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ahidley
12-02-2016, 06:48 PM
When using an adjustable hand reamer, how do you feed it in so it's square to the hole? In my entire life I could never achieve that.


I guess the same thing applies when starting a tap by hand too.

Toolguy
12-02-2016, 06:53 PM
The way I've always done it when making something, is to support the handle end with a center, either in the lathe tailstock or
collet or chuck on the mill.

Andre3127
12-02-2016, 06:55 PM
Hand reamers are tapered at the nose to ease in straight starting, whereas machine reamers are full size right away and are harder to keep inline. Do you actually have a machine reamer?

BCRider
12-02-2016, 06:59 PM
"Carefully" ?

I'm only half joking too. The idea is to sort of let it float by turning it but with a looseness to your hold and to how you turn it so it seeks its own center.

If the application allows for it drilling the hole to be reamed the one size under to allow for the meat to be removed then drilling a "counter bore" of roughly one diameter depth of the proper size hole will or should give you enough of a starting pilot to get the reamer running true enough that with a little of that "care" again it'll find it's own center more easily.

You might also be able to start it in the drill press much like many of us do with a tap to aid in getting a nice alignment to start out. And another option is to make a starting block which is a lump of metal with the right size hole for the reamer that you hold in place and the guide acts like that counterbore idea to aid in getting the reamer started correctly. You'd likely make that up on the lathe, or maybe the drill press once again

ahidley
12-02-2016, 07:25 PM
This one in question is a pivot pin hole in a compact tractor backhoe. I don't think the tractor would like it if I tipped it and put it in the lathe..

Somewhere along it's life the pin was replaced by a bolt. The bolt made the hole anything but round.
The easiest way was to use an adjustable hand reamer and keep making it larger untill it cleaned up the hole. I then made a new oversize pin.

Keeping the reamer straight was impossible. There were two holes to be reamed that were welded into a square tube. Thus both sides had to be inline so the pin would go through....

enl
12-02-2016, 07:54 PM
In similar situations, I have welded or clamped guide jigs on, similar to a drill jig, but soft enough to ream. Bore the jig for the reamer, clamp in line, and it gets the reamer started. Let the guide ream out with the hole. If the hole is wallowed out, then reaming is really not going to give a good result without prep to get the hole near round and in line.

The preferred method is a boring rig, but that requires either having one or spending the money to hire, so is off the table for a lot of jobs.

CCWKen
12-02-2016, 08:10 PM
If they're really bad, dealers/shops cut the bushing part out and weld in another using an alignment pin. That's followed with line boring with a portable boring bar. It's never cheap when the equipment has been neglected.

becksmachine
12-03-2016, 01:36 AM
When using an adjustable hand reamer, how do you feed it in so it's square to the hole? In my entire life I could never achieve that.


I guess the same thing applies when starting a tap by hand too.

I know exactly of what you speak, and the short answer is it is impossible. Your lifetime of experience has shown that, as has mine also.

I would also guess given your further description of the application that you were trying to turn it with an adjustable wrench or maybe a socket on a ratchet? This makes it even more impossible (that is an oxymoron isn't it?) Or maybe I am the only fool to ever try such a thing?

Any kind of single sided, unbalanced application of torque just makes it tip and dig in.

The only manually powered alternative that I have come up with is developing some sort of pilot mechanism. The Chadwick & Trefethen (Critchley) brand reamers have available screw on pilots, they also have solid, long pilot versions that were/are originally intended for reaming electric motor bearings. Or if there is opportunity to support the shank somehow, that will help also.

Using a pilot with a relatively balanced application of torque that can be supplied by something like a tap handle, or a tee handle on a socket, makes it at least possible to make two holes that are at least sort of round and concentric, no guarantees that their centerline will be parallel to anything though.

