F
frwillia
Guest
This a longer post than I originally intended, but for what starts out to be such a simple subject, it turns out here are a lot of significant details.
I've done a search all over the WEB and on here, and read everything I can find about reamer holders, downloaded it and pasted it in a document so I could study it where ever I am - doctors and dentist waiting rooms, on the throne, sitting on a bench in the mall waiting for my bride to finish shopping, <where ever>. None of it answers one question I have.
Some background:
When I did my first barrel, I used a small lathe dog, ran the spindle at 36 rpm, took gentle continuous cuts for a depth of .050" at first, and .025" after .050" caused chips to ooz out of the reamer flutes. The back end of the reamer was pushed by a flat surface in the tail stock.
It worked, and near as I can tell, I didn't get an over size chamber. The reamer had zero side play the last time I checked which was 0.020" from final depth. I don't have a DTI that can reach that far in. This is a budget operation with lots of home made tooling. I only buy what I can't make, which is DTI's, reamers, and barrels, but I still want to do this right if I can figure out what "right" is.
That said, the assymetrical force on the one sided handle keeps nagging at me. I went really slow to minimize it - I doubt it was over 5 lbs at any time, but I keep wondering if I should use some sort of symetrical torque reaction control handle.
Reamers cut sideways. The next two chambers will be cut with a new PTG reamer which will be pretty sharp.
I see all sorts of reamer pushers that seem to work well for their users that are one sided.
The Bald Eagle holder is one sided. It pushes with a hemispherical hardened rounded surface against a flat one (which I assume is also hardened). This appears to work well, lots of folks use them. It does have the property that this sort of pusher has no radial self correction, in fact it is the opposite. The farther off line it gets, the more it is pushed in the off line direction. This is a geometric fact but it may not be of significance. However, if one is using a one sided handle which might make the reamer want to cut sideways, and it gets off line, the reamer holder will tend to want to push it even farther.
I have the Richard Franklin video, he uses this. He slips what looks like a loose fitting aluminum handle over the holder handle and rests it on his fingers on the cross slide. When he stops he slips the extension off, lets the holder rotate, and pulls the reamer straight out after the spindle stops.
I didn't rest my hand on anything but I did use his technique at the end of the cut to obviate any chance of loose reamer rotation with a chip under a flute and galling ugly grooves in my new chamber. In his video Gordy emphasizes the galling tendancies of Stainless. I'm trying to pay attention.
There is the one that pushes on the faced surface of a Sinclair case turning handle that looks like it might be able to be used with out quite the side force the one sided one has after a bit of practice, but that introduces other issues like the operator exerting a side force of his own while holding it. Might be able to eliminate that with practice but I don't know a way to measure it and it's hard to minimize the unmeasurable.
There is the similar principle holder/pusher that uses a round collar with a set screw and a one sided handle.
As an aside, I like the tube pusher idea because it is to some extent gently self stabalizing. If the reamer tries, for whatever reason, to misalign itself from the axis, it will exert greater force on one side of the tube that will try to push it back as long as the side of the tube doing the pushing is on the opposite side of the spindle axis from the misalignment (if the misalignment gets big enough that this isn't true, the chamber was long since junk but I thought I should mention there are limits to this self correction tendancy). This could be a big feature very early in the cut, maybe not so much of a help later on, but the tendancy to self center could be a feature of this type of holder.
This is profoundly different in operating principle from the Bald Eagle holder, though apparentlly folks don't realize it because they say they are the same, and clearly, if one studies the geometry of what happens when one gets slightly misaligned, they aren't the same. The study of what happens with slight misalignment is key to evaluating reamer holders. If everything is aligned they are all the same and there is no difference between the most expensive one and a drill chuck. It's what happens when there is misalignment that makes the difference.
There is a version that uses a piece of aluminum slipped over a two screw clamp type tap wrench with an aluminum handle extension resting on the compound which I assume slides off to stop the process if there is a hitch of some sort, with the reamer pushed th the flat end of a tail stock drill chuck arbor.
Then there is the Manson holder that provides radial movement (slides sideways but keeps the reamer pointing in the same direction) but nothing angular - this, if works as advertised would have a symmetrical torque reaction with lateral compliance.
The Gre-Tan holder (I think this is what Gordy uses or is very similar to what he uses in his video) allows angular movement but apparently no radial compliance. This requires perfect alignment between the tail stock and the spindle axis. I can get that pretty close, but the tail stock spindle as it nears 2.5" of extension will have a few tenths of lateral movement so I can't guarentee it is always in line - then again that may not matter and provides the missing few tenths of radial complaince.
And of course there are the folks that have some sort of multiple kilobuck universally all compliant with zero slop holder made in a land far away they found at a garage sale, but i'm not planning on finding one of those anytime soon.
My real question is related to the assymetrical force on the reamer. Clearly most folks don't regard it as an issue because there are a lot of single sided reamer handles. But some apparently do because eliminating that side force is the biggest reason i can see to use the Gre-Tan or Manson type of holder (which appear to be profoundly different mechanisms to me - symmetrical torque reaction being about the only common factor).
I'm going to make myself a reamer pusher. My initial thought is to make one that has both features. I was going to make a brass shop built version of the Sinclair case turning handle (a short handled two screw square hole tap wrench handle in effect) pushed by a tube. the plan is to hold it by both handles to start the cut, then use a slip over one sided handle as the cut progresses.
Any thoughts on the significance of the single handle side force?
I wasn't planning on drilling and boring the chamber first. I frankly don't see how to make this work with out using either the Manson or Gre-tan holders, but I could be wrong about that. Can I pre-drill and bore and use something like the Bald Eagle or tube pusher and have it work?
