Floating reamer holder

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: GlennW, Harold_V

RSG
Posts: 1541
Joined: Fri Feb 04, 2011 9:59 am
Location: Ontario, Canada

Floating reamer holder

Post by RSG »

I'm asking the question if a floating reamer holder for a 5/8" reamer would be practical? Everything I've seen seems to be made for smaller reamers. It's a pretty big ream to be held in one and I guess I'm looking for reassurance that it would be worth making and that it would benefit what I'm doing.

I know some will suggest boring instead....I've tried many times and just don't feel comfortable doing it for anything more that one part for the accuracy I require. I'm looking to be within a few tenths for many parts. The material is 6061 aluminium. Currently I chuck the reamer in the tail-stock and it seems to work not bad but my holetest mic reveals some degree of taper front to back +/- a few tenths.

Bearing fit is good but once anodised the fit requires a press to set the bearings. This is more than I prefer so a machinist friend that owns a speciality grinding company in Ohio made me a hand reamer 2 tenths over .625" to clean up the journal, removing any burr or flanging from cutting the retaining ring grooves. I used it this year on the bearing journals and it worked quite well. The fit this year is among the best I think I've ever had, being able to slide the bearings in by hand.

This is has lead me to wonder if a floating head is even worth making and would it benefit what I'm doing. I'd appreciate any suggestions/thoughts.

RSG
Vision is not seeing things as they are, but as they will be.
earlgo
Posts: 1795
Joined: Sat Jan 29, 2011 11:38 am
Location: NE Ohio

Re: Floating reamer holder

Post by earlgo »

The floating reamer holder that I have was purchased used probably 40 years ago from Travers Tool Co. when they sold used tooling. It was made by the W.M. Ziegler Tool Company Detroit (MI). No Part # other than the tool crib number from the previous owner. It has a #2 MT shank and a #2 MT socket and is 8" OAL. It floats radially about .03 inch but keeps axial alignment.
Ziegler FRH.jpg
The other #2 MT adapter holds smaller reamers with a custom bushing. I couldn't find any info on the internet other than for W.R Ziegler, but this is not the same company.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
johnfreese
Posts: 219
Joined: Thu Jan 21, 2016 2:10 am

Re: Floating reamer holder

Post by johnfreese »

I believe Ziegler and Glenzer companies were bought up. You will have better luck searching for Glenzer. Both tools are pretty similar. There are a few floating holders showing up on flea bay. Another quality brand is Scully-Jones.
SteveM
Posts: 7763
Joined: Mon Jun 27, 2005 6:18 pm
Location: Wisconsin

Re: Floating reamer holder

Post by SteveM »

If you can do the drilling on a drill press, when you install the reamer, there will be no runout, so your hole will be as straight and round as a reamer can make it.

Steve
pete
Posts: 2518
Joined: Tue Feb 10, 2009 6:04 am

Re: Floating reamer holder

Post by pete »

I've no idea if any of this might help, but at 10ths levels of expected and required accuracy EVERTHING is going to count RSG. With batch production of parts like your doing it might work ok or for awhile. But is it going to be something that can be repeated each and every time? Everything I've read so far usually indicates few to maybe no lathes including high end brand new ones will maintain there tail stock alignments to the head stock C/L over the full length of an unworn lathe bed to low 10ths. Even the worlds best lathes are purposely misaligned on both the head stock and tail stock. It's not much, about .001" over roughly 10"-12" high and the same amount towards the operator for both the head and tail stock. That's done on purpose to help compensate for expected work piece weight and cutting tool pressures. With your now used off shore machine it's exact alignments could and probably are just about anything but straight. Maybe there's the odd one that by luck get made and might or do have low 10ths run out, but even Albrecht chucks aren't guaranteed to have less than about .0015" run out, and that's going to vary where it points the reamer depending on the orientation it's morse taper is inserted into the tail stocks taper each time. My Albrecht showed about .001" when I bought it. No doubt that's an extremely low tolerance reamer your friend custom ground for you, but even it will have at least some measurable run out. How much tension you use on the tail stocks locking lever also seems to be important since some of the better? designated Grizzly gun smithing lathes have the ability to use a torque wrench while locking them down. I seem to recall Weiler? lathes and maybe a few other tool room lathes also have that from the factory. So in my opinion there's already more than enough built in inaccuracy's in our lathes to make some kind of floating reamer holder probably worth while just to gain a bit more consistency.

