Floating Reamer holder verse rigid.

[tobnpr]

I use Manson's, which is basically a big flat pusher.
Tried shop made one with a ball bearing against a flat, and it cut oversize. You can't push on a ball from any point other than dead nuts center/straight or you influence it and it'll exert side pressure against the reamer which is a no-go. That, and chatter. I know it works for some, but didn't for me.

 

[DShortt]

Care to share a few pics of your home made floating reamer holder? Just curious is all. What a great thread! Let's keep it going to have something to stimulate the brain cells. What few are left! Lol!
Paul

Sent you a message.

 

[DSMWerks]

I use a JGS floating holder.i keep the quill extended to minimum.i have the barrel in the spider chuck extended to minimum.the less over hang the better.when everything is dialed in and pre bored I start to ream.thumb and finger just resting on reamer so I can feel how it's cutting.constant flow of oil keeps the chips rolling back.no problems keeping the reamer inline when retracting and reinserting.i keep the lathe running and oil flowing.tailstock is true.chambers come out consistently concentric and true when checked with the interapid.this way works the best for me...it may not for others..good luck.

Sounds like a good plan. I read the JGS holder does try to stay centered and not drag on retract or plunge in. My current ones do not. How deep are your pecks? Do you do like a .050" peck and a short .025-.050" retract to flush a few chips away and do another .050" peck before retracting all the way or full retract every peck. I have not got my flush system up and running yet but with 60-80 psi I'm wonder just how much the chip with evacuate. Either way it will take 2 hrs of the old peck .025", wipe, clean, brush on oil operation.

 

[LVLAaron]

I've never thought about it, but the JGS does stay centered. I've never had it drag on a chamber.

Regarding peck depth... Depends on the cartridge and how much I pre-bored out. If I got the pre-bore close to the reamer size, you can go at it like crazy. The chips will be small and flush out really easily. Once you start fully cutting the neck/freebore/shoulder the chips get a little bigger and don't evacuate as easily.

I just keep track of where my right hand is. if I retract, I count revolutions, clear, and go back in just short and slowly start cutting again.

 

[Walt Krafft]

Never pull the reamer a little bit and go back in. That is how you will ring a chamber. Always pull it all the way out and let the flushing push all the chips completely out of the chamber and off of the reamer.

 

[butchlambert]

Never pull the reamer a little bit and go back in. That is how you will ring a chamber. Always pull it all the way out and let the flushing push all the chips completely out of the chamber and off of the reamer.

Yes sir! You want to know how I learned it?

 

[Carl S]

Sounds like a good plan. I read the JGS holder does try to stay centered and not drag on retract or plunge in. My current ones do not. How deep are your pecks? Do you do like a .050" peck and a short .025-.050" retract to flush a few chips away and do another .050" peck before retracting all the way or full retract every peck. I have not got my flush system up and running yet but with 60-80 psi I'm wonder just how much the chip with evacuate. Either way it will take 2 hrs of the old peck .025", wipe, clean, brush on oil operation.

I prebore as much material out as I can.when I start to ream I'm feeling what the reamer is doing and watching the chips flowing.i don't specifically aim for a set number on the quill's graduations as regarding each peck before I retract the reamer..feel and watching the chips is key.when I get close to head space dimension then I watch the graduations on the quill.i retract the reamer fully and the chips are washed off with the oil flow.i just give the reamer a quick once over with a tooth brush,oil still flowing.chamber clean,back in and ream.

 

[DSMWerks]

Never pull the reamer a little bit and go back in. That is how you will ring a chamber. Always pull it all the way out and let the flushing push all the chips completely out of the chamber and off of the reamer.

Glad I asked, I've always done a full retract with no flush system but though 4.4 gal/min at 60 psi would be enough to count on chip evacuation.
thanks,

 

[LVLAaron]

I think you'd need cnc pressure/flow to get all swarf out while cutting.

