Good Floating Reamer Holder

CMaier said:
just to be clear..alex shoots well. and builds great rifles.
Click to expand...

I believe you
And I believe if you dial in both ends of the barrel
and prebore then ream without a pilot trying to influence the reamer to follow the bore instead of the dialed in points
you intend it to follow and end up at. You will get the results you want with only a pusher that will allow this.
I think I will just adapt his idea to my existing titanium pusher holder that I know is true by taking my handles off and turn a full radius handle to press on
Out of alluminum.
And leave the ball out because I already have that built in
to my pusher.
That will true itself to the holder that already has a true perpendicular face to the reamer
Does that make sense
 
Last edited by a moderator:
DSM said:
He is not pushing it with a dead center. Just pushing with a flat surface and the reamer simply follows the perfect bored hole. I run a similar set up with similar results and my tailstock sits high. When the needle on the DTI doesn't budge after reaming...something must be straight, lol.
Click to expand...

Thanks DSM,
I wonder if the people that posted have really looked at the setup or maybe they do not understand?
 
Butch Lambert said:
Thanks DSM,
I wonder if the people that posted have really looked at the setup or maybe they do not understand?
Click to expand...

What I see is a ground rod in the tail stock.
If it is not perfectly perpendicular to spindle axis as small as it may be
won't it still I influence the pusher out of parallel to spindle axis?
Like this O/ although this is much more extreme.
 
cloudrepair said:
What I see is a ground rod in the tail stock.
If it is not perfectly perpendicular to spindle axis as small as it may be
won't it still I influence the pusher out of parallel to spindle axis?
Like this O/ although this is much more extreme.
Click to expand...

Maybe if it's ground on a 45, lol. It's simply being pushed in a round bored hole that is true to the bore where it was dialed. The hole is what influences the reamer, in this case. There are reamer holders on the market that influence the reamer to the center of whatever is doing the pushing...which most likely isn't true to the bored hole.
 
Last edited:
DSM said:
Maybe if it's ground on a 45, lol. It's simply being pushed in a round bored hole that is true to the bore where it was dialed. The hole is what influences the reamer, in this case. There are reamer holders on the market that influence the reamer to the center of whatever is doing the pushing...which most likely isn't true to the bored hole.
Click to expand...

Yes the very small angle of slight tail stock misalignment is probably not enough on the radius of the ball to overcome the influence of the prebored hole.
 
DSM said:
He is not pushing it with a dead center. Just pushing with a flat surface and the reamer simply follows the perfect bored hole. I run a similar set up with similar results and my tailstock sits high. When the needle on the DTI doesn't budge after reaming...something must be straight, lol.
Click to expand...

All that means is the bore at the point the stylus is touching, is that the bore is round.
 
DSM said:
Yep..exactly
Click to expand...

I think there's way too much faith in this "perfectly bored hole" as that's highly unlikely that anyone can bore such a hole with a compound. If you used a roughing then a finishing reamer, maybe, but not with a boring bar hanging out that far on a compound. Compounds are like a tailstock. They are only in position at one point. When you move it, it wanders. With a tailstock the further you extend it the more it's skewed. a compound is no different, just not as bad, and it all is affected by every moving surface down to the lathe bed.
 
TRA said:
I think there's way too much faith in this "perfectly bored hole" as that's highly unlikely that anyone can bore such a hole with a compound. If you used a roughing then a finishing reamer, maybe, but not with a boring bar hanging out that far on a compound. Compounds are like a tailstock. They are only in position at one point. When you move it, it wanders. With a tailstock the further you extend it the more it's skewed. a compound is no different, just not as bad, and it all is affected by every moving surface down to the lathe bed.
Click to expand...
The key is whatever falt is in the compound the boring bar is still going to cut a true to the spindle axis hole as long as it doesn't push the part out of alignment.
That is why you check your work after every operation right.
Then you know and aren't guessing or assuming it's right. The words first article come to mind
 
Also your setup is going to have to be capable of the goal.
If the setup won't hold it right it won't mater if you have the best technic or equipment
 
Last edited by a moderator:
cloudrepair said:
The key is whatever falt is in the compound the boring bar is still going to cut a true to the spindle axis hole as long as it doesn't push the part out of alignment.
That is why you check your work after every operation right.
Then you know and aren't guessing or assuming it's right. The words first article come to mind
Click to expand...

I hate to disagree but a worn compound is not going to cut true to the spindle axis. Never gonna happen. All lathes have a sowbelly,or are twisted, and move around with the weather. Take the distance from the bed to the tool edge and just think how much .001 out of parallel at the bed would affect the tool edge. It's almost certain that the tool edge will rise of fall over the distance you would need to cut that taper. So much for your setup. Anytime something on a lathe moves it smiles at your set up. Cutting tapers with a CNC is not an exact science. Doing it while cranking on a wobbling compound is just not doable, with any so called perfection. If, IF, you bored a perfect hole with your compound, then you should be using that assembly to push the reamer. After all it's perfect to the spindle axis??? I don't think so. The one thing that is guaranteed is the tailstock is no where near true to the spindle axis throughout it's overall travel. Move it and it's going in a different direction.

