My Precision Mathews PM1340GT Arrival

I just got my 1340GT up and running. Been busy making parts for my side job.
Outboard spindle spider turned out well. Took a 3" aluminum bar stock, bored out .900" deep to fit snug over the spindle, then bored the rest to 1.5625" to match the inside diameter of the spindle. Cross drilled at 90", threaded 5/16-18 for my hex head cap bolts. I also cross drilled four smaller holes and threaded for some set screws. Turned out shnazzy.
Made a false center for truing bolts. Also turned out well and was my first threading job. I had concerns after reading the dial chart, and since I didn't want to butcher anything, I played it safe and went on "1" each time. Remington bolts are 1/2-13, and I didn't quite understand the whole chart. And, it was a Saturday. Turned out great.
Now all I have to do is figure out the whole posting of pictures here and i am golden.
 
KRW said:
I just got my 1340GT up and running. Been busy making parts for my side job.
Outboard spindle spider turned out well. Took a 3" aluminum bar stock, bored out .900" deep to fit snug over the spindle, then bored the rest to 1.5625" to match the inside diameter of the spindle. Cross drilled at 90", threaded 5/16-18 for my hex head cap bolts. I also cross drilled four smaller holes and threaded for some set screws. Turned out shnazzy.
Made a false center for truing bolts. Also turned out well and was my first threading job. I had concerns after reading the dial chart, and since I didn't want to butcher anything, I played it safe and went on "1" each time. Remington bolts are 1/2-13, and I didn't quite understand the whole chart. And, it was a Saturday. Turned out great.
Now all I have to do is figure out the whole posting of pictures here and i am golden.
Click to expand...

Sounds great. One of these days I will be getting my outboard spindle completed but it is a few notches down on my "to do" list.

Mike.
 
zmotorsports said:
Sounds great. One of these days I will be getting my outboard spindle completed but it is a few notches down on my "to do" list.

Mike.
Click to expand...

I'll probably make mine right after I already need it to support a barrel...:rolleyes:
 
Gentlemen:
My PM-1340GT will be here this week. My WJ200-015SF is sitting there in the box looking at me like a dangerous mountain lion. I wired a new two-story house by myself a few decades ago, but I don't have a clue how this VFD works, especially when you guys are talking about all the different ways to program it. MIKE/MARK, thanks for the schematics. I'll see if I can make something of it. And BILL, I've read enough to know the drill: NO PICS, IT DIDN'T HAPPEN.....so, as soon as it gets here, pics forthcoming. Then, I'll be the little "snot-nosed kid" joining your "big boy club". In other words, I've never turned a lathe on before in my life. Just jet engines. The first ever class I took in machining was a week this summer out to Gordy Gritters place to learn just enough gunsmithing/rifle building to be dangerous to me and others around.

I already have a big question: Gordy (and others) just drilled the "outboard spider" screw holes straight into the spindle, and threaded the four counter-opposing holes for the 5/16x24 socket screws. I have a feeling somebody here is already cringing, but I ordered the tap and drill already to execute that little maneuver. Any advice for that? (planning to use it to chamber barrels through the headstock, of course).

Oh, I also just got my Grizzly G0754 mill/drill this week. Cosmoline, WD-40, cosmoline, WD-40, cos....you all know the idea. I guess I'll start a new thread on that, since I don't see anything on here about that particular model.
I've got a friend about to help me fabricate a stand before I get the mill/drill up and running. More to follow, especially on the lathe......

Lafe
 
RIO said:
Gentlemen:
My PM-1340GT will be here this week. My WJ200-015SF is sitting there in the box looking at me like a dangerous mountain lion. I wired a new two-story house by myself a few decades ago, but I don't have a clue how this VFD works, especially when you guys are talking about all the different ways to program it. MIKE/MARK, thanks for the schematics. I'll see if I can make something of it. And BILL, I've read enough to know the drill: NO PICS, IT DIDN'T HAPPEN.....so, as soon as it gets here, pics forthcoming. Then, I'll be the little "snot-nosed kid" joining your "big boy club". In other words, I've never turned a lathe on before in my life. Just jet engines. The first ever class I took in machining was a week this summer out to Gordy Gritters place to learn just enough gunsmithing/rifle building to be dangerous to me and others around.

I already have a big question: Gordy (and others) just drilled the "outboard spider" screw holes straight into the spindle, and threaded the four counter-opposing holes for the 5/16x24 socket screws. I have a feeling somebody here is already cringing, but I ordered the tap and drill already to execute that little maneuver. Any advice for that? (planning to use it to chamber barrels through the headstock, of course).

Oh, I also just got my Grizzly G0754 mill/drill this week. Cosmoline, WD-40, cosmoline, WD-40, cos....you all know the idea. I guess I'll start a new thread on that, since I don't see anything on here about that particular model.
I've got a friend about to help me fabricate a stand before I get the mill/drill up and running. More to follow, especially on the lathe......

Lafe
Click to expand...

