Alignment Jig

[Zonie]

I know most of you know what this is, and what it is used for. I know some of you also have built your own, but for those who need something to do, and enjoy working to Engineering style drawings, I offer you a present. (Hopefully you can read it).
As I am giving it to you, obviously it isn't for sale so Claude and the other moderators shouldn't get too upset.

For those who don't know what it is, this tool is used in conjuction with a drill press by aligning the pointed part with the drill spindle. Once aligned, you bolt it in place to the table.

You then make a small indentation with a center punch at the location where you want the drill to come out (lets say the trigger plate right in front of the trigger).

Center punch the location where you want the drill to go in (lets say on the barrel tang an inch behind the breech).

With the rifle and its trigger plate indentation located on the pointed shaft, move the rifle until the tangs indentation lines up with the drill and proceed to drill thru the tang and about half way thru the stock.
Now, reverse the rifle so the pointed shaft is located in the tang hole and start the drill in the trigger plate indentation, drilling thru the trigger plate and thru the stock to intersect the first hole you drilled.

Like magic, you now have the thru hole in the tang, trigger plate and stock all perfectly aligned.

Oh, this first drilling should be done with the tap drill for the screw, not the clearance hole sized drill.
Zonie

 

[sdakotadoug]

Thanks Zonie, Doug :bow:

 

[Zonie]

Your welcome.

I know you can't really read a lot of the drawing because it is shrunk down but if your interested in actually being able to read all but the really fine text, put your curser on the picture and right click your mouse.
In the pop up window select SAVE PICTURE AS to your computer.
A window will open allowing you to rename the picture and put it into your Photos folder (if you have one).

This is a JPG file so almost any Windows computer should be able to open it for your to look at and print out.

Zonie

 

[Vaino]

Thanks for the dwg....when using this jig to drill for a tang screw that screws into the TP, how is the piece held?......Fred

 

[Zonie]

...how is the piece held?......"

I'm not sure which piece your asking about.

At this stage of the build, the barrel, tang and trigger plate have all been fully inletted.

If the builder has done his/her inletting right, the close fit between the wood and the trigger plate will keep it in place.
I guess if the trigger plate was a really loose fit in the wood there might be a problem with it moving around.
If it moved much, this could cause the drill during the second half of the operation to be mis-located with respect to the other hole thru the tang.
I wouldn't think there would cause a big problem even if this were to happen because basically this set up just stages the rifle and hardware in a position where the holes will be very close to lining up at the correct (compound) angles.

As all of this drilling while using this jig is done using the tap drill size so any minor missalignment between the two holes will disappear when the hole thru the tang and the hole thru the wood are enlarged to become clearance holes.

You don't need to use the jig to do this enlargement for the clearance holes as the larger drill will follow the previously drilled holes and remove the slight missalignment if any exists.

As for what keeps the trigger plate from moving in a loose mortice, if the pointed shaft on the jig is stuck into the center punched mark on the trigger plate, the entire wieght of the rifle will be resting on that point while your positioning the drill to start drilling.
This weight willhold the trigger plate in position.

I hope I understood your question. If not, I'll try again.

 

[Vaino]

My mistake.....the "piece" is the yet unfinished rifle w/ the barrel and trigger plate inletted. What is not clear to me is whether the rifle is balanced on the pointed screw and then the drill centers on the prick punch on the tang or is there a vise or other means to stabilize the rifle during the drilling?.......Fred

 

[paulvallandigham]

Usually the mechanic uses pieces of wood to build up a layer of support for the stock to rest on while the lock is kept on the centers. Shim stock is used anytime you are dealing with a rounded survace.Sometimes you want to enlist the help of three men and a boy to hold the work steady while you do this kind of drilling!

 

[Zonie]

I agree with paul..... (dam that's a lot of letters).

It helps if you can get someone to steady the stock for you while you are aligning the drill point with the centerpunched mark.
I have managed to do this job by myself though but that's because "The Queen" was too busy watching the television. :grin:

 

[paulvallandigham]

Hey, don't complain. The family shortened it! It used to be Vallingdingheimerschmitzenstrudelstrasa y gomez, but the family was embarrassed about that last relative who was reputed to be a wandering survivor of the Spanish Armada, or something like that. ( If you believe any of this, I have a bridge in Brooklen I can let you have cheap!)

 

[Zonie]

Tell you what.
I'll trade my oceanside property in Yuma for your bridge. :grin: