How to checker a hammer spur

[BrentD]

I have a hammer for a long-range muzzleloader that I want to checker using a checkering file. The spur has a complex set of curves that make it difficult to imagine how to jig up something that would serve as a fence or guide for the file.

Does anyone have any experience with this? I could make up something but reinventing a wheel that might be only half as good as something tried and true seems like a folly. Any suggestions would be really welcome.

thanks.

[seagiant]

Hi,
I checker frontstraps mostly on 1911 frames. I use some homemade jigs to get the lines started straight,but then go free hand using "feel" to keep it right!

Just saying with something that small you might have to just go freehand! Good luck!

[pietro]

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https://www.youtube.com/watch?v=QZvhpLzzg-0


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[BrentD]

Yeah, I saw the checkering video already. Unfortunately, there is not much besides the file that is similar to doing a percussion hammer that has curves in three dimensions and has to be cut on the bias to get diamonds not squares. I'm looking for a method of building a jig where simple wire/tie or stick won't do for a guide. seagiant may be right - freehand might be the only way. But I'm going to explore it a bit more before I plunge in

[oldred]

I have done this several times and for me the best way was with the proper riffler files and just doing it freehand. I hold the hammer in a small machinist vise and use a flexible stainless steel straight edge and a no. 2 cut riffler to make the layout moving the straight edge back in precise steps to give the desired LPI then finish with the same style riffler but in the courser 0. cut. I have found my checkering files to go pretty much unused as it seems most of the time when I need them I run into the same problem you are describing but the rifflers make it easy and will do any contour.

[KCSO]

First polish the hamer smoth and shiny and then coat it with layout dye. Then use a narrow ruler cut from a flexible plastic to make your layout lines at the angle you want. Then take a sharp v file and cut your first lines in the hammer all the way around the curves. Then use the checkering file to layout the spacing and finish by deepening the lines with a v file. Shoouldent take more than about 3 or 4 hours the first time around.

[leebuilder]

The craftsman in the video looks like the proper checkering file that Brownnell sells. They are expencive and i would not want to ruin mine. I test to see the material can be checkered with out ruining the file. Then start, the file pretty much does it all as long as you keep consistant angles of stroke. Very easy to use. Never tried any complex contours, riffers would be the way go there.

[BrentD]

leebuilder, the same files that Brownells sells can be bought on Amazon.com for abou 1/2-2/3's of the Brownells price.

I'm going to try to make a jig today. After a bunch of mental masturbation, I think I have a simple idea that has a chance of working. Maybe.

[firebrick43]

Very little elongated 60 diamond metal checkering looks good to me. Square typically looks much better! Only a few high end rifle bolt handles I have seen and they are not 60 degrees but maybe 75?

Never the less a thread restore file can help layout. Put layout fluid on and lay out two base line with a flexible rule (I have Incra ones). Use a sharp new triangular saw file to start the lines and deepen them some. Use your thread file on whatever tpi you want. Just touch it so it scratches the lay out fluid to show you where your next line is and repeat. A sharp divider can do the same. However the majority of work is going to be done with the triangular file, a riffler and a die sinkers chisel to get up to the stop lines and it just takes a touch, good eye, and skill to do.(with a lot of patience) There is no magic file or machine to checker (good looking that is) on a compound curved surface except maybe a five axis cnc machine and the programming would take forever.

You probably don't want to hear it but just stick with standard serrations across the hammer. Much easier to look nice.

[oldred]

Firebrick I have heard that thread file suggestion several times and I have no doubt it works with the right file but I have yet to find a thread file that is not so dull and blunt on the tips that it can be used for this. I bought a Snap-On from a tool dealer but when I took it out of the tube it came in I saw immediately it would not work, since then I have looked at several and even ordered a Lisle brand on the suggestion of someone else but it too has the flat teeth tips. If one can be found that has sharp teeth I bet it would be the cat's meow for doing this and while I have two already, the Snap-On and the Lisle I would buy another one if you have a suggestion?

[BrentD]

Well, after some thought and consideration, here is what I built and how it worked.

Overall, I can see a couple of ways that it can be improved, but it's definitely doable.


http://www.public.iastate.edu/~jessie/PPB/Alex%20Henry/Hammer%20checkering%20jig.jpg

http://www.public.iastate.edu/~jessie/PPB/Alex%20Henry/Hammer%20checkering.jpg

[leebuilder]

First time?. If it is i think you did very good.

[BrentD]

Yup. First. I learned some things. I think next time I might try to pull the file for the first couple of cuts in each direction. There is definitely a "feel" to be acquired. I may need to do a little touch up with a riffler but I think it will be fine if I cut three more lines on the right side. I had a geometry brain fart setting this up.

[DougGuy]

I use the flat checkering file to get the pattern and the lines started. This file is EASY to screw up with because if you slip, it makes a LOT of scratches, so I don't go very far with it before I switch to the single 60° files, medium first, then fine. I take it the rest of the way with the little files. You are doing fine for starting out. Add the other 3 lines so it is symmetrical, then get the 3 file set of triangle checkering files to finish it up with. You can get them so sharp when finished, running the work down your arm will leave a long series of scratches, like a cat did it. This is how good checkering is SUPPOSED to be. Should not be able to see any flat area on the top of the diamonds.

I always use a guide to start out with even if I have to make one for each job. I try to angle the flat file so it cuts on one side, and let that get a good groove then you slowly tilt it so that you are riding in the first groove to keep it aligned and the spacing even, slowly tilt the file as you work so it starts a new groove, work it back and forth until that new groove gets deep enough that you can skip the file over one row or two rows, use the row you just cut as a guide and start tilting the file as it makes a new groove, etc.. This is how you move laterally across a pattern, you won't use a jig after you get the first couple of rows going.

I have done a scad of 1911s, Para frames, hammers, trigger guards, mag wells, mainspring housings, rear of slides, slide stops, etc..

[BrentD]

Doug,
I don't need or even want anything close to that aggressive. I need functional traction w/o ripping the sking off the pad of my thumb. This hammer goes on a serious target rifle. I have to cock the hammer probably more than 4 times for each shot for record. Matches and run a couple days, plus practice days. So something a little less aggressive is where I need to be. I'll try cleaning up with a 60 degree file but it will not be so abrasive that I risk ruining a weekend match over a worn out thumb :)

[firebrick43]

Oldred, can't say it better than Doug did. I don't use a thread file for any thing more than layout. I put a layer of dykem on, layout with thread file, deepen 75% or so and re-dykem. Lightly run thread file back over. If you have gone astray one side of the uneven line will be shiny. As you cut deeper with your triangular file apply pressure to that side to even things back up. I use my used Simmons saw shapening files (4" or 5" double extra slim) for 95 percent and a new one for the last swipe. Use railroad or blackboard chalk to keep from pinning(and clean of oil). A good octagon handle helps as well.

Brent, if you don't want as aggressive of checkering you increase the lines per inch making the diamonds smaller. Something like 20 lpi or even finer. Need a needle file that fine however.

[leebuilder]

I found first few times i went to deep.
GOOD Tip, use a squished rifle casing as a file cleaner. Flatten the neck in a vice then rub acoss the file takes a few stokes for the brass to get the pitch of your file then use it like the old file cards. Realy gets the crud out, makes them look almost new.