Thoughts on a spider

Tincamp67 said:
It’s done. Smooth easy process, but the flaw was indexing off the barrel flats to start the reamer in the guide. Even with the guide, the deeply recessed crown is off center, meaning the bore was off center to begin with. I guess that shouldn’t be a surprise. Range time will tell if it worked. May need to go to the .412 reamer. If I go to .412, I think I’ll chuck up the guide, ream it .412 dead center, and just use the guide with a hand drill this time. Not sure the setup I used last time in the lathe is even necessary?
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I been looking and looking . I know I seen a back boring kit. For the mosin and mausers , it was nothing glamorous. Basically a piloted bore guide and a reamer. The pictures showed hand drill and or moving the table off to the side of floor drill press.
 
The piloted reamer would have helped, but I’m not set up for and have no experience grinding pilots on reamers or drills. Maybe need to teach myself that somewhere down the road. But first, I need to get friends to stop dropping off projects for me to work on so I can clear some of my own stuff.
 
I would love to have a spider for my smithy granite 1324.
Seems pretty straightforward to make. Just remove the locknut from the end of the spindle and replace it with a spider.
On smithys website parts manual, they list the nut as M34x1.5.
My problem is I do not have the gears for my lathe to cut metric threads. So I would have to have someone else make it for me.
 
1.5mm threads are equal to 16.93 tpi. Will any of your gears get close to that? There is always some wiggle room with threads. Or you could buy a spare nut and have a tube welded to the nut.
 
mickri said:
1.5mm threads are equal to 16.93 tpi. Will any of your gears get close to that? There is always some wiggle room with threads. Or you could buy a spare nut and have a tube welded to the nut.
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I had that same thought about buying a spare nut.
Then I ran across this online:
Looks like it would be easier to adapt something to. Maybe turn out a spider and make it a press fit over that nut.

Sadly I do not have a rotary table either to be able to drill 4 holes perfectly 90 degrees apart.
 
JeepsAndGuns said:
Sadly I do not have a rotary table either to be able to drill 4 holes perfectly 90 degrees apart.
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There are multiple ways to get the spacing, plus it doesn't need to be all that precise. Drill & tap 1 in the mill vice using an edge finder both ways. Screw a rod into it and use an adjustable parallel to make that rod level with the vice bed. Repeat. Got a spin indexer? make a quick arbor to hold the nut. Got collet blocks? same as with the spin indexer. Flexible tape measure, wrap it around the part and divide by 4. No mill, drill press.
The Aliexpress nut looks Like an easy fix with a sleeve.
 
You only need to drill two holes. Drill the first hole all the through. Then rotate the tube 90 degrees and drill the second hole all the way through. That's what I did.

My lathe has an indexing feature. If your lathe doesn't then mount the tube in a 4 jaw chuck. Use one of the jaws to scribe a line on the tube. Go to the next jaw and scribe another line. The lines will be 90 degrees apart. Next measure how far in from the end of the tube where you want to holes to be. Mount a sharp tool bit just touching the tube and rotate the chuck to scribe a line that crosses the other lines. Center punch the intersection where the lines cross . Next mount the tube in a drill press or a mill so that one center punch mark centered under the drill. Drill the hole. Repeat for the second hole.
 
Well, I tested an easy theory. No spider, but i turned bushings out of delrin for a snug fit in the spindle bore (outboard side). It’s also a snug slip fit over the octagon barrel (muzzleloader this time). Turned another bushing for the 3 jaw to grab, which tightens the slip fit over the barrel so it doesn’t move. I was able to square off the end of the barrel an cut a slight shallow taper at the muzzle, to aid in ball starting. It’s a trial run for future projects.

Next step, make an aluminum pin to slip in the barrel as a gauge pin, sort of. And use that to see how much run out I’m getting.

BTW, the backboring job on the Marlin cut my groups in half. Now, it shoots 6” groups at 25yds. Not great, but better.
 
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Larry$ said:
There are multiple ways to get the spacing, plus it doesn't need to be all that precise. Drill & tap 1 in the mill vice using an edge finder both ways. Screw a rod into it and use an adjustable parallel to make that rod level with the vice bed. Repeat. Got a spin indexer? make a quick arbor to hold the nut. Got collet blocks? same as with the spin indexer. Flexible tape measure, wrap it around the part and divide by 4. No mill, drill press.
The Aliexpress nut looks Like an easy fix with a sleeve.
Click to expand...

mickri said:
You only need to drill two holes. Drill the first hole all the through. Then rotate the tube 90 degrees and drill the second hole all the way through. That's what I did.

My lathe has an indexing feature. If your lathe doesn't then mount the tube in a 4 jaw chuck. Use one of the jaws to scribe a line on the tube. Go to the next jaw and scribe another line. The lines will be 90 degrees apart. Next measure how far in from the end of the tube where you want to holes to be. Mount a sharp tool bit just touching the tube and rotate the chuck to scribe a line that crosses the other lines. Center punch the intersection where the lines cross . Next mount the tube in a drill press or a mill so that one center punch mark centered under the drill. Drill the hole. Repeat for the second hole.
Click to expand...

Interesting ideas. Seems simple enough.
I sometimes am guilty of over thinking things, when something simple would work.
 
Tincamp67 said:
Well, I tested an easy theory. No spider, but i turned bushings out of delrin for a snug fit in the spindle bore (outboard side). It’s also a snug slip fit over the octagon barrel (muzzleloader this time). Turned another bushing for the 3 jaw to grab, which tightens the slip fit over the barrel so it doesn’t move. I was able to square off the end of the barrel an cut a slight shallow taper at the muzzle, to aid in ball starting. It’s a trial run for future projects.

Next step, make an aluminum pin to slip in the barrel as a gauge pin, sort of. And use that to see how much run out I’m getting.

BTW, the backboring job on the Marlin cut my groups in half. Now, it shoots 6” groups at 25yds. Not great, but better.
Click to expand...

I have done 3 barrels so far on my lathe. Some on here may cringe at how I supported the outboard side of the barrel, but sometimes you have to make due with what you have.
I bought a cheap roll of electrical tape, marked the barrel at the end of the outboard side of the bore, then started wrapping the tape around the barrel until it was a snug fit into the bore.
It actually got it within a few thousandths. Way better than not having any support. Plus, they all were 22lr barrels. 50-100 yards max, so I did not need the same amount of precision that a barrel for a 1000 yard centerfire match rifle would need.
I then indexed the it with the 4 jaw on the chamber end.
I shot one for the first time last weekend for the first time, and it shot great.
 
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