Vent Liner installation info request

[cjensen]

I have a 2/3 scale 1841 from Dixie Gunworks/AKA Hern with a .240" vent hole drilled.
What would be the best way to install a vent liner?

[Victor3]

 I can't find it, but somewhere there's a post that shows a cutaway drawing of one installed. Maybe one of the other guys here knows what post that is (?)

 On one of my cannons, I made a liner from a 1/2-13 stainless bolt with a .125" hole drilled through the center for the vent hole. The threaded end of the bolt had a cone turned on the end to match the angle of the drill point in the liner. When tightened, the angles mated to seal off gas similar to some hydraulic fittings.

[Double D]

Victor you are right....I have that picture.





And now that you mention it, I have dimensions of an original, they are in the front of one of the plan sets I have from AOP.  Vent hole is .200. But I can't read the rest on the numbers. 

For my Golf ball mortar I have been using 3/8-16 socket head cap screw.  I have a holding fixture for the screw and put it in my three jaw chuck and drill a #16 hole.  I use a #16 drill because I don't have  4.5 mm drill. #16 is .177 and 4.5 mm is .1772.  Whats the difference!   This hole lets me use the paper straw quill which are 4mm.

[cjensen]

Really good information. Thanks so much.
Fortunately I am the forth owner and the barrel has yet to be fired.
Of course this brings up some more informed questions.
1/4X20 hole tapped with a #16 hole, should this work?
Where do I get some copper for this?
Does stainless work as well as copper? Stainless is available and free.
How many rounds before the vent is shot and needs replacement? (How many do I need?)

I plan on using 4 mm paper straws, does any place sell these at less than the $40 price I am am finding?

1# 4F GOEX, 19# GOEX Cannon and 5# 1F GOEX is in the mail.
Worm is in hand.
White Oak is in the works.
Stump remover and cotton rope is in hand.

Is there a safe way to use 2F for blank charges if I reduce the charge, I have 25# of 2F?

Wheels, I am leaning towards the small hub 2" wide wheels form this place.
http://www.customwagonwheels.com/cannon-wheels.html
I know the large hubs will look better and be more accurate, but the price difference is enormous.
Is there a reason the small hubs will not WORK?

[Double D]

1/4X20 hole tapped with a #16 hole, should this work?

No. To small.  Use 3/8 16.

Where do I get some copper for this?  Does stainless work as well as copper? Stainless is available and free.
How many rounds before the vent is shot and needs replacement? (How many do I need?)

Use the stainless and be sure and put high temp anti seize on the threads

I plan on using 4 mm paper straws, does any place sell these at less than the $40 price I am am finding?

Nope not that I recall any one saying...don't worry about it,  this is a one time cost!!!

 
 

Stump remover and cotton rope is in hand.

Make sure your stump remover is potassium nitrate and the cotton rope is 100% cotton and no synthetic core

Those are what I know.  Those who know the other stuff will have to give their opinions.

[GGaskill]

Make sure you make allowance for the minor thread diameter versus the vent diameter.  Evil Dog and I went through a really irritating process milling out a broken bolt with a broken drill in it because the bolt was too small for the hole.

A 1/4-20 bolt has a minor diameter of about .200" so a .125" hole through that gives you a pretty fragile piece.

[Terry C.]

Depth is also critical. You'll want to dimple the liner so that the vent will seat against it. But be careful not to go too deep and break through.

Can you tell how thick the liner is?

[cjensen]

Depth is also critical. You'll want to dimple the liner so that the vent will seat against it. But be careful not to go too deep and break through.

Can you tell how thick the liner is?

I"ll be doing some serious cipherin before I drill and tap

[Terry C.]

Cipherin'?

Make sure you wear your iron hat.