Hand cut dovetail jig?

[WestKentucky]

Has anybody bought/made/rigged a tool to manually cut a dovetail? I know it can be done with a triangular file, but seems that the handheld hack method would not be conducive to quality work. I don’t have access to a mill right now and need to slot a section of barrel and cut a dovetail to hold a threaded block. I’m thinking of using a linear guide with the file clamped down to cut it nice and square.

It’s a SAA clone that I’m tired of fooling with. I ran it hard and kept walking the screw out for the ejector housing and it eventually stripped. Then when I tried to retap it the bottoming tap broke off in the hole. I broke the busted tap with a punch and got that out and have been using the gun without ejector housing for a while. It’s time to fix it, and the fix is going to be a dovetail slot with through-threaded insert. The barrel is not replaceable as there are no long barrels available...ever. I could easily buy a standard length part but I don’t want to.

I have other plans for this gun too, but those plans require much more machinery than I have available.

 

[jmorris]

I have ground triangle files to the proper angle to file dovetails. This way the bottom of the file is “safe” and all you cut is the proper angle into the slot.

Works just as good as a proper dovetail cutter, just slower. I still mill the slot with an end mill to the proper depth first.

That said, I would attempt other methods to repair first. Can you go up a size in screw? Peen, retap, red loctite?

 

[a5werkes]

Here's how Larry does it by hand.

 

[WestKentucky]

Already tried a larger size. The hole is too shallow to get good threads on a larger size. I don’t understand why they did that because the barrel is thick. Everything about the gun was sized and built for 45 colt but mine is .357. The cylinder and barrel are both extremely thick.

 

[BBBBill]

The hole is too shallow to get good threads on a larger size. … the barrel is thick... The cylinder and barrel are both extremely thick.

So why not take advantage of the thicker barrel wall and drill it deeper.
Brownell's use to sell a dovetail jig for filing by hand. Haven't seen it in the catalog for the last 10 years or more, but the do keep contact info for various vendors whose products that they have carried. I was able to get the info from them to get up with the vendors on a couple different products that they no longer stocked.

 

[Mizar]

Depending on your fine motor skills it's doable even without jigs. You need a quality large file, with true 90 degree edges and a good spirit level meter to keep the cut straight. Use a machinist blue and use it more often than you think to check your progress. Once you cut shy (like .002") to the desired depth use a dovetail file (you can make your own by grinding one of the sides) to cut the angled dovetails. Finish the slot with a fine triangular file to get rid of the file marks. It can be done - just level your barrel as best as you can and go slowly while checking your progress after every other cut.

 

[WestKentucky]

Bought a

So why not take advantage of the thicker barrel wall and drill it deeper.
Brownell's use to sell a dovetail jig for filing by hand. Haven't seen it in the catalog for the last 10 years or more, but the do keep contact info for various vendors whose products that they have carried. I was able to get the info from them to get up with the vendors on a couple different products that they no longer stocked.

the tool was a Wheelers jig and it is truly discontinued. They do have good pictures of the unit so it can be reproduced, but I’m not sure I could harden it to be harder than a file. There are other jugs out there, but nothing really seems like it would be hard enough to use it repeatedly. I already have a few projects in mind, so if I’m throwing money I’m doing it right. I may buy another tabletop mill.

 

[Varminterror]

I use a Dixie Gun Works dovetail cutting guide. Ain’t as good as cutting on a mill, and adds a lot more sweat equity to your project, but it’s cheap and it works.

 

[4v50 Gary]

Blackpowder guys have been making dovetails by hand a long time without a jig. Gunmaker Mark Silver can do it faster with a file than it takes to set up a milling machine and do a dovetail cut.

 

[jmorris]

This is one of my homemade “safe side” files and the finished product installing a 10/22 folding rear sight on a raised rib shotgun.


Once you mill to depth, hand fitting the dovetail for a one off is faster with the file for me.

 

[J-Bar]

This is one of my homemade “safe side” files and the finished product installing a 10/22 folding rear sight on a raised rib shotgun.
View attachment 798744

Once you mill to depth, hand fitting the dovetail for a one off is faster with the file for me.

Stupid question from a non-machinist: how did you remove the file's teeth from one side and keep the whole side straight and flat? I'm thinking a bench grinder would make it look scalloped...

 

[Blue68f100]

I used a large Diamond sharpening stone. Surface grinders work if you have access to one.

 

[jmorris]

Stupid question from a non-machinist: how did you remove the file's teeth from one side and keep the whole side straight and flat? I'm thinking a bench grinder would make it look scalloped...

A belt or disk sander works fine.

 

[Mizar]

Diamond nail files - they are cheap, easy to find and once dulled one just throws them away not worrying that he just ruined a somewhat expensive sharpening stone with that hard steel. Or you can use the coarse Aluminum oxide sharpening stones that cost like $5 and are found in most hardware stores. Use something cheap as you will most definitely ruin it while grinding the teeth off.

 

[jmorris]

The also make a really nice debur knife if you sand all the sides off. You just can't let it get too hot while your going.

 

[troy fairweather]

it relay dont take long with a file t make a dove tail. i made some safe files they work goo yard sale ones are nice to use dont feel as bad when grinding them. i used the tool holder on my dads lathe and put a good stone in the chuck. just go back and forth. i use the angle Gage for the right angles. to help keeping the cut level i use a thin peace of extruded aluminum with a bubble level.