TBC--slimline???

[Lenny]

Ed, you make a valid point. When i do use a madrel it is in my beal chuck, adjusted to as short a length as possible.
Still, there is nothing as satisfying as hearing that "pop" sound that Johnnycnc's bushings make when removed from a 7mm tube. Those who have tried it know what i mean. Some things just have to be experienced.

 

[Dale Allen]

Still, there is nothing as satisfying as hearing that "pop" sound that Johnnycnc's bushings make when removed from a 7mm tube. Those who have tried it know what i mean. Some things just have to be experienced.

Lenny, there are degrees to that as well. A bushing can be several thousandths too small and still 'pop' when you pull it out.
However, it may not be a tight enough fit to satisfy the eccentric!:laugh:

 

[Smitty37]

Ed, you make a valid point. When i do use a madrel it is in my beal chuck, adjusted to as short a length as possible.
Still, there is nothing as satisfying as hearing that "pop" sound that Johnnycnc's bushings make when removed from a 7mm tube. Those who have tried it know what i mean. Some things just have to be experienced.

The pop really has nothing to do with the guiding part of the bushing. That could could be square and you still get a pop when you pulled the shaft out of the brass tube..

 

[Smitty37]

Personally for 7mm Pen kits I don't think it will make a dimes worth of difference to a lot of us whether we use a mandrel or TBC but I do most 7mm with a mandrel because I like having both bbls together and most 7mm are two barrel.

 

[BayouPenturner]

I am still trying to visualize how to TBC without bushings. Won't that process have a tendency to flare out the ends of the blank/tube?

 

[BSea]

Ed, you make a valid point. When i do use a madrel it is in my beal chuck, adjusted to as short a length as possible.
Still, there is nothing as satisfying as hearing that "pop" sound that Johnnycnc's bushings make when removed from a 7mm tube. Those who have tried it know what i mean. Some things just have to be experienced.

That is so true.

I am still trying to visualize how to TBC without bushings. Won't that process have a tendency to flare out the ends of the blank/tube?

You just have to be careful not to put too much pressure on the blank. I normally don't buy bushings when I try a new kit. If I like it, then Ill buy the bushings.

 

[PenMan1]

I too have been experiencing OOR and I decided to take some measurements to come up with the best solution.

With a dead drive inserted in the headstock I get a deviation of .0015 if the dead drive is inserted to give me the best reading. If not oriented properly the dead drive deviation can be as much as .005.

The adjustable mandrel gives a deviation of less than .001, again if it is inserted with the right orientation. With the mandrel saver set at about a pen blank's distance that end of the mandrel whips around at about .008.

The Beall collet chuck gives a deviation of .005 at the chuck with a quarter inch drill bit inserted. I don't understand this because the Beall collet chuck "should" provide less deviation.

Larry, after reading this thru several times it appears that you have a situation similar to mine.
I won't go into great detail but basically it comes down to marking the dead center to get the least amount of runout, called the 'sweet spot'.
In my case I have determined that the MT2 was bored off center and the dead center I have also has a slight off-axis cut. If positioned correctly, the runout on the tip of the dead center is just under .002" so that is what I deal with. I have used a small file and marked the headstock drive and the dead center so it is easily positioned correctly each time.
If you have a problem with runout on anything that threads onto the headstock, and there is a runout on the headstock itself, there isn't much you can do about it since you cannot easily change the position of the chuck on the threads.

Larry:
I've NEVER, EVER seen a lathe that was completely accurate at the taper. USUALLY, the headstock is the most precise point on ANY lathe.

It DOESN'T HAVE TO BE the headstock/ Beall running OOR, but could be.

2 questions.
1. Is it a Beall chuck or a knock off? I've found that the bigger PSI and CSUSA chucks are NOWHERE NEAR as precise as the Beall.

2. Have you tried changing the collet in the chuck? MUCH LIKE the collet in an adjustable mandrel, ER32 chucks WILL SPRING, rendering OOR.
The is easy, just check the chuck with a different collet.

In "thumbnail" terms, attaching to your headstock should be AT LEAST twice as accurate as attaching to a taper.

 

[PenMan1]

If you ARE getting runout at the headstock screw, and not the collet chuck, have you checked to see that the pulley isn't loose or slipping AND IS in the correct place?

This could account for the off axis on both the MT and the headstock.

 

[PenMan1]

I am still trying to visualize how to TBC without bushings. Won't that process have a tendency to flare out the ends of the blank/tube?

If you are putting enough pressure to flair tubes, you need sharper tools.

 

[larryc]

Andy

Good points and I thank you for the responses.
I have had the Beall (yes it's the real thing) chuck for some time and have never used it but did set it up for this test. I only used one collet but your point is well taken about a collet problem.
I just went out to the shop and took a measurement on the headstock just behind and in front of the threads and there was zero runout in both places. When I installed the Beal chuck there was zero runout on the main body of the chuck where it screws on the headstock but on the collet holder snugged on to the chuck there was a .007 runout. Think JR will take it back after 5 years?:biggrin:

 

[Dale Allen]

Larry, if the inserts are not indexed, maybe you could try changing the position of the insert to see if the runout can be minimized. Start anywhere and mark both the insert and holder, then rotate it and recheck. Takes a while but it will tell you if the runout is the same all around or if possibly the holder is off too.