I have used a magnetic drill press also. Not because the power was needed but just because it would supply a solid alignment for the reamer. But then you have to deal with the problems associated with using an adjustable blade reamer with power, which has it's own set of idiosyncracies. Sometimes very expensive idiosyncracies. Especially when reaming holes in steel. Especially when reaming out of round holes in steel. Can you tell I am somewhat bitter about this issue!!!! :)

Dave

mattthemuppet
12-03-2016, 02:35 AM
Can't you use a pilot on the reamer? Pilot set to the id of the second bushing to be reamed, to keep it straight and centered on the second hole. Then perhaps once you have the reamer started in the second bushing, slip a sleeve over the wrench end of the reamer. Od of the sleeve = id of the first bushing, id of the sleeve = od of the solid part of the reamer. Just an idea, never done this myself.

ahidley
12-03-2016, 03:20 AM
Becksmachine. I did use a tap wrench that was about two and a half feet long. I learned long ago that things break unless the force is equally distributed as I'm sure you know too.

So maybe I should rephrase my question. What the hell are adjustable hand reamers used for, and how are they used?

I've used them under power many times and they worked great as long as you very gingerly used them. Don't ask how I know....

Boostinjdm
12-03-2016, 03:47 AM
If they're really bad, dealers/shops cut the bushing part out and weld in another using an alignment pin. That's followed with line boring with a portable boring bar. It's never cheap when the equipment has been neglected.

I have replaced many pivot points on all sorts of things this way. If you're lucky no reaming required. Many times I'll fine tune the fit with a die grinder and a drum shaped flap wheel. As far as your reamer question, mine has a non cutting, undersized portion at the tip for alignment.

BCRider
12-03-2016, 03:58 AM
I'd assumed that you were starting with a more or less round drilled hole. But it sounds like your specific situation is that the hole is oval or even kidney shaped. So the firs step would be to drill it to something round that pulls the hole size out to match the longest dimension of the wallowed out shape. and slightly under the desired size. THEN ream it using a guide bushing made in a lathe or drill press that is clamped tightly to the hitch so it guides the reamer.

The trouble with that is that it's likely to end up being anything but centered too. That's where your guide bushing comes in again. Make the bushing with the drill size you need and make it large enough or weld a tail to it to allow you to clamp it securely in position to guide the drill so it cuts where you want it to cut and does not just seek out the line of least resistance off to one side or other. With that done ream out your guide using the reamer on a drill press or in the lathe or some other guided way. Then re-clamp and use it to ream out your hitch and it's ready for your new custom pin. Or alternately if the hole will leave too little an amount of metal it's ready for a weld in place bushing that is a close fit. Then ream that out to the proper size using a clamped in place guide bushing.

becksmachine
12-03-2016, 05:11 AM
Becksmachine. I did use a tap wrench that was about two and a half feet long. I learned long ago that things break unless the force is equally distributed as I'm sure you know too.

So maybe I should rephrase my question. What the hell are adjustable hand reamers used for, and how are they used?

I've used them under power many times and they worked great as long as you very gingerly used them. Don't ask how I know....

Misery loves company. :p

I don't know what size hole you were working with, but I would suggest that the descriptor "hand" as used in conjunction with "adjustable reamer" be limited to sizes under, say, 1/4", no more than 3/8" on a good day.

Anything over these guidelines should use "Godzilla" or alternately, "Idiot" somewhere in the title.

Would "Idiot" and "Godzilla" be too redundant? :) Considering that I have them in sizes up to about 2 3/4", I would surely be implicated for both.

Just the contemplation of having a job show up where I had to use one of the larger ones has caused my banishment from the local chapter of AA. Actually using one would probably get me banned by the National organization.

For those folks recommending that you first run a drill through the hole(s) before reaming, we are probably talking about holes in excess of 1" , and with a drill press/milling machine/horizontal boring mill nowhere in sight. If they want to volunteer to hang on to a drill motor that has both the capacity and power to run an 1 1/4" - 2" twist drill, that is trying to clean up an out of round 1" hole, I would suggest a much higher paying career in the NFL, or maybe even the UFC.

Now don't take me seriously here folks, it is late and I am just having some fun. :rolleyes:

An adjustable blade reamer is really out of it's envelope working in steel. It can be done, as expressed above, "very gingerly" but they are much more comfortable in bronze or cast iron.

