jul 7, 2017)

I have banjos made up for (right now) three different feeds, two threads and one turning feed, .0028. Changing banjos is quicker than changing sets of gears.  Make new banjos, buy extra gears. I have two more banjos to set up when needed. Made them from 1/8 CR steel.


----------



## benmychree (Jul 7, 2017)

If you have much threading to do, a die head is the way to do it; 1/2-13 can be done in one pass, accurately and with good finish; larger coarse threads may require a die head with a rough/finish capability, depending on what the material is, but 3/4NC should be no problem in one pass.  The Geometric/ Rubometric die heads are definitely the easiest to set up (change chasers) and use and chasers are available from a variety of sources, including E Bay.
Die heads may be set for size by making a series of plug gages matching the published minor diameter of the thread of whatever fit is desired; this can save a lot of time in adjusting the chasers to get the fit desired.   I have one 9/16" and one 3/4" style D Geometric die (the most popular type) and a 7/8" capacity Hartness die head; this is also a good die head, but more time consuming to set up and due to the fact that the chasers are recessed into the face of the head, it is more difficult to thread up to a shoulder due to not being able to easily see the chasers.  I also have a pair of J&L die heads with all the chasers and set up gages and sharpening fixtures; on this make of die head, the chasers are of the tangent type, sharpened on their ends, making for a very long chaser life, but take more time to set up, especially if the chaser holders have to be changed, but offer very tight tolerences,  These dies I have not used, I got them with a turret lathe that I bought for some of the tooling and accessories and resold what I did not want.


----------



## USMCDOC (Jul 7, 2017)

i have thought about this, back when i first got this lathe and i think that it is still a good idea to make at least a new one sometime in the near future.. but i was thinking so only due the aesthetics of the current one that is on there.. but yes.. changing out the loaded banjo on the PM1022V would be better bet if for single pointing.. 


T Bredehoft said:


> I have banjos made up for (right now) three different feeds, two threads and one turning feed, .0028. Changing banjos is quicker than changing sets of gears.  Make new banjos, buy extra gears. I have two more banjos to set up when needed. Made them from 1/8 CR steel.


----------



## USMCDOC (Jul 7, 2017)

i am looking at the Rubometric 3/4 right now.. and hold it with a ER40 collet holder. 



benmychree said:


> If you have much threading to do, a die head is the way to do it; 1/2-13 can be done in one pass, accurately and with good finish; larger coarse threads may require a die head with a rough/finish capability, depending on what the material is, but 3/4NC should be no problem in one pass.  The Geometric/ Rubometric die heads are definitely the easiest to set up (change chasers) and use and chasers are available from a variety of sources, including E Bay.
> Die heads may be set for size by making a series of plug gages matching the published minor diameter of the thread of whatever fit is desired; this can save a lot of time in adjusting the chasers to get the fit desired.   I have one 9/16" and one 3/4" style D Geometric die (the most popular type) and a 7/8" capacity Hartness die head; this is also a good die head, but more time consuming to set up and due to the fact that the chasers are recessed into the face of the head, it is more difficult to thread up to a shoulder due to not being able to easily see the chasers.  I also have a pair of J&L die heads with all the chasers and set up gages and sharpening fixtures; on this make of die head, the chasers are of the tangent type, sharpened on their ends, making for a very long chaser life, but take more time to set up, especially if the chaser holders have to be changed, but offer very tight tolerences,  These dies I have not used, I got them with a turret lathe that I bought for some of the tooling and accessories and resold what I did not want.


----------



## USMCDOC (Jul 7, 2017)

If i do go the route of single pointing instead of a die head.. i think that i will do it all with  a 13 pitch.. i have to do it for sure on the on the 1/2 shaft.. that is a given.. but i feel that i may do a double lead 13 pitch on the larger part.. speed in the movement is important there.


----------



## Silverbullet (Jul 7, 2017)

Most of the die heads are adjustable for thread fit. Buy the extended dies to get to a shoulder. If you have a lot to do that's the way. I have a big head and a medium 3/4"  + 2" die heads , I'm looking for a smaller one 5/16  or  up to 1/2"  I think my medium one will do 1/2 + 3/4" . Been awhile YUPP.


----------



## USMCDOC (Jul 7, 2017)

You are making me think that this might me something to do..


----------



## Wreck™Wreck (Jul 7, 2017)

This is excellent turret lathe work, do you have one? Using an opening die head in an engine lathe is not the most efficient way to go, if a recurring job that you can make a profit on year after year then invest in the die head.


----------



## USMCDOC (Jul 8, 2017)

Well, in another thread, i had mentioned about how the retainers for the gears to the banjo, that one had broken, well, they are sending some extras.. once they are here, i won't be so nervous about making gear changes..


----------



## jdedmon91 (Jul 27, 2018)

T Bredehoft said:


> I have banjos made up for (right now) three different feeds, two threads and one turning feed, .0028. Changing banjos is quicker than changing sets of gears. Make new banjos, buy extra gears. I have two more banjos to set up when needed. Made them from 1/8 CR steel.



Great idea for lathes without a QC box


Sent from my iPhone using Tapatalk


----------



## MrWhoopee (Jul 28, 2018)

Die head.


----------



## MarkM (Aug 8, 2018)

I don t think you can beat a geometric die head.  You can adjust for the class of thread your after.  In a different league on how much quicker it will be. If you have a surface grinder you can maintain the chasers, so a long term investment.  As stated would be great for a turret lathe!


----------