Drilling to me is only a roughing operation if the parts require any level of precision. We all know that a drill just removes most of the initial material out of the way so better and higher precision methods can be used. For what your doing I'd be single point boring under size for that reamer to ensure the hole is actually straight, round and has the recommended material left for reaming since that costly reamer is still going to pretty much follow what's already there for straightness. And any drilled hole with the tail stock is going to be a combination of a bit of luck, material consistency and what your lathes alignments happen to be.But I'd also agree, that boring to a finished exact size is a whole lot more hit/miss and time consuming. That's why reamers were invented as a final sizing tool in the first place. From everything I've picked up through the PM forums, even the cutting lube used can have a measurable effect on a reamed holes finished size. No idea if it works on aluminum, but I stole the idea from one of the Guy Lautard Machinist Bedside Reader books. He recommended loading the reamer flutes with pure baking lard as a cutting lube. The few non scientific tests I tried with it seemed to measure as best I could check to about a 10th or two smaller verses using Reltons Rapid Tap as a cutting lube on mild and stainless steel. It also gave a far better surface finish, almost glass smooth on 303 stainless. Without me testing that lard with aluminum then your on your own about trying it, my guess is probably can't or doesn't return the same results with aluminum. But it's easy enough to try it on a test piece. I also have no idea if it would affect your anodizing process.

If anyone would be picky about what floating reamer holder there using it would be precision gun smiths, so the gunsmithing forums seem to be loaded with posts about which floating reamer holder works the best. There's also more than enough conflicting statements and arguments to make it highly confusing about what does or doesn't seem to work. I've so far not found any shop made design for a FRH that most of those amature and pro gun smiths will agree works well enough to use. I'm sure some can and do work just fine, but it seems almost impossible to nail down which one it might be. Fwiw as John already mentioned some of those better gun smiths do seem to favor the commercially produced Scully-Jones. I dunno, ymmv. Reaming seems to be one of those black arts subjects where almost everybody has a different opinion about what works.
RSG
Posts: 1541
Joined: Fri Feb 04, 2011 9:59 am
Location: Ontario, Canada

Re: Floating reamer holder

Post by RSG »

Thanks for the suggestions guys.

Pete, to answer a question within your post - yes I do bore close to size (.010" - .005" per side) prior to reaming. And the lard idea is interesting, while I doubt I will try it for reasons you mention I have found a difference between using one coolant from another, which was by accident. Changing from one coolant last winter to some new stuff I now use I found the resulting hole feels loser. I could not confirm this accurately of course at the time as I didn't own the proper holetest mic as I have now. I was thinking about making one a holder but after reading some stuff about the gun guys I have to wonder if I need something as accurate as they use as I would imagine they require even tighter tolerances than what I need and therefore need higher precision holder like some of the ones listed above, IDK, just a thought.

For what it's worth, the journals are coming out quite satisfactory however, they are slow to do and I'm trying to make it easier to repeat and like yourself Pete, I'm constantly striving to get the highest level of precision out of myself and my equipment possible.
Vision is not seeing things as they are, but as they will be.
RSG
Posts: 1541
Joined: Fri Feb 04, 2011 9:59 am
Location: Ontario, Canada

Re: Floating reamer holder

Post by RSG »

Earlgo, thanks for the lead. I checked out Travers Tool and while they have them they all appear to be designed for CNC. Nothing available to accommodate a tailstock.
Vision is not seeing things as they are, but as they will be.
pete
Posts: 2518
Joined: Tue Feb 10, 2009 6:04 am

Re: Floating reamer holder

Post by pete »

I'd say your accuracy requirements are as important as what the gunsmiths are RSG. In fact I'd bet any gunsmith would be more than happy with low tenths accuracy for any chamber they were reaming. There use of FRH's are just a work around to compensate for any wear and inaccuracy's in our lathes and allows the reamer to float a bit so it helps to self center the reamer to the bored hole C/L. The only difference is your reamer is a bit larger and maybe slightly more rigid than most chambering reamers might be. But it will still be guided and ream the hole about as accurate or inaccurate as the tool holder and lathes components are aligned. Any misalignment will end up with a measurable taper in the reamed hole. Since that taper will always be larger at the hole entrance side it can be easily checked if it's present with that new holtest or a 10ths dti. Run the dti's ball tip into the hole as far as possible with the lathe carriage, zero the indicators dial and then slowly run the indicator tip back out to the hole edge.