Dave

Toolguy
12-03-2016, 10:04 AM
The only way I can think of to "line bore" something in the field with a chance of success would be to use a chucking reamer with a shank or extension long enough to go through both holes. Ideally, you would grind 45 degree chamfers on the top of the flutes just as they are on the bottom. Then put the shank through the holes with a bushing made to fit the shank and the non cutting or "guide hole". Ream the first hole, then turn the reamer around, with another bushing to fit the shank and the reamed hole. Ream 2nd hole.

The bushings could be made up ahead of time in the shop and brought to the job site. You would be pulling on the reamer rather than pushing, so some sort of pushing mechanism on the cutting end would help, similar to a gear puller. There are chucking reamers that have an expandable end, that you could get a few thou. of adjustment with.

Seastar
12-03-2016, 10:21 AM
I needed to ream new holes in my light aircraft wing struts to replace the fasteners that we're breaking because they were too small. The holes were to attach the lift struts to the wing struts.
Four hollow airfoil shaped struts made of aluminum and one through hole in each.
The factory made the original holes with a jig that insured they were correctly aligned.
All I had was an adjustable reamer and a portable electric drill.
They were a bitch. I drilled just undersized and then carefully reamed in small steps untill the holes were the correct size.
Slowly stepping up in size saved the day.
Took me several hours to do those new holes.
Haven't broken a fitting since.
Bill

J Tiers
12-03-2016, 10:54 AM
Piloted reamers.

Best if you have a pilot and another locator in-line with the hole.

I once reamed the split adjustable spindle nose bearing on a 109 lathe with an adjustable reamer. Worked fine... Piloted reamer with a tapered pilot bearing located in the other bearing, tail of reamer in tailstock center. Worked fine, pretty solid, plenty good enough for the 109. bearing was egged-out (I suppose it really HAD "gone pear shaped").

Since hen I have nabbed every piloted adjustable I have found. Bonus points if they still had their tapered pilot bearing.

BTW, the pilots on them are often extensions that screw onto the end, so it would be possible to make a pilot, and skim cut it when mounted on the reamer, to assure concentricity.

ed_h
12-03-2016, 11:57 AM
As others have said, you could arrange for some sort of pilot to keep the reamer aligned with the other hole. These are some pics of a shop built pilot for an adjustable reamer I used to ream bushes for a motorcycle swing arm,

Ed

http://bullfire.net/Triumph/Triumph10/SDC10619a.JPG

http://bullfire.net/Triumph/Triumph10/SDC10632a.JPG

http://bullfire.net/Triumph/Triumph10/SDC10622a.JPG

old mart
12-03-2016, 01:44 PM
A pivot pin hole in a backhoe is a truly agricultural setting, who cares if it is straight or not.

Toolguy
12-03-2016, 01:52 PM
A closely fitted straight one lasts a lot longer. I read somewhere that Caterpillar specs holes to be.0002 over pin size. That takes a very straight alignment to get a pin into.

becksmachine
12-03-2016, 02:24 PM
A pivot pin hole in a backhoe is a truly agricultural setting, who cares if it is straight or not.

A very good question.

As Toolguy has mentioned, life of at least the pin is greatly affected by even small amounts of misalignment. Obviously bushings also if such are present. It is all about contact area and loads on that area. A misaligned pin bears only on relatively small patches at each end of the hole. If the range of movement is small, the combination will wear/bend it's way into whatever area is necessary to support the load.

Which becomes worse if a joint has frequent small displacement combined with periodic large displacement or continuous large displacement. There is a tremendous lever arm effect, as any misalignment is effectively doubled if the joint is pivoted 180.


And not just that pin and/or bushing(s), but all linkages, cylinders etc. that have any connection to that joint.


Dave

ahidley
12-03-2016, 02:29 PM
FWIW. The hole was originally 1 inch in diameter and after it cleaned up it was 1.09 inches in diameter.