07-22-2012, 11:00 PM
I have posted this project on other sites, but I would like to share it here and maybe glean some more ideas as I build it. Hopefully it will give others some ideas too.
I decided to start on the dividing head I've been planning to make for years. I saved two Deutz diesel engine pistons WAY back when for this project. They are good solid aluminum chunks with a precision hole and a precision steel wrist pin in that hole. The wrist pins are bored through with a precision hole too, so in my eyes, these were instant headstock and tailstock for a dividing setup. Well, not exactly instant...
I managed to find them in the junk in the shop and set up one on the mill table and decked off the top with a fly cutter. Tomorrow I'll do the other one and see if I can find a proper gear to use for the 'divider' and dream up a stop for that. I think I'm going to buy a Harbor Freight wood lathe 4 jaw chuck. It appears to be perfect for this. It is 6" in diameter and mounts on a 3/4"x10 thread. That means a standard bolt can become the headshaft for this thing. I'll make a taper for the tailstock and copy a design for the adjustment from Gingery's book on the dividing head.
Oh, the plan is to run them 'upside down', that is with the top becoming the bottom. That makes the distance from the table greater for clearance.
Here are the pistons before starting and one of them cut. This is one of the first projects for my new Grizzly G0705 mill.
and here is the chuck I'm thinking about, it is actually a wood lathe chuck from Harbor Freight.
I remembered I have a 4" rotary table I have never used. So, making a base with a step on it will put the centerline of the rotary table the same height as the centerline of the center of the wrist pin in the piston. Hooah, I like it when things work out well. I have some 1/2" aluminum plate so I'll cut a base for mounting both the rotary table and the headstock on. That will allow me to clamp the base to the mill table with the rotary table hanging out over the end if necessary for long stock cuts. A similar but smaller base on the tailstock will work well.
Also, the bore of the wrist pin is .704, so a 3/4" bolt will be perfect. I can turn down the shank of it for a nice slip fit through the wrist pin and machine a flat on the end to fit into the slot in the rotary table. Good stuff!
Here's the table and headstock.
and the headstock piston.
I think I will be able to squeeze about 22" between centers, and a 16" plus carbine barrel will be a piece of cake.
So, here's a simple drawing of how the thing should go together.
That's all I have done so far.
I decided to start on the dividing head I've been planning to make for years. I saved two Deutz diesel engine pistons WAY back when for this project. They are good solid aluminum chunks with a precision hole and a precision steel wrist pin in that hole. The wrist pins are bored through with a precision hole too, so in my eyes, these were instant headstock and tailstock for a dividing setup. Well, not exactly instant...
I managed to find them in the junk in the shop and set up one on the mill table and decked off the top with a fly cutter. Tomorrow I'll do the other one and see if I can find a proper gear to use for the 'divider' and dream up a stop for that. I think I'm going to buy a Harbor Freight wood lathe 4 jaw chuck. It appears to be perfect for this. It is 6" in diameter and mounts on a 3/4"x10 thread. That means a standard bolt can become the headshaft for this thing. I'll make a taper for the tailstock and copy a design for the adjustment from Gingery's book on the dividing head.
Oh, the plan is to run them 'upside down', that is with the top becoming the bottom. That makes the distance from the table greater for clearance.
Here are the pistons before starting and one of them cut. This is one of the first projects for my new Grizzly G0705 mill.
and here is the chuck I'm thinking about, it is actually a wood lathe chuck from Harbor Freight.
I remembered I have a 4" rotary table I have never used. So, making a base with a step on it will put the centerline of the rotary table the same height as the centerline of the center of the wrist pin in the piston. Hooah, I like it when things work out well. I have some 1/2" aluminum plate so I'll cut a base for mounting both the rotary table and the headstock on. That will allow me to clamp the base to the mill table with the rotary table hanging out over the end if necessary for long stock cuts. A similar but smaller base on the tailstock will work well.
Also, the bore of the wrist pin is .704, so a 3/4" bolt will be perfect. I can turn down the shank of it for a nice slip fit through the wrist pin and machine a flat on the end to fit into the slot in the rotary table. Good stuff!
Here's the table and headstock.
and the headstock piston.
I think I will be able to squeeze about 22" between centers, and a 16" plus carbine barrel will be a piece of cake.
So, here's a simple drawing of how the thing should go together.
That's all I have done so far.
Ken
An old tired/retired/wanna-be machinist.
An old tired/retired/wanna-be machinist.