Fitch
I've done a search all over the WEB and on here, and read everything I can find about reamer holders, downloaded it and pasted it in a document so I could study it where ever I am - doctors and dentist waiting rooms, on the throne, sitting on a bench in the mall waiting for my bride to finish shopping, <where ever>. None of it answers one question I have.
Some background:
When I did my first barrel, I used a small lathe dog, ran the spindle at 36 rpm, took gentle continuous cuts for a depth of .050" at first, and .025" after .050" caused chips to ooz out of the reamer flutes. The back end of the reamer was pushed by a flat surface in the tail stock.
It worked, and near as I can tell, I didn't get an over size chamber. The reamer had zero side play the last time I checked which was 0.020" from final depth. I don't have a DTI that can reach that far in. This is a budget operation with lots of home made tooling. I only buy what I can't make, which is DTI's, reamers, and barrels, but I still want to do this right if I can figure out what "right" is.
That said, the assymetrical force on the one sided handle keeps nagging at me. I went really slow to minimize it - I doubt it was over 5 lbs at any time, but I keep wondering if I should use some sort of symetrical torque reaction control handle.
Reamers cut sideways. The next two chambers will be cut with a new PTG reamer which will be pretty sharp.
I see all sorts of reamer pushers that seem to work well for their users that are one sided.
The Bald Eagle holder is one sided. It pushes with a hemispherical hardened rounded surface against a flat one (which I assume is also hardened). This appears to work well, lots of folks use them. It does have the property that this sort of pusher has no radial self correction, in fact it is the opposite. The farther off line it gets, the more it is pushed in the off line direction. This is a geometric fact but it may not be of significance. However, if one is using a one sided handle which might make the reamer want to cut sideways, and it gets off line, the reamer holder will tend to want to push it even farther.
I have the Richard Franklin video, he uses this. He slips what looks like a loose fitting aluminum handle over the holder handle and rests it on his fingers on the cross slide. When he stops he slips the extension off, lets the holder rotate, and pulls the reamer straight out after the spindle stops.
I didn't rest my hand on anything but I did use his technique at the end of the cut to obviate any chance of loose reamer rotation with a chip under a flute and galling ugly grooves in my new chamber. In his video Gordy emphasizes the galling tendancies of Stainless. I'm trying to pay attention.
There is the one that pushes on the faced surface of a Sinclair case turning handle that looks like it might be able to be used with out quite the side force the one sided one has after a bit of practice, but that introduces other issues like the operator exerting a side force of his own while holding it. Might be able to eliminate that with practice but I don't know a way to measure it and it's hard to minimize the unmeasurable.
There is the similar principle holder/pusher that uses a round collar with a set screw and a one sided handle.
As an aside, I like the tube pusher idea because it is to some extent gently self stabalizing. If the reamer tries, for whatever reason, to misalign itself from the axis, it will exert greater force on one side of the tube that will try to push it back as long as the side of the tube doing the pushing is on the opposite side of the spindle axis from the misalignment (if the misalignment gets big enough that this isn't true, the chamber was long since junk but I thought I should mention there are limits to this self correction tendancy). This could be a big feature very early in the cut, maybe not so much of a help later on, but the tendancy to self center could be a feature of this type of holder.
This is profoundly different in operating principle from the Bald Eagle holder, though apparentlly folks don't realize it because they say they are the same, and clearly, if one studies the geometry of what happens when one gets slightly misaligned, they aren't the same. The study of what happens with slight misalignment is key to evaluating reamer holders. If everything is aligned they are all the same and there is no difference between the most expensive one and a drill chuck. It's what happens when there is misalignment that makes the difference.
There is a version that uses a piece of aluminum slipped over a two screw clamp type tap wrench with an aluminum handle extension resting on the compound which I assume slides off to stop the process if there is a hitch of some sort, with the reamer pushed th the flat end of a tail stock drill chuck arbor.
Then there is the Manson holder that provides radial movement (slides sideways but keeps the reamer pointing in the same direction) but nothing angular - this, if works as advertised would have a symmetrical torque reaction with lateral compliance.
The Gre-Tan holder (I think this is what Gordy uses or is very similar to what he uses in his video) allows angular movement but apparently no radial compliance. This requires perfect alignment between the tail stock and the spindle axis. I can get that pretty close, but the tail stock spindle as it nears 2.5" of extension will have a few tenths of lateral movement so I can't guarentee it is always in line - then again that may not matter and provides the missing few tenths of radial complaince.
And of course there are the folks that have some sort of multiple kilobuck universally all compliant with zero slop holder made in a land far away they found at a garage sale, but i'm not planning on finding one of those anytime soon.
My real question is related to the assymetrical force on the reamer. Clearly most folks don't regard it as an issue because there are a lot of single sided reamer handles. But some apparently do because eliminating that side force is the biggest reason i can see to use the Gre-Tan or Manson type of holder (which appear to be profoundly different mechanisms to me - symmetrical torque reaction being about the only common factor).
I'm going to make myself a reamer pusher. My initial thought is to make one that has both features. I was going to make a brass shop built version of the Sinclair case turning handle (a short handled two screw square hole tap wrench handle in effect) pushed by a tube. the plan is to hold it by both handles to start the cut, then use a slip over one sided handle as the cut progresses.
Any thoughts on the significance of the single handle side force?
I wasn't planning on drilling and boring the chamber first. I frankly don't see how to make this work with out using either the Manson or Gre-tan holders, but I could be wrong about that. Can I pre-drill and bore and use something like the Bald Eagle or tube pusher and have it work?
Fitch
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