Arbor Shimming

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jimeast

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I have been looking around for round shim stock to set the arbor/barrel relationship or cylinder to barrel gap. The best I have been able to fin is the following. It's an arbor shim assortment with a 3/8 OD I see the larger Uberti's have roughly a 1/2" diameter and the smaller roughly a .4" diameter. Any suggestions beyond the set I am looking at would be appreciated!!!

http://www.amazon.com/Steel-Arbor-A...&refinements=p_85:2470955011,p_89:Small+Parts
 
Funny you should mention this. Just finished--10 minutes ago--using a 5mm flat washer on a Uberti 1860 Army. In my case, I used it to fill the arbor hole in the barrel. Bought a bunch of these washers and it appears each manufacturer washers are a slightly different thickness. That is great as I found one that was a perfect thickness for this particular gun. My local Lowe's has an excellent assortment of metric washers and they are inexpensive. A bit of JB Weld to hold it--thank Goodness I remembered to coat the arbor with vaseline as I reassembled the barrrel to the frame and put in the wedge. Everything seems tight, waiting for it to cure now.
By the way, a 4mm washer works great on the pocket Colts(at least the Ubertis). Forgot what size I used on the Uberti Dragoons.
 
A surface grinder comes to mind for reducing the thickness of a washer.
 
You guys are trying a little too hard.
Use the washers to get you close, then use feeler gauge leaves to cut out a shim or, if the shim stack is a little too thick, remove material from the end of the arbor. Either way, you can end up with a perfect .002" barrel/cylinder clearance.

I do it about every day.

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks
 
You guys are trying a little too hard.
Use the washers to get you close, then use feeler gauge leaves to cut out a shim or, if the shim stack is a little too thick, remove material from the end of the arbor. Either way, you can end up with a perfect .002" barrel/cylinder clearance.

I do it about every day.

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks
Oh Well!
 
I have only done 4 of them, but I have an assortment of aircraft washers, which come in different thicknesses and only required a little sanding on one to get them right.
Remember that the arbor hole does not have a flat milled bottom, so a larger washer will sit higher on the edge than one of a slightly smaller diameter.
 
Before I got my machine shop set up I shimmed the arbors on my open top Uberti 1860's using only hand tools. Any of you can do the same thing.

You'll need some suitable size steel to make the shim button. By "suitable" this means the same or slightly smaller diameter as the arbor. Find a common bolt that has a long unthreaded shank and cut the head off to use for stock.

I started by forming a slight coned corner on the end of a bit of suitable diameter rod. This "lathe" work being done in a hand drill using a file. The nature of the way the file cuts the metal will provide a consistent chamfer width if you use just about any care in holding the file to the metal with some consistency at all. After the chamfer was cut I used the corner of the file to mark a ring about .08" back from the tip.

The bit was then cut off with a hacksaw slightly longer than the scored ring. I made a filing holder out of a scrap of 1x1/4 flat bar. I drilled a shallow hole that let me drop it down over the shim so I could press down on it and push it along the file by pushing against the edge of the button. This was used to run the shim over a file to dress it down to the score line and square it up. To take more off one side or the other I'd put the taller side facing the handle of the file then put the presser tool over it and push towards the handle. Having the thicker side leading the rest tends to cut more off that side. Once it's squared off and I'm thicknessing the shim I would take a short cut, turn the button a quarter turn and take another short cut and turn again. Keep going with the short cut and quarter turns in sets to keep the button square.

It's just simply trial and test to shorten it until it gave me the proper cylinder gap. If you go too far toss it and try again. Or save it for the next gun.

After that the end of the arbor was cleaned and degreased and the shim degreased. Soft regular solder was used to attach it to the end of the arbor and the cylinder gap checked again. In one case I needed a whisper of filing to correct a slight off center soldering job and in the other no change was needed.

The process for soldering on the button could not be easier. The faces of the arbor and button are tinned with a thin layer of solder first and allowed to solidify. Then place the button on the arbor and center it. Use a nail or some thing long and steel to press down on the button and re-heat the solder until it melts. Hold some pressure on the button with the nail or wire until the solder cools. Otherwise it can float up and shift a little on the puddle of solder.

So.... scrap of round steel rod and a scrap of flat bar for the button holder for filing. A file, hand drill, hacksaw and propane torch for tooling. Some regular solder and flux to finish it off.

Some will say "I can't do that with hand tools! I don't have the skills!". To that I say it's only your time you are risking. And even if you mess up the first shim button or two you're learning as you go and the third or fourth will be just fine unless you're a complete klutz that can't even operate a common pen or feed yourself without risking a poke of the fork to the eye.

You'll be learning as you go too. You'll get a feel for the file and how best to use it. But you'll never get that feel if you don't try.

Soft regular solder is used here instead of silver solder for a couple of good reasons. First is that for this application the soft solder is more than strong enough to do the job. Folks don't give regular solder enough credit for strength when it's used correctly on the proper sort of joint. And this is the proper sort of joint to work for this application. Also the temperature needed to melt regular soft solder is well below any tempering temperature that would affect the arbor steel. Just don't boil the solder and you're fine. So here again any risk is marginal if you pay any attention at all to what you're doing.

If you haven't used a propane torch for soldering before make up a couple of test buttons and solder them to the end of a cut off steel bolt that was used for the buttons. Use the same tinning and re-melt procedure mentioned above to make it easier to get a neat job without lots of excess solder. You Tube has lots of propane torch soldering videos to use as a guide.

The flux is a big part of doing this well. The white stuff seen in the stores now is terrible. Find some proper paste or liquid flux somewhere. It's the only stuff worth using.