 

[xr650rRider]

Glad I asked, I've always done a full retract with no flush system but though 4.4 gal/min at 60 psi would be enough to count on chip evacuation.
thanks,

When you are effectively plugging up the flow path with reamer, you won't get 4.4 gpm.

Mine is probably 2.5 gpm, will do 60 psig with closed valve. I have an air line with check valves on oil and air. Turn oil feed off, turn on air and that pulse of air/oil flushes all the cuttings off of reamer, when it's retracted.

 

[DSMWerks]

I think you'd need cnc pressure/flow to get all swarf out while cutting.

I can see the mess 300 psi through spindle coolant would be on my lathe! but boy does it work good on hogging deep pockets on a VMC

 

[xr650rRider]

I've never thought about it, but the JGS does stay centered. I've never had it drag on a chamber.

If it stays centered, is it really floating? If it takes much force to make it float, kinda defeats the purpose. But it probably only floats a few thousandths, so you just might not notice that it isn't centered.

 

[LVLAaron]

They can float quite a bit. I believe it's just some soft rubber seals that secondarily keep the shank centered. It takes very little pressure to "make it float"

 

[X Count]

Glad I asked, I've always done a full retract with no flush system but though 4.4 gal/min at 60 psi would be enough to count on chip evacuation.
thanks,

Your system sounds like it has PLENTY of pressure and flow!

People need to consider if you have a high pressure system with limited flow when you pull the reamer fully out there isn't enough flow flush the whole chamber. If you leave the reamer partially in the chamber it reduces the outlet size enough to keep the velocity of the coolant high enough to take chips with it. The flow rate is the same but the velocity is better at taking chips away.

In a home setup there are limitations to both high pressure or a high volume system.

 

[DSMWerks]

I've never thought about it, but the JGS does stay centered. I've never had it drag on a chamber.

I ordered the JGS. The one who dies with the most tools wins!

 

[DShortt]

Check the diameter of the chamber and check for concentricity when you are finished. That will tell you everything you need to know regarding the effectiveness of your clambering method. Absolutely no guesswork or hypothesising involved.

 

[INTJ]

Interesting techniques. I, like many hear, am almost completely self taught. I always keep the lathe running as I insert and withdraw the reamer, with the flush on..........except for the vey last pass.

For the last pass, after I have taken my measurements, I hook the flush back up and flush out the chamber, then turn off the flush. I then run the reamer in and lightly bump it a couple of times to set zero on the tailstock. The I back the reamer out five turns, turn o the lathe and flush, then make my final cut. My chambers always look good.

I did watch one master machinist, with a barely dribbling flush, run the reamer in the whole way in one slow pass at 70 rpm. And the chamber looked fine.

 

[skeeljc]

I am interested in comments on these two "floating" reamer holders.

GTR Reamer Holder (PTG)


Dave Manson


The PTG corrects for angular missalignment only. The Dave Manson corrects for axial missalignment only.

 

[LVLAaron]

FWIW the Gretan holder isn't a floater.

 

[xr650rRider]

I use the Gre-Tan (top one) but you have to have your tailstock dialed in. Mine is deadnuts side to side and height is off .0003" over 12".

From Gre-Tan website

Radial alignment is corrected with this reamer holder. Axial alignment is not. The axial displacement in the ram of the tailstock will provide what is needed. That is if the correct alignment procedure has been preformed to the lathe and tailstock for reaming operations, i.e. chambering for rifles! Tailstock alignment procedure for turning a true shaft IS NOT the same thing and will never give you true center lathe axis thrust for chamber reaming!


Helpful hint: If you don't know how, or your tailstock simply can't be realigned, then one of the manufactured floating reamer holders on the market is what you will need to purchase to correct axis misalignment and give you the ability to ream straight chambers. But, on a floating reamer holder, nothing guides the back of the reamer, it goes where it wants. If the reamer starts crooked, it stays crooked, no matter how the barrel is lined up. It's up to you, my system where you know you're straight, or the others where you hope you're straight.