cloudrepair
DWG
Yes that is just how I am always trying to complicate things when they can be solved with a simple answer.
Not usually a good thing but I've learned to deal with it somewhat
Good Floating Reamer Holder
- Thread starter Curious
- Start date
Yes that is just how I am always trying to complicate things when they can be solved with a simple answer.
Not usually a good thing but I've learned to deal with it somewhat
Dick Grosbier
Club Coordinator
As Mark twain would say. Rumors of Bill Gebhards demise are greatly exaggerated, I talk to him regularly.
zfastmalibu
New member
Havent been by in a while sorry for the delay. There is a ball bearing pressed into a 4" aluminum disk. Thats the holder, thats all. Its intentionally kept light so it has less effect on the reamer. It is pushed by a ground flat carbide. It can float without influence, there is no center involded. Offset tailstock has no effect unless it was not parallel to the spindle. Even in that case the effect it could have would be minute. The last .025" is cut holding the holder with only my thumb and index finger. I do have the capability to measure my chambers accurately, this arrangement easily produces reamer sized holes consistently for me. I chamber at 250 rpm with cutting oil run through the bore. I dont prebore. I have some core drills for big chambers, and smaller ones the reamers cuts the whole thing. On big ones that I dont have a core drill I will ream a 1/4" then drill 1" then ream to that and drill another 1" and finish ream. No need to bore. I do get the first 3" off bore running concentric to the spindle and that is what allows this. If I indicated the muzzle and throat I would bore. .0002" at the back end of a chamber is my normal reading for runout. The bottom line for me is, check your work, if your method is producing consistent results then it is fine. I do pride myself on cutting chambers that measure to the print. It has caused me plenty of grief with dies not sizing the base enough. One of the best shooting barrels I know of, that holds current 1000yd IBS records, has a very fat chamber, threads that are probably .010" small on pitch diameter and .040" small on major diameter. Most of what we do is for our own pride. 
Cloud repair, the holder you made is flat on the back and looks a little heavy. Whats the idea behind the flat? You say your going to push it with the same pusher, you mean a flat pusher? If so you have increased the surface area greatly and I see that holder having a hard time floating without influence. The ball bearing and carbide offers a small contact point with hard surfaces to minimize friction. I went back and saw your pusher. I still think the big flats will cause and issue, but the mic will let you know.
Cloud repair, the holder you made is flat on the back and looks a little heavy. Whats the idea behind the flat? You say your going to push it with the same pusher, you mean a flat pusher? If so you have increased the surface area greatly and I see that holder having a hard time floating without influence. The ball bearing and carbide offers a small contact point with hard surfaces to minimize friction. I went back and saw your pusher. I still think the big flats will cause and issue, but the mic will let you know.
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Havent been by in a while sorry for the delay. There is a ball bearing pressed into a 4" aluminum disk. Thats the holder, thats all. Its intentionally kept light so it has less effect on the reamer. It is pushed by a ground flat carbide. It can float without influence, there is no center involded. Offset tailstock has no effect unless it was not parallel to the spindle. Even in that case the effect it could have would be minute. The last .025" is cut holding the holder with only my thumb and index finger. I do have the capability to measure my chambers accurately, this arrangement easily produces reamer sized holes consistently for me. I chamber at 250 rpm with cutting oil run through the bore. I dont prebore. I have some core drills for big chambers, and smaller ones the reamers cuts the whole thing. On big ones that I dont have a core drill I will ream a 1/4" then drill 1" then ream to that and drill another 1" and finish ream. No need to bore. I do get the first 3" off bore running concentric to the spindle and that is what allows this. If I indicated the muzzle and throat I would bore. .0002" at the back end of a chamber is my normal reading for runout. The bottom line for me is, check your work, if your method is producing consistent results then it is fine. I do pride myself on cutting chambers that measure to the print. It has caused me plenty of grief with dies not sizing the base enough. One of the best shooting barrels I know of, that holds current 1000yd IBS records, has a very fat chamber, threads that are probably .010" small on pitch diameter and .040" small on major diameter. Most of what we do is for our own pride.
Cloud repair, the holder you made is flat on the back and looks a little heavy. Whats the idea behind the flat? You say your going to push it with the same pusher, you mean a flat pusher? If so you have increased the surface area greatly and I see that holder having a hard time floating without influence. The ball bearing and carbide offers a small contact point with hard surfaces to minimize friction. I went back and saw your pusher. I still think the big flats will cause and issue, but the mic will let you know.
Alex
Does the ball bearing contact the reamer ??