Congratulations of the lathe, I just ordered mine today. Good luck on the wiring too.

I don't think the spindle gets drilled but the collar that makes up the spider. I haven't made one but possibly the spider is held onto the spindle but a set screw? Maybe one of the guy smiths will chime in.
 
sanddan said:
I don't think the spindle gets drilled but the collar that makes up the spider. I haven't made one but possibly the spider is held onto the spindle but a set screw? Maybe one of the guy smiths will chime in.
Click to expand...

That is exactly how I am going to build my outboard spider. I will machine a separate collar that the ID matches the ID of the spindle. The collar will slip onto the outboard of the spindle and be held on with a set screw(or two) and then the four screws will be drilled/tapped into the collar itself.

On some of the Chinese lathes, the end of the spindle is threaded and people merely machine a collar that threads onto their spindle but on the PM1340GT that isn't an option. I saw one guy just make a close tolerance fit onto the spindle, ground a small flat on the spindle for a set screw to tighten down on and it has worked flawlessly for him.

Mike.
 
Drilling the spindle shaft directly is probably not a very good idea unless you leave the belt/gear cover off.

zmotorsports said:
That is exactly how I am going to build my outboard spider. I will machine a separate collar that the ID matches the ID of the spindle. The collar will slip onto the outboard of the spindle and be held on with a set screw(or two) and then the four screws will be drilled/tapped into the collar itself.
Click to expand...

I machined my spider as you outlined. You can purchase 2.5" steel solid rod, or tubing with a 1.5"ID, which decreases the internal boring required, center bored to 1.590" and the step bore to fit over the lathe spindle. Used three or four 5/16-24 x 1/4" NF set screws to lock it on the spindle which was dimpled. Four 3/8-24 x 1 1/4" NF allens for the spider with knurled lock rings. Insert your own bronze or brass tips, or balls for fingers. Make sure the spider holes are drilled at least 1" from the belt/gear cover, otherwise they will hit the cover when extended. If you have a tach that uses magnets, you can embed them in the spider. I have the specifics somewhere, need to check, can post. Spider picture and fingers posted previously .
http://www.hobby-machinist.com/threads/pm1340gt-led-back-splash-light.35509/#post-306677
MetalsDepot.com T2212500 2-1/2 OD x .500 wall x 1.50 ID 1020 DOM A513 Round Steel Tube
Approximate drawing, check on your machine.
Spider.jpg
Lathe Spider Low.jpg
 
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Awesome work MARK. I'm out of my league.
One question: the reason for drilling the spindle itself and installing the spider screws directly into the spindle is to be able to chamber the shortest possible rifle barrel through the headstock (yes, with the cover off - not desirable I know). But, with your over-the-spindle-attachment-spider on the PM-1340GT, what would be the shortest possible barrel you could dial in with at least 1.5 inches or so of the breech sticking out from the 4 jaw? Could you dial in a 20" barrel blank that way?

The other difficulty in drilling/tapping the four holes directly in the spindle, is you'd have to do it by hand with a drill, because it wouldn't be practical to dissassemble the lathe to put the spindle in the mill to drill the holes. I wander if I could do it straight enough by hand? In your case, all you did was dimple the spindle by hand, which is a lot less tedious than drilling through completely into the spindle. Has been done by others though.
 
No experience with guns on the lathe. Very tight clearance to put the spider screws any closer, with the cover on it almost hits the allen set-screws. I drilled the allen screws holes on an indexer to thread, then mounted and dimpled one set screw on the spindle, then tapped that hole, remounted, locked that set screw, then dimpled the other three holes, then removed and threaded those. This way everything lines up, also the angle on the set screws matches the drill angle. So it all locks up very well and true, no wobble. Over the top, but was learning. The current setup, my holes are a little closer to the cover (cannot use cap screws), it is ~15" from the center of the spider screw holes to the front of the spindle face. You would probably need a spider plate mounted to a D1-4 back plate, would be about 17". I had thought of drilling another set of spider holes closer in (1.75" from the outer end, but not into the machine spindle) offset at 45 degree from the outer holes, but then you can't get in with an indicator to center. There are different workarounds that I have seen posted.
http://www.grizzly.com/products/Aluminum-Spider-Plate-5-Diameter/BE1125

This is just one scenario, so each individual needs to tailor to their own needs. If you decide to drill the spindle, take some larger round stock drilled with the holes and fits on the spindle to act as a guide. I wouldn't want to try to do it freehand.
 
Those of you interested in doing barrel or action work should take a look at Bob Pastor's (aka "The Viper") fixture he designed, uses, and sells. He has a couple of videos showing how to chamber a Remington rifle. For very short barrels it may work great too - call him and discuss it with him. 269-251-3671

The man is a world champion 1,000 yard F1 Class shooter so he knows his stuff.... and at the end of the second video he shows a photo of a section of his awards wall... very talented machinist and shooter.


This video is on the fixture itself.

He also has some videos on threading etc...
 
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