The big thing here is that you'll never know if this is beyond you until you try. And once you try you'll learn. And at most you'll toss out two or three failed attempts learning the tricks and techniques to shape then flatten the ends to make a good shim button.
 
25cschaefer, OK, you're right. John would use a file and would mark the high spots and file them off. I think his instructor in bench metal was more accomplished. Dan and I were trying to bend our hammers by heat 'n beat. John looked at us dumbfounded and said, "What are you doing? Just use some wrench and tweak it." Darn if John wasn't dead on about that one. I wish he taught bench metal.
 
I was making a barrel lug for my elephant gun today and one of my students stopped me as if I was about to loose a finger and asked if I was going to get the mill back to my numbers (I was 0.0004 out) and lock the bed down. I told him that we are building precision rifles, not rockets, and it will be bored to size anywho. He looked dumb founded so I had to explain the time=money thing.

Back to the topic: BCrider is 110% correct - that is a good write up and great words of encouragement. You have to do it before you can do it well, fire up that torch and watch a couple youtoobits about how to use a file.
 
With all due respect, its a lot easier to fill in the arbor hole with steel and dress the end of the arbor for your desired barrel/cyl clearance (no torches/ solder or machine shop needed) rather than elaborate decorations on the end of the arbor (you know, that time is money thing).

I for one wouldn't say 110%.

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks
 
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Arbor/Barrel Fitting

I'm coming to the conclusion it makes more sense for me to fit the shim to the hole in the barrel. I came to this conclusion when it occurred to me that if I do this, I can have two barrels for the same firearm, with less work using this method. I think (just thinking) it would work well for me to try out an 1860 with a long and short barrel. I can pick up a 5-1/2 inch barrel a lot cheaper than a 2nd 1860.

I will also have the freedom to add the adjustable stop to the arbor/wedge interface that 45 Dragoon also speaks positively about.

I do like Pettifogger's method, but this may make more sense for me.
 
As the old story goes there's certainly more than one road to Rome....

A suitable washer or other shim that produces the correct gap could indeed be dropped into place along with a dab of epoxy. Then with the arbor lightly slicked up with grease as a release agent wedge the works together until it cures. The washer and hole having been suitably degreased prior.

I actually did run one gun with a loose shim for a short while. But the old memory being what it is I went to show someone how easy it is to strip down an open top. The barrel lifted away with a flourish and we both noted a little dot of silver falling away and hitting a stone in the gravel. Never saw it after that. And that would be why I'm a fan of securing the shims with something to one of the bigger and harder to lose parts. In the barrel or on the arbor. Pick your poison. But stick the darn things to SOMETHING! ! ! ! ! :D

25cshaefer, I thank you for the vote of confidence. And you're right on in thinking that much of the intent of my post is to point out how much can be done with basic tools if one is willing to risk doing the job a couple of times for the sake of learning and doing. And a little thing like fitting and adjusting a shim is one of those perfect times to take up the challenge since it offers no risk at all to the gun itself.

Few of us here are doing this for a living like Mike is. So a bit of extra hobby time in exchange for learning a new skill is hardly a time vs money situation.
 
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BTW, I finally clicked on the link to the shim pack as provided in the first post. Take note that the washers supplied are in a "full hard" state. That means that they are going to be rather brittle unless the buyer takes the time to temper them back a bit. I could see opening up the gun one day only to have a bunch of shattered bits of steel fall out of the barrel hole if this isn't done.

So all in all I'd suggest that anyone considering that kit save their money and just use regular small machine screw washers or make up the button I've suggested from a bit of a bolt. Soldered to the arbor or glued into the barrel makes little difference one way or the other.
 
Jim, you are right in your assumption. I have done many "multiple barrels" for customers and raising the bottom of the arbor hole for several barrels to meet the same arbor is (in my view) the only way to accomplish the feat and end up with a .002" clearance no matter which barrel is installed.
Also, you are correct with having the arbor end free to install a set screw (which has nothing to do with correcting the arbor length) so you can keep your wedge position the same.

I like to keep things simple and have as many options available as possible.

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks

BTW, I have no animosity toward BC, we've been through this before and we just like our on way to achieve the same goal.
 
Fella's I have been following this thread with great interest , my Pietta 1860 doesn't have a big C/B clearance, mine is .004-.005.
I'm just having a lot of difficulty visualizing this whole "shimming process".

Does anyone here have any pics or video of the "operation" ?.
Sometimes the written word doesn't do it for me,,, I need pics..:confused:

I googled it but didn't really find anything that simply explained it.

I new those 5 years of collage were wasted on me,,,.:evil:

Thanks gents,,, &,,,, ladies..
 
Remove the barrel and cylinder. Now put the barrel back on the arbor but turn it sideways. With the wedge out of the way push the barrel backward as far as it will go. Usually you will find that the barrel goes too far because the hole in the barrel is too deep, or the arbor too short (usually the former).

This discussion concerns how to put a shim (or more so a plug) in the arbor hole in the barrel so that when the arbor bottoms out the cylinder gap will be about .002-.004.

Clear as mud?
 
Hmmmm, I keep seeing in my head a bigger clearance / gap if a shim is pushed in the arbor hole,,,:cuss:
 
mr wack,
What's in your head is probably correct for your Pietta. So, in your case, dressing down the arbor is what you would do get to a smaller bbl/cly clearance. With an Uberti, there is space between the end of the arbor and the bottom of the hole when assembled. So, it needs shims to fill the void. See?



Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks
 
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Oh!! ,, oh !!!,, ok I got it now, I was looking at mine and wondering how in blue blazers does this work but I have a handle on it now.
Not "clear as mud" now, thanks Old Fuff your post gave me some relief from my madness , Mike made it clearer by saying maybe not in my case, betwixt the two of you I got it...:evil:.
Thanks fellas.
 
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