Matt P
cloudrepair
DWG
Havent been by in a while sorry for the delay. There is a ball bearing pressed into a 4" aluminum disk. Thats the holder, thats all. Its intentionally kept light so it has less effect on the reamer. It is pushed by a ground flat carbide. It can float without influence, there is no center involded. Offset tailstock has no effect unless it was not parallel to the spindle. Even in that case the effect it could have would be minute. The last .025" is cut holding the holder with only my thumb and index finger. I do have the capability to measure my chambers accurately, this arrangement easily produces reamer sized holes consistently for me. I chamber at 250 rpm with cutting oil run through the bore. I dont prebore. I have some core drills for big chambers, and smaller ones the reamers cuts the whole thing. On big ones that I dont have a core drill I will ream a 1/4" then drill 1" then ream to that and drill another 1" and finish ream. No need to bore. I do get the first 3" off bore running concentric to the spindle and that is what allows this. If I indicated the muzzle and throat I would bore. .0002" at the back end of a chamber is my normal reading for runout. The bottom line for me is, check your work, if your method is producing consistent results then it is fine. I do pride myself on cutting chambers that measure to the print. It has caused me plenty of grief with dies not sizing the base enough. One of the best shooting barrels I know of, that holds current 1000yd IBS records, has a very fat chamber, threads that are probably .010" small on pitch diameter and .040" small on major diameter. Most of what we do is for our own pride.
Cloud repair, the holder you made is flat on the back and looks a little heavy. Whats the idea behind the flat? You say your going to push it with the same pusher, you mean a flat pusher? If so you have increased the surface area greatly and I see that holder having a hard time floating without influence. The ball bearing and carbide offers a small contact point with hard surfaces to minimize friction. I went back and saw your pusher. I still think the big flats will cause and issue, but the mic will let you know.
It used to have a bronze raduis insert but I made a new pusher out of a piece of a tirod end if you look at the last pics I uploaded you will see the ball in it and tbe pusher is made of titanium and aluminum.
I had already made the titanium part so I know it is true perpendicular to the reamer bore so I just drew up the aluminum part on mastercam and had it jetted out then bored faced and heat/cold pressed it on.so j would still be going off the titanium part. Do you think I need to change it up.
press a ball into the titanium part and go back to a flat pusher?
zfastmalibu
New member
Try it out and measure your chambers. I liked the idea of a small point of contact so thats how I did it.
zfastmalibu
New member
Yes.
cloudrepair
DWG
I'm about to. Does reaming at 250 rpm cut smoother or easier than say70 -100 rpm?
cloudrepair
DWG
I'm about to. Does reaming at 250 rpm cut smoother or easier than say70 -100 rpm?
JerrySharrett
Senile Member
Reaming at 250 in stainless will work as long as you realize that pausing with the reamer against the metal but not cutting can cause work hardening and a big mess. Stay under 100 rpm especially in the stainless barrels to avoid work hardening the metal. Old machinists called this crystallizing.
Get yourself a good book on the mechanics of machining and read up on work hardening/cold working metals.
Learn how to calculate cutting speed by SFM (Surface Feet Per Minute not RPM).
.
.
cloudrepair
DWG
Thanks that brings back memories of twenty years ago when I first started programming and operating cnc mills with a simple cad program we were making coring bits with diamonds and a carbide,nickle,molybdenum matrix.
a part I have in the machine now about 300 pounds of 4140 when I started
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JerrySharrett
Senile Member
Greg Walley
Member
Pusher or dead center
I don't think I've ever seen a barrel reamed using floating reamer holder with the chamber on-spec. Usually they are oversized (>0.001") and elliptical. Often times, they cut larger in the back end of the chamber. They can also be oval or lobed. Ultimately the problem is the bottlenecked chambering reamer itself combined with a standard floating holder. A typical floating holder works fine with straight chucking reamers removing a few thousands from a drilled or bored hole, not with a bottlenecked chambering reamer...which in some ways acts more like a forming tool.
A floating holder you might look into is one that works on rollers rather than balls and has tension adjustment. The rollers help eliminate the stick-slip friction inherent in the standard floating holders. These are available from the high-end tooling makers like Kennametal, Monaghan, Big Kaiser, or Cogsdill. The latter company specializes in this technology. These holders are very expensive, and they even make them with hydraulic chucks attached.
I tried a high quality one made by SMP that had angular and radial adjustment, and I wasn't happy with the results. A better solution would be an adjustable holder that allows one to dial in the tool for radial and axial misalignment, and allows you to lock it down rigid. Although the drawback of locking the tool down rigid is if there is an alignment problem with your 'Z' axis travel, in that if there is excessive sag or droop within the distance of the required travel, the reamer won't cut a qualified hole.
In the long run, you're better off using a dead-center with a properly aligned tailstock with a quill that has no play, or using a pusher type arrangement as described by Dave Tooley et. al. Even with a pusher, the tailstock should be reasonably aligned with the rotational and axial center of the work, and the pre-drilled hole should be bored true.