With little short cartridges you can slide by, but when you are moving things 2.5-3"+ a lathe cannot perform miracles.

Those of you with access to CAD software, draw a circle and a flat round pusher. Give them an axis, enlarge them and then move the axis of the pusher around and also extend it at the same time. You will soon see that things are not as they seem.

Does any of this matter? That's up to you.
 
TRA said:
I hate to disagree but a worn compound is not going to cut true to the spindle axis. Never gonna happen. All lathes have a sowbelly,or are twisted, and move around with the weather. Take the distance from the bed to the tool edge and just think how much .001 out of parallel at the bed would affect the tool edge. It's almost certain that the tool edge will rise of fall over the distance you would need to cut that taper. So much for your setup. Anytime something on a lathe moves it smiles at your set up. Cutting tapers with a CNC is not an exact science. Doing it while cranking on a wobbling compound is just not doable, with any so called perfection. If, IF, you bored a perfect hole with your compound, then you should be using that assembly to push the reamer. After all it's perfect to the spindle axis??? I don't think so. The one thing that is guaranteed is the tailstock is no where near true to the spindle axis throughout it's overall travel. Move it and it's going in a different direction.

With little short cartridges you can slide by, but when you are moving things 2.5-3"+ a lathe cannot perform miracles.

Those of you with access to CAD software, draw a circle and a flat round pusher. Give them an axis, enlarge them and then move the axis of the pusher around and also extend it at the same time. You will soon see that things are not as they seem.

Does any of this matter? That's up to you.
Click to expand...

The boring bar doesn't need to cut a perfect hole it will still be true to the spindle axis even if it is leaving ugly finish that is different diameters through the bore. Even with the ways worn it will still be true to the axis if your part doesn't move on you
then you can let the reamer do its job shaping the chamber
now if your chamber measures same as reamer and part doesn't move you have dialed in right you will get the best results. The pusher also has to allow the reamer to follow your true hole.
 
Last edited by a moderator:
that certainly looks like a chuck in a tail stock with an indicator added on top.
and i clearly said if all is straight, it will work, BUT ONLY WHEN PERFECTLY STRAIGHT.


DSM said:
He is not pushing it with a dead center. Just pushing with a flat surface and the reamer simply follows the perfect bored hole. I run a similar set up with similar results and my tailstock sits high. When the needle on the DTI doesn't budge after reaming...something must be straight, lol.
Click to expand...
 
zfastmalibu said:
Heres my holder. The idea behind it is, its round so it cant grab your hand. Also being round makes it easier to hold the reamer without influencing it. Theres a ball bearing pressed in the holder and its pushed by a ground piece of carbide. I measure every chamber, they measure what the reamer does and I have never had a run out or chatter issue. I am pleased with it.
Click to expand...

That looks like my third generation pusher :)

Now, lose the ball and carbide arrangement, push it with the chuck or with a ring at least 1" diameter that sweeps perpendicular to the bore and ya' GOT Sumpin!

LOL


al
 
cloudrepair said:
The boring bar doesn't need to cut a perfect hole it will still be true to the spindle axis even if it is leaving ugly finish that is different diameters through the bore. Even with the ways worn it will still be true to the axis if your part doesn't move on you
then you can let the reamer do its job shaping the chamber
now if your chamber measures same as reamer and part doesn't move you have dialed in right you will get the best results. The pusher also has to allow the reamer to follow your true hole.
Click to expand...

Yep. No one is claiming their bored hole is perfectly on size over it's length, but it will be round and coaxial with the spindle.
 
Rubicon Prec. said:
Yep. No one is claiming their bored hole is perfectly on size over it's length, but it will be round and coaxial with the spindle.
Click to expand...

Isn't that exactly what TRA is saying ? Maybe not perfectly size but if you reread his post you'll see the reason for mine I didn't intentionally imply he was saying the hole would be perfectly sized just tru to the spindle axis was in quistion
Sorry misinterpreted your response disregard ^^^
 
Last edited by a moderator:
cloudrepair said:
Isn't that exactly what TRA is saying ? Maybe not perfectly size but if you reread his post you'll see the reason for mine I didn't intentionally imply he was saying the hole would be perfectly sized just tru to the spindle axis was in quistion
Sorry misinterpreted your response disregard ^^^
Click to expand...

He was saying it would not cut true to the spindle axis. I say it will even with a worn lathe, within reason, obviously. It may not be on size or shape but it will be concentric. But it doesn't matter because the reamer gives the final shape and size. If it has a concentric hole to follow and is allowed to do so, it will give a concentric and on size chamber.
 
Rubicon Prec. said:
He was saying it would not cut true to the spindle axis. I say it will even with a worn lathe, within reason, obviously. It may not be on size or shape but it will be concentric. But it doesn't matter because the reamer gives the final shape and size. If it has a concentric hole to follow and is allowed to do so, it will give a concentric and on size chamber.
Click to expand...

Yes agreed.

Machining and my family is what I live for not exactly that order
I'm not above learning from anyone I just want to do the best I can
And I don't always see what I should because I'm blind in one eye and can't see out of the other
 
You must log in or register to reply here.
Back
Top