Lock assembly help and progress

[brokenflint]

I've graduated from plate wacker 101 straightening class and have fixed the warped plate, on to breaking new ground, actual assembly. I've never assembled a lock before, so I'm in the process of collecting the necessary tools.  The following is a list from the old John Bivins rifle article and some notes I've gathered.  This look like it will allow me to assemble the lock? Or will I need something else, if so I would appreciate additional advice or easy of assembly tricks.
        Drill bits: 5/64", 7/64", 9/64", 11/64", 15/64", 5/16", #19 and #29,
        Taps:  8-32 and 1/4-20  tap wrench
        Reamers: 5/16" & 11/64"
        Files: Pillar 1/4 x 8" x #4 cut and #0 cut
        Bivins assembly jig and drill press vise
        Center punch, small C-clamp, special counterbore w/ .136 Pilot.
I have access to a drill press, 1x42 belt sander and 2 x 72 belt sander as well.

Couple of questions on the sequence of events also.  Would it be beneficial to actually more or less finish up the filing and stoning work on parts prior to actually drilling holes? I would think this would produce a better fit, as in the pan and frizzen fit. What do I look for in taps and reamers?  2, 3 or 4 flute for taps?  This one really has me going, how do you ream a hole if the reamer is larger than the drilled hole?  Should the reamer be parallel the entire cutting edge or are these tapered then transition to parallel so that it can enter the hole then ream to correct size?  I've been looking thru the MSC catalog so if you have favorite tools or ones that work better than others, I'll gladly take suggestions. 

[keweenaw]

Your questions are too long to answer. On reamers, they are designed to enlarge a hole so you drill a hole, say the one for the tumbler 1/64 to 1/32 smaller than the final size and then enlarge it with the reamer.  Before you buy your reamer, make sure what sizes you'll need for the tumbler.  The large and small shafts on the tumbler need to be aligned and concentric. To do this I grab the small shaft in a collet chuck on the lathe and turn the large shaft to final diameter.  If it cleans at 5/16", great, if not I usually go to .302", in which case I would need a .302" reamer for the plate.  After turning the large shaft, grab the tumbler by the large shaft in the 5/16" size collet in the lathe and turn the small shaft to concentric to the large one.  Again, what diameter will depend on what it takes to clean it up.  When you're turning the shafts you can cut a small relief bolster on either side of the tumbler to reduce the bearing surfaces against the plate and the bridle.  Because it's necessary to have the hole in the bridle concentric with the tumble hole in the plate, I then fit the bridle to the plate with both the top screw and sear screw.  I make a bushing to tightly fit in the tumbler hole of sufficient length to slide through the plate and rest against the tumbler.  The bushing should have a hole in it of appropriate size for whatever pilot hole you need for the small tumbler shaft - this will be smaller by about 1/64" than the final hole size as once you've drilled the bridle you'll ream it to final size.  You will, of course, have filed the inside surface of the bridle before you do this and will also have adjusted the length of the standoff to whatever is appropriate for the thickness of your tumbler.

Fitting the frizzen is a chore.  You need to do some filing to make the tail of the frizzen fit tightly between the plate and the pan bridle so file those surfaces first.  Then rough fit the frizzen to the pan.  You'll need to file both the bottom of the frizzen and the top of the pan.  Once that all fits you're ready to drill the hole for the screw.  When I do this I put a very narrow piece of paper about .003" thick between the very back side of the frizzen, (by the face) and the top of the pan and then clamp tightly.  Drill your hole through plate, frizzen and pan bridle at the same time using the #29 drill.  Rather then enlarging the holes in the plate and frizzen with the #19 clearance drill, I enlarge those holes to clear the screw body with a #19 reamer.  The last step is to counter bore the plate from the inside with the appropriate counter bore for you screw head.  The reason I drill with the back of the frizzen slightly wedged up with the strip of paper is that I can now do the final fitting of the frizzen to the plate.  It's very hard to get a perfect fit otherwise.

Tom

[Stophel]

Reamers are not the least bit necessary for lock building.   

If it's a Siler, I usually drill the hole out to .299" (I think that's right, I don't have my stuff in front of me...I believe it's a letter N...), and turn the tumbler down to fit it.

[Acer Saccharum]

Reamers are not the least bit necessary for lock building.   

Oh, just been punched in the gut, Stoph. As a machinist, a reamer will make a hole round, having six flutes. A drill will sometimes make a hole round, having two flutes, (and not much peripheral support with those flutes, I might add). I have seen a drill set up harmonics, and I end up with an egg shaped hole. A reamer will straighten that out. But if you hope the next drill size will improve the roundness, you are sadly mistaken. It will only follow the egg, and not make the hole round.

