Jr. Gent II TBC Bushings???
- Thread starter Scruffy
- Start date
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walshjp17
Member
I have JohnnyCNC's TBC bushings for the Junior series pens and they work really well.
Dan Masshardt
Member
Yup. They work well. I have sets from both places actually if you want a side by side.
brownsfn2
Member
I bought the ones from lazerlines because they were a pretty good price. They work great. Very solid and I don't need to tight up the tail stock as much without TBC bushings.
Of course if you are looking for .00x" accuracy then I would just get close with the bushings and turn final dimensions with the tube in between centers.
Of course if you are looking for .00x" accuracy then I would just get close with the bushings and turn final dimensions with the tube in between centers.
reddwil
Member
Been using them since he came out with them and I love them. No issues at all
edstreet
Member
Interesting to note they, lazerlinez, list them for mandrel and TBC. That will introduce some serious slop factor in if you use them on both. Also looks as their bushings has lack of real estate area in the TBC format.
the bottom middle shows the end of the bushing.
With that hole cut out for the mandrel that is some serious lack of real estate when doing TBC mode and lack of grip
the bottom middle shows the end of the bushing.
With that hole cut out for the mandrel that is some serious lack of real estate when doing TBC mode and lack of grip
I'm not sure exactly what you are referring to here.Interesting to note they, lazerlinez, list them for mandrel and TBC. That will introduce some serious slop factor in if you use them on both. Also looks as their bushings has lack of real estate area in the TBC format.
the bottom middle shows the end of the bushing.
With that hole cut out for the mandrel that is some serious lack of real estate when doing TBC mode and lack of grip
"Lack real estate"?? and what purpose would that real estate serve? Other than making the bushing slightly heavier, I can't think of anything.
I'm also not quite able to understand what you mean by "serious slop factor" and why you think using the bushings on both a mandrel and for TBC would have some adverse effect.
edstreet
Member
I'm not sure exactly what you are referring to here.Interesting to note they, lazerlinez, list them for mandrel and TBC. That will introduce some serious slop factor in if you use them on both. Also looks as their bushings has lack of real estate area in the TBC format.
the bottom middle shows the end of the bushing.
With that hole cut out for the mandrel that is some serious lack of real estate when doing TBC mode and lack of grip
"Lack real estate"?? and what purpose would that real estate serve? Other than making the bushing slightly heavier, I can't think of anything.
I'm also not quite able to understand what you mean by "serious slop factor" and why you think using the bushings on both a mandrel and for TBC would have some adverse effect.
Real estate being the contact area from the dead center in the lathe head to the mating surface on the bushing.
Slop factor. a.k.a. sloppy factor, fudge factor, margin of error. i.e. Excessive tolerance due to: out of round, non-round, non-square, etc. The reference that I made was using the bushing with a mandrel that had a bent rod, and wear taken on the bushing from sanding, chisel, etc. Then using it as a TBC bushing thus entering an oblong, oval or other non-round bushing.
Sorry, I should have been more clear in my original posting.
edstreet
Member
Not from the method that I mentioned. The only way I could see that being introduced is a some build up on the dead center or in the bushing gets in the way of metal on metal contact area. The smaller contact area would increase the chances of that happening. However we should all be keeping things as clean as we can so. Then again if you had 100% full coverage on the bushing that to would still be a viable problem that needs to be addressed promptly.
It is essentially like opening a jar with a cloth. The more contact area between the cloth and the jar lid yields more friction and strength you can apply. The question comes down to how much surface area is enough? That is something that I do not know the answer to. Perhaps someone out there does know and posts.
having closed bushings, i.e. Johnny CNC's for example you have very good surface area and there is no problem as it is near 100% coverage. The only down side to this is build up inside the bushing opening, this is not there in the center cut out as in the lazerlinez bushings. So it's a trade off, Strength or Build up? The key solution is in cleaning the bushings
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I understand now. I tend to think it isn't going to be a real problem for most users...time will tell.
Not from the method that I mentioned. The only way I could see that being introduced is a some build up on the dead center or in the bushing gets in the way of metal on metal contact area. The smaller contact area would increase the chances of that happening. However we should all be keeping things as clean as we can so. Then again if you had 100% full coverage on the bushing that to would still be a viable problem that needs to be addressed promptly.
It is essentially like opening a jar with a cloth. The more contact area between the cloth and the jar lid yields more friction and strength you can apply. The question comes down to how much surface area is enough? That is something that I do not know the answer to. Perhaps someone out there does know and posts.
having closed bushings, i.e. Johnny CNC's for example you have very good surface area and there is no problem as it is near 100% coverage. The only down side to this is build up inside the bushing opening, this is not there in the center cut out as in the lazerlinez bushings. So it's a trade off, Strength or Build up? The key solution is in cleaning the bushings