Greg Walley
Kelbly's Inc.
I don't think I've ever seen a barrel reamed using floating reamer holder with the chamber on-spec. Usually they are oversized (>0.001") and elliptical. Often times, they cut larger in the back end of the chamber. They can also be oval or lobed. Ultimately the problem is the bottlenecked chambering reamer itself combined with a standard floating holder. A typical floating holder works fine with straight chucking reamers removing a few thousands from a drilled or bored hole, not with a bottlenecked chambering reamer...which in some ways acts more like a forming tool.
A floating holder you might look into is one that works on rollers rather than balls and has tension adjustment. The rollers help eliminate the stick-slip friction inherent in the standard floating holders. These are available from the high-end tooling makers like Kennametal, Monaghan, Big Kaiser, or Cogsdill. The latter company specializes in this technology. These holders are very expensive, and they even make them with hydraulic chucks attached.
I tried a high quality one made by SMP that had angular and radial adjustment, and I wasn't happy with the results. A better solution would be an adjustable holder that allows one to dial in the tool for radial and axial misalignment, and allows you to lock it down rigid. Although the drawback of locking the tool down rigid is if there is an alignment problem with your 'Z' axis travel, in that if there is excessive sag or droop within the distance of the required travel, the reamer won't cut a qualified hole.
In the long run, you're better off using a dead-center with a properly aligned tailstock with a quill that has no play, or using a pusher type arrangement as described by Dave Tooley et. al. Even with a pusher, the tailstock should be reasonably aligned with the rotational and axial center of the work, and the pre-drilled hole should be bored true.
Greg Walley
Kelbly's Inc.
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cloudrepair
DWG
I think rock a lot of it was for the oil industry
cloudrepair
DWG
Thanks Greg. the input is much appreciated
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S
shortgrass
Guest
With all due respect, Mr. Walley,,,,,,,,,, if I've only learned one thing in my 43yrs as a job shop machinist, it's that if you work inside of a 'bubble', where there's no outside in-put from other experienced machinists, some day you may meet up with someone who has a faster/easier way. I've found it is always advantageous to work with/around another experience machinist. You may just see something that you haven't thought of in your travels. "Tunnel vision" is to be avoided.....
WHAT th'?
Butch Lambert
Active member
Simple question, how can you cut an oval chamber?
S
shortgrass
Guest
only Al would grind the tang off of taper shank drills!
As thick headed as you are, Al,,,,, I wouldn't expect you would "get it". I chamber with a floating holder of my own design that I made right here in the shop. I pulled previous experience and observations and put one together, and it works very well for me. I may only chamber 3-4 barrels a month, but I don't remember the last time I cut an 'over sized' chamber. I've been using my holder for at least 15yrs, now. There's always 'another way'. If you'd have ever worked around and with other experienced machinist you would understand.
As thick headed as you are, Al,,,,, I wouldn't expect you would "get it". I chamber with a floating holder of my own design that I made right here in the shop. I pulled previous experience and observations and put one together, and it works very well for me. I may only chamber 3-4 barrels a month, but I don't remember the last time I cut an 'over sized' chamber. I've been using my holder for at least 15yrs, now. There's always 'another way'. If you'd have ever worked around and with other experienced machinist you would understand.
Greg Walley
Member
Shortgrass...I agree with you. There is always something to be learned in the machining trade from those who have extensive experience. I have a few friends and acquaintances who run job shops, and are retired tool and die makers. They have taught me many things about the trade that I would have never learned otherwise. I am effusively grateful for the privilege of gaining this knowledge. Yet even the teaching of this knowledge isn’t always sufficient because only “hands-on” training will do for mastery of the craft. I’m sure that you could teach me a thing or two or three because you’ve been in the trade since I was in the first grade.
Notice that in my post, I didn’t say “one can’t” or “it is impossible” to get a good chamber with the tooling in question. Nor do I want to denigrate anyone’s work or any particular manufacturer’s tooling. Maybe I should have worded my post differently. I simply wanted to convey that quite a few chambers that I inspected weren’t within spec. These particular chambers were finished with a floating reamer holder. Other chambers not finished with a floating reamer holder that I have inspected do not exhibit these flaws. I’m not certain if it was the technique used with the tooling in question, the nature of the tooling itself, or a combination of the two that created the faulty chambers.
Many of the questions that have been asked and answered on this forum are from hobbyists. Often times they don’t have access to high-end machinery or tooling, or the knowledge of how to use it effectively for making a precision chamber in a barrel. I’m simply giving my opinion of how they can go about doing the work properly with a minimal of fuss and investment.
Greg Walley
Kelbly's Inc.