I love writing sometimes. Especially to Stoph.

[Stophel]

You know, I have never even seen a reamer.

Never had a problem.  And I can tell you, my locks are assembled FAR better and more "close" than ANY "store bought" lock.   

They're too good really....I should charge $500 just for a lock...

[Stophel]

Now you've got me lookin' at 'em.

#@!! $#@*! 70 bucks!

I don't even see how they work.  It would have to expand while it's cutting ?

[Dphariss]

Reamers are not the least bit necessary for lock building.   

Oh, just been punched in the gut, Stoph. As a machinist, a reamer will make a hole round, having six flutes. A drill will sometimes make a hole round, having two flutes, (and not much peripheral support with those flutes, I might add). I have seen a drill set up harmonics, and I end up with an egg shaped hole. A reamer will straighten that out. But if you hope the next drill size will improve the roundness, you are sadly mistaken. It will only follow the egg, and not make the hole round.

I love writing sometimes. Especially to Stoph.

Thank you.
Drills remove metal at amazing speed.
But I tend to ream holes I care about.
In metal anyway.
Dan

[flehto]

When I was on the bench  {tool & diemaker}, if a reamer wasn't available for the size of the hole, the cutting edges of a suitably sized drill were rounded  and this was used to "ream" a hole that was 1/64"-1/32"undersize. This type of drill only follows an existing hole as does a reamer....Fred

[billd]

I agree with Acer.  A drill in thin metal can cut a egg shaped hole or a triangular hole.  You can get reamers for a lot less than $70. More like $20. to $30.   A carbide tipped expansion reamer is in the $70. range.

Bill

[brokenflint]

Thanks all for the responses so far, still I will need help on the use of reamers.  Are these used under drill press power or are they used by hand as with a tap wrench?  It still is not making sense to me if the have a taper or not, so they can fit in the drilled hole to start the reaming process.  I am planning to leave the jig set up on the drill press, chuck the reamer and cut by hand by turning spindle, this work?  Use Tap Magic or such with a reamer?

I think I will proceed with doing most of the cleanup of flash / casting scale and then rough fitting. 

Brokenflint

[Curt Larsen]

Im no machinist--I wish I was sometimes.  If you are building one of Jim Chambers Siler locks, I think he has some pretty good instructions for assembly and the drills you will need.  All of the advice above is pretty good.  I've put together a few locks (Silers and old DGW ones).  My biggest task is getting a tight fit between the frizzen and the pan.  If you're doing a lock from TRS parts, I would think you are on your own.  I built my very first lock from a DGW kit with no instructions and to my amazment it came out fine and functions well to this day--sort of monument to good luck.  I don't think I've ever seen a Bivens lock jig.  I just use the vise on my drill press for the really critical frizzen hole.  Drilling the hammer screw hole on the tumbler can really be a pain if it isn't centered properly.  I'm a lucky novice still so listern to some of the machinists.

Curt

[brokenflint]

Curt   The Bivins lock jig is one that is pictured in his Rifle series of articles which I scaled from the photos and made.  This lock is not a Siler and is a fairly rough casting, no instructions.  I have a copy of Jim C's instructions so I can follow along to some extent.  Once I get the website hosting worked out (probably next month) I can post some pics of this and the polishing work on Colonial Va lock. 

Brokenflint

[Dphariss]

Thanks all for the responses so far, still I will need help on the use of reamers.  Are these used under drill press power or are they used by hand as with a tap wrench?  It still is not making sense to me if the have a taper or not, so they can fit in the drilled hole to start the reaming process.  I am planning to leave the jig set up on the drill press, chuck the reamer and cut by hand by turning spindle, this work?  Use Tap Magic or such with a reamer?

I think I will proceed with doing most of the cleanup of flash / casting scale and then rough fitting. 

Brokenflint

Drill hole perhaps .010"-.040" under size, depends on hole size. Small enough the reamer will "clean" the hole.
Follow with the reamer.
If you ream with a tap handle the hole will likely be out of round etc etc.
Use some drilling/tapping fluid.
Reamers often like to be run a lower speed than drills.
The reamer will produce a hole very close to the size you need. You can ream a hole .001" or so under and drive in a pin that will not come out. A .092-.091 reamer will make an interference fit with a 3/32 piano wire.
I drill aluminum 5/8 then ream to a size that allows a 11/16 drill rod to just slide fit or slightly tighter.
A drill will not make a hole to this precision.
I ream most holes in making locks. tumbler hole in the lock plate, frizzen pivot, holes in links. Anything I want to be properly sized.
http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=2048932&PMT4NO=61833882
Is a USA made  .299 chucking reamer for 29 bucks.
Like everything else this stuff has gone up a lot the last couple of years.
Chucking reamers are available in .001" increments from MSC.
If you intend to measure and work to .001" you also need a micrometer to measure with.

