PM1340 - the Best & Jacobs Full Custom Edition

David,
Thanks for sharing all this. Your 1340 is a piece of art to say the least.

It is very kind of you to put the drawings out there as well. I plan on doing something similar to my machine for oiling the quick change gears. So that drawing will be very helpful.

I am hoping you get that 935 soon so we can all see what you do to it!
 
Hi Alan, thanks for your kind words. It was my pleasure to share the drawings as I have scalped so many others here in the group for ideas. BTW, there's an error in one of the drawings. Can you find it? LOL

David
 
Great job David!

Just found this, lots to see in those pictures.
 
Wow! What a beautiful job. I'm hoping to accomplish just a fraction of the great mods you have done here before the end of the year. I'm especially loving your stand. Excellent, truly!

Squire

Sent Using Tapatalk - Cherokee Nation of Oklahoma, Tahlequah OK
 
David,

After all the work, is the lathe stand as stable as you expected? Also, can you provide the dimensions of the stock chip tray that came with the lathe? I'm going to build a version of your stand but will use the stock tray and I can't find any dimensional info. on it. Again, fantastic work!
 
David,

After all the work, is the lathe stand as stable as you expected? Also, can you provide the dimensions of the stock chip tray that came with the lathe? I'm going to build a version of your stand but will use the stock tray and I can't find any dimensional info. on it. Again, fantastic work!


Thanks. Yes, the stand is plenty stable and rigid - no issues there so long as you put in the gussets and bracing as shown on the plan and center position leveling feet. The stock chip pan is approximately 69 x 18 inches, the drain for the coolant is just left of center, right under the bedway casting - absolutely in the wrong place if you want to mount the pan to a flat surface like the c-channel mounting I used. It might work if you built a 1/4" thick rectangle tube ladder structure to bolt the lathe to that had recesses where the pan drain tube could stick down, or if you wanted holes through the lathe mounting platform to make the chip pan removable below the lathe mounting. But the stock chip pan has a 12mm diameter tube sticking down about 2 inches, and a dimple in the sheet metal to collect coolant - wrongly placed to make the chip pan removable IMO. I tried, frustratingly, to cut out that tube and dimple and then TIG weld in a flat patch in that area and gave up. $125 to have a new super rigid aluminum one fabricated and welded up was a no brainer for me.
 
David, I hope that we are not overdoing the question period and keeping you from using that beauty but the outboard spider shown in the picture of the tach pickup has me intrigued. How is the spider fitted to the spindle and are those thumb screws for locking the screws (that are not shown)? Thanks, Mike

IMG_5421.jpg
 
Wow David!

Just checked your flicker album, very impressive. Glad to see you used the channel for your stand too.
 
Hi Mike, I'm happy to answer questions and clarify things. Just glad someone is interested enough to ask.

This was my first turning on the lathe once I got it running. I remember feeling like I was running by the seat of my pants, basically trying to copy what some others have done and posted about here. Nothing was aligned and I had pretty crude cutting tools at that time, so the finish quality was pretty so so.

The spider I turned from a 3-inch long piece of 1018 steel tubing, 2-1/2" in diameter with 1/2" wall thickness. This is what I started with.

IMG_5423.jpg


After facing off one end, I bored out the ID to give a close fit to the section of spindle sticking out the left side of the headstock. I don't remember now the precise dimension, but I ended up about 0.001 to 0.002" oversized on the ID. I bored just deep enough to create a flat shoulder to rest against the end of the spindle - giving it a registration seat against the spindle end. Looks like this:

IMG_5303.jpg


It ended up with a nice slip fit. I then turned down the OD just enough to provide clearance with the hole in the gear cover casting that mounts over the change gears and pulley/belt drive, then turned the part around, mounted it on the lathe in a 4-jaw chuck, centered it and faced off and cleaned up the ID and OD from the opposite end.

To secure the spider sleeve to the spindle, I drilled and tapped for M6 brass tipped set screws 120 degrees apart on the mill, then did another row also 120 degrees apart but clocked 60-degrees out of phase with the first set, and about 1/2" further out on the spider. I wasn't sure if 3 set screws were enough, or if I'd need an outboard set to keep it aligned both radially and axially - as you can see, I'm paranoid and inclined to belt and suspenders wherever possible. I also machined out pockets for the cylindrical magnets for the Hall Effect sensor on the MachTach at that end. Here's a photo that shows that detail, but I never installed the second set of three set screws - didn't need them:

IMG_6366 (1).jpg


At the outboard end of the spider sleeve, I decided to employ 4 screws 90-degrees apart to dial in whatever part the spider was keeping aligned. I figured four screws would be easier to adjust the part to centerline than three (and I was right). I first milled a flat spot about 5/8" diameter then drilled and tapped for 1/4-28 alignment screws. The screws shown are brass tipped steel (McMaster 91381A359) and I used Stainless Steel Knurled-Head Thumb Nuts (McMaster 91833A107) to secure the adjustment screws. This is how the adjustment screws look from the end.

IMG_5426 (1).jpg


I have a second set of longer screws for smaller diameter work with longer reach. I made those from socket-head cap screws, drilled the ends to receive tiny brass rod inserts secured with Loctite.

And finally, I used a 10ths indicator to mount the spider and align it radially and axially so it has no wobble and doesn't create any shimmy or weird vibrations at high speed.

Hope this helps.
 
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