Experimental spindle spider.

[Highpower]

Just testing to see if I can upload attachments properly...

I wanted to put together a spider for the business end of my lathe spindle. I have a 21 inch barrel blank I need to fit and chamber, which poses a problem because the distance between the ends of the jaws on my 4-jaw chuck and my outboard spider screws is 22 inches. :(

I cut down a 6 inch D1-4 back plate and counter-bored the front end to hold a piece of 4" steel pipe with a 1 inch wall thickness. Hopefully that will be enough to prevent any flex in use. Then drilled and tapped for the brass tipped set screws to dial in the bore. I may have to make up some larger brass cups for the set screws though, to get a better purchase on the work. :dodgy:

The new spider reduces the length between them to 19 inches which is good for me. I also won't have to worry about crashing into the massive jaws on that 8" 4-jaw chuck.

At least that's the plan....

   

   

   

   

[EdK]

Willie,

Very nice project, but who in the heck has a piece of 4" pipe with a 1" wall thickness in their scrap box? :huh:

Ed

[Highpower]

Ed,

It depends on what you call a "scrap box".

http://www.speedymetals.com/pc-3588-8242...-tube.aspx

And they didn't even charge me extra for all the mill scale!

[ETC57]

I don't know Ed, but it sounds like a chunk of well casing to me

Jerry.

[EdK]

At $10 per inch, I'd say that's not scrap. ;)

Ed

[DaveH]

Willie,

You made that very nicely - does look good :):):)

Good post and photo's.:)

DaveH

[RobWilson]

Hi Willie

What is "chamber" ? ,,,, excuse my ignorance i have not got a clue when it comes to weapons :huh:


Rob

[Highpower]

Hi Rob,

Basically it is a reaming operation to cut a "chamber" in the end of a barrel that holds the cartridge to be fired. Special reamers are made to provide very specific clearances and match the contours of a particular cartridge/caliber. It is critical that this chamber is perfectly aligned and concentric with the inner bore of the barrel.

   

   

[RobWilson]

Thanks Willie :)

Interesting ,,,, Do you make your own reamers ,,or are they a bought item ?

When you say "specific clearances" is that so the cartridge can slide in and out easy ?

Looks like a machining operation were you could get into trouble easy :(


Rob

[Highpower]

Most folks buy or rent the reamers. Not many people have the machines to make them unless they are in the business of doing so.

The clearances are critical because you could be dealing with pressures of up to 50K - 60K PSI in that chamber. Extreme care is required to be safe.