Dan

[billd]

A reamer is usd just like a drill in a drill press. You want a "chucking reamer". Drill the hole .010 to .015 undersize and then ream it to the correct size.  Some cutting oil should be used. For a lock I would only ream the tumbler hole and the hole the frizzen pivots on.  

Some reamers are adjustable, but not much, only about .005. These are used for holes requiring slip or press fit tolerances, like locating pins for fixrures. These are called expansion reamers. They are priced in the $70. range.  Check out www.mscdirect.com  Do a search for chucking reamers.  MSC is not the cheapest place, but they have what you want and and the service is great.  

Bill

[smart dog]

Brokenflint,
I would strongly recommend that you buy copies of Kit Ravenshear's booklets "Craft and Practice Part 1" and "Metalwork Part 2".  They are very cheap and I think Dixie and TOW still carry them.  Both have a lot of good information and tips for building locks from castings. I think you will find some answers to your questions in them.

dave

[Dphariss]

Im no machinist--I wish I was sometimes.  If you are building one of Jim Chambers Siler locks, I think he has some pretty good instructions for assembly and the drills you will need.  All of the advice above is pretty good.  I've put together a few locks (Silers and old DGW ones).  My biggest task is getting a tight fit between the frizzen and the pan.  If you're doing a lock from TRS parts, I would think you are on your own.  I built my very first lock from a DGW kit with no instructions and to my amazment it came out fine and functions well to this day--sort of monument to good luck.  I don't think I've ever seen a Bivens lock jig.  I just use the vise on my drill press for the really critical frizzen hole.  Drilling the hammer screw hole on the tumbler can really be a pain if it isn't centered properly.  I'm a lucky novice still so listern to some of the machinists.

Curt

If you like building locks you should invest in a lathe. If only a small bench from Grizzly or Harbor frieght.
It makes doing precision work on tumblers, or making better ones, making screws (many finished locks need "better" screws to function right) etc etc lots easier.
Clean up the frizzen and pan mating surfaces so they fit pertty well then clamp the frizzen in place and drill it through the UNDERSIZE hole in the plate. Now ream it and the plate to size that gives a tight fit on the screw. Use a tap drill for the threaded part. Fit the frizzen spring. Install the frizzen and go to work. If you have a tight screw fit the spring will not move the frizzen from its position without a spring. But try it with the spring in place to see if you can do the fitting, or most of it with the spring off the lock.
Using Magic Markers I find the high spots I use files and scrapers to get a good fit. This is easier on locks with "waterproof" pans.
Once fitted and the spring installed file the pan and bolster to match each other.
Dan

[brokenflint]

In this thread (http://americanlongrifles.org/forum/index.php?topic=2774.0) Sam installed some tumbler bearings and apparently you can use these for the frizzin roller also.  Sam can you tell me what they are and where to get them, may be a few years before I can figure out how to do this, but I'd like to know about em    Sam, Next time you're making one of these can I come and look over shoulder    Larry   You going to have the lock from this thread at Friendship for the lock sparking photography?

Broke

[Larry Pletcher]

In this thread (http://americanlongrifles.org/forum/index.php?topic=2774.0) Sam installed some tumbler bearings and apparently you can use these for the frizzin roller also.  Sam can you tell me what they are and where to get them, may be a few years before I can figure out how to do this, but I'd like to know about em    Sam, Next time you're making one of these can I come and look over shoulder    Larry   You going to have the lock from this thread at Friendship for the lock sparking photography?

Broke

Broke,
Yes, it will be with me.  I want to time it before Friendship and then get it on high speed video.  I might have a chance to get it videoed before Friendship.  I want to offer the Olympus fellow to meet me before the shoot to get our act together early.  Might save us set up time.  If that happens, I'll use Sam's bearing lock as the subject.  When we did this in 07 I spent a forenoon early with the Olympus rep getting things like lighting worked out.  At 5000 fps it takes much light.

Regards,
Pletch

[Stophel]

If I could find one about .305", that would be fantastic.

MSC has an absolutely impossible online catalog. 

[Stophel]

I just ordered a .303", .305", and .306" from McMaster Carr.  The exact size I'm not too worried about, I just need something between about .300" (to clear out the as-cast hole in a Siler plate), and .308" (+ or -), which is about the size that Chambers sends out Siler tumblers.  I don't want to just drop in the tumbler as-is.  I want to turn it down some, which makes future replacement easier.  It leaves you some leeway for fitting.

[brokenflint]

Chris   What did you order, reamers or the bearings?

[Stophel]

reamers.  $22 and change a piece.