I did a bit of thinking last night. One possible method that might work for you? They make what are called Morse Taper Blanks with soft machinable ends. https://www.mcmaster.com/morse-taper-blanks/ You could mark one of those so it always goes into the tail stocks female MT in the same orientation. Use it in the tail stock and then drill it under size for your reamer shank with a drill held in the lathes chuck, then use a boring head in the lathes head stock and feed that blank in using the tail stocks hand wheel with a bit of drag applied to the tail stocks quill lock. Bore to just barely fit your reamer shank. Add a couple of set screws in from the side of the MT blank to hold the reamer and you then have a known to be true on center reamer holder. Since your only using a single custom sized reamer I'd just leave it in that holder for the life of the reamer. If it were me I think I'd either machine if the reamer shank is soft or grind if the shank is hardened small flats on the reamer shank for the set screws to bear against.
RSG
Posts: 1541
Joined: Fri Feb 04, 2011 9:59 am
Location: Ontario, Canada

Re: Floating reamer holder

Post by RSG »

That's actually a good idea Pete! I was actually going to build a floating holder but this might work as well. The only issue I can see with it is if the tailstock ever gets moved, the unit is garbage then.
Vision is not seeing things as they are, but as they will be.
earlgo
Posts: 1795
Joined: Sat Jan 29, 2011 11:38 am
Location: NE Ohio

Re: Floating reamer holder

Post by earlgo »

Before you start off on building your own FRH here is a picture of what is in the Ziegler model. It may be more complicated than you would think at first glance.
FRH parts
FRH parts
There is a thin bearing between the screw on cap and the MT socket part. Then there is a plate containing 4 closely fitted bushings and 4 balls that are just larger than the plate thickness. The plate has 4 slots and 5 holes. The MT socket part has 2 pins that fit in 2 of the bushings, and the MT shank has 2 pins that fit in the other 2 bushings. There is a large spring loaded ball in the center to hold things in place, centers the socket part but allows the socket part to move laterally. Not seen in the pic but the balls ride on the ends of 8 hardened pins, 4 in the socket part and 4 in the shank part. and are ground flush with the part. If you aren't in a hurry then I could conjure up working drawings of each part and the assembly, but it would take a while. Perhaps you will find something on Ebay that suits. When I got this FRH from the tool company one of the bushings was broken which is why it ended up being sold. Lucky for me it was an easy fix.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
pete
Posts: 2518
Joined: Tue Feb 10, 2009 6:04 am

Re: Floating reamer holder

Post by pete »

Many thanks for the interesting pics Earl. They are a bit more complicated than I'd thought. Or at least that design is.

Yes you'd need to have your lathe leveled and the tail stock already aligned for exact true parallel turning RSG for that MT blank idea to work. But that's easy enough to reset if the tail stock was ever off set for taper turning. Once the TS alignment is correct, I turn and keep a test bar that was turned between centers (the longer the better) with two for want of a better term journals maybe an inch long on each end. I always turn a 60 degree point on a piece of scrap held in the chuck so it's known to be true dead center to the head stock bearings.Then put that test bar between centers, turn, adjust, re-turn etc until your parallel condition is reached. At any time after that place the test bar between centers, zero a 10ths indicator against the side of the head stock journal, run the carriage to the tail stock end and adjust your tail stock to the same zero position on the indicator. It's a fast easy way to get the tail stock back to a repeatable exact & known parallel position. Center drilling each end of a heavy piece of ready rod and permanently locking the larger diameter journal pieces with a pair of nuts at each end, and then parallel turning those would work just as well as a large piece of shafting for that test bar. But the longer the test bar is the higher the amplification is for the accuracy of the tail stocks position.
User avatar
GlennW
Posts: 7284
Joined: Sun Apr 15, 2007 9:23 am
Location: Florida

Re: Floating reamer holder

Post by GlennW »

That wouldn't show vertical error in the tailstock axial alignment either parallel or angular.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
Post Reply