 

[PenMan1]

Andy

Good points and I thank you for the responses.
I have had the Beall (yes it's the real thing) chuck for some time and have never used it but did set it up for this test. I only used one collet but your point is well taken about a collet problem.
I just went out to the shop and took a measurement on the headstock just behind and in front of the threads and there was zero runout in both places. When I installed the Beal chuck there was zero runout on the main body of the chuck where it screws on the headstock but on the collet holder snugged on to the chuck there was a .007 runout. Think JR will take it back after 5 years?:biggrin:

Larry. If I'm reading your post correctly, this could be three things. Starting with the simplest, if this is the first time you've used the chuck, you do know that it is ABSOLUTELY IMPERATIVE that the collet BE loaded into the collar and NOT the chuck body, right? The ER32 has a definite "click" when properly inserted into the locking collar. It's impossible to get a collet chuck to run true by loading the ER32 into the body.

Secondly, JR LOADED the collet holders with Cosmoline before shipment. Wash the entire tool body AND the ER32 collet with K1 kerosene. Look for dried lubricant and scrape out any with a dental pick. Additionally look for dried "crap" in the splines of the ER32. All of the ER32 collets I've ever seen come fome China, and the quality is not much better than the collet in an adjustable mandrel.

Third, it COULD BE a bad locking collar on the Beall. I'm betting against this!

Good luck.

 

[edstreet]

I too have been experiencing OOR and I decided to take some measurements to come up with the best solution. With a dead drive inserted in the headstock I get a deviation of .0015 if the dead drive is inserted to give me the best reading. If not oriented properly the dead drive deviation can be as much as .005. The adjustable mandrel gives a deviation of less than .001, again if it is inserted with the right orientation. With the mandrel saver set at about a pen blank's distance that end of the mandrel whips around at about .008. The Beall collet chuck gives a deviation of .005 at the chuck with a quarter inch drill bit inserted. I don't understand this because the Beall collet chuck "should" provide less deviation.

Isn't it obvious where where it's at? The deviation that is.

Sent from my iPhone using Forum Runner

Enlighten me.

Lets us recap shall we?

• adjustable mandrel = less than .001
• mandrel saver = .008
• Beall collet chuck = .005
• dead drive poor oriented properly= .005
• dead drive oriented proper in the headstock = .0015

As we can see and as I discussed with Ed on the phone last week it all boils down to policy and procedures in how you use the equipment you are given.

Know your tools,
Know your material,
Know your self.

Poor usage of equipment yields bad results and poor precision. Equipment can not make up for poor usage or procedures when used.

 

[Smitty37]

The least reliable thing (and least accurate) in my arsonal is my vision - and no tool, regardless of how accurate can adjust for that. Even if the spin of the lathe is accurate to a gnats eyebrow I still won't be able to reach perfection in my turning.

 

[larryc]

Andy

Good points and I thank you for the responses.
I have had the Beall (yes it's the real thing) chuck for some time and have never used it but did set it up for this test. I only used one collet but your point is well taken about a collet problem.
I just went out to the shop and took a measurement on the headstock just behind and in front of the threads and there was zero runout in both places. When I installed the Beal chuck there was zero runout on the main body of the chuck where it screws on the headstock but on the collet holder snugged on to the chuck there was a .007 runout. Think JR will take it back after 5 years?:biggrin:

Larry. If I'm reading your post correctly, this could be three things. Starting with the simplest, if this is the first time you've used the chuck, you do know that it is ABSOLUTELY IMPERATIVE that the collet BE loaded into the collar and NOT the chuck body, right? The ER32 has a definite "click" when properly inserted into the locking collar. It's impossible to get a collet chuck to run true by loading the ER32 into the body.

This is the reason I have never used the collet chuck before. I could never (and still can't) get the collets to click into the collar.

Secondly, JR LOADED the collet holders with Cosmoline before shipment. Wash the entire tool body AND the ER32 collet with K1 kerosene. Look for dried lubricant and scrape out any with a dental pick. Additionally look for dried "crap" in the splines of the ER32. All of the ER32 collets I've ever seen come fome China, and the quality is not much better than the collet in an adjustable mandrel.

The collet holder and collets are all clean.

Third, it COULD BE a bad locking collar on the Beall. I'm betting against this!

That may be why I have never gotten the collets to "click" in and the runout on the outside of the collar.

Good luck.

Thanks

 

[larryc]

The least reliable thing (and least accurate) in my arsonal is my vision - and no tool, regardless of how accurate can adjust for that. Even if the spin of the lathe is accurate to a gnats eyebrow I still won't be able to reach perfection in my turning.

Smitty

I had cataract surgery on both eyes last month and what a difference it made. I'm not saying that's your problem but if your eye doctor recommends it go for it.

Larry

 

[PenMan1]

If the collects are not clicking into the collar, that is likely the problem. I'd call JR. IIRC, my Beall came with a lifetime warranty.

The Beall is too valuable not to be used.

 

[Smitty37]

The least reliable thing (and least accurate) in my arsonal is my vision - and no tool, regardless of how accurate can adjust for that. Even if the spin of the lathe is accurate to a gnats eyebrow I still won't be able to reach perfection in my turning.

Smitty

I had cataract surgery on both eyes last month and what a difference it made. I'm not saying that's your problem but if your eye doctor recommends it go for it.

Larry

Cataracts are not my vision problem that might be the only thing about it that I really understand.

 

[TBCbushings]

I use both but and TBC is a better option in MHO... Being a machinist I prefer TBC. I make my own bushings for TBC on kits I do the most. I make them as I need for kits.