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PM1340 - the Best & Jacobs Full Custom Edition

Alan H

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#31
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!
 

davidpbest

Active Member
Active Member
#32
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
 

Old Squier

Active Member
Active Member
#35
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
 

peder.wennberg

Iron
Registered Member
#36
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!
 

davidpbest

Active Member
Active Member
#37
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.
 

Tozguy

Active User
H-M Supporter-Premium
#38
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
 

firestopper

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#39
Wow David!

Just checked your flicker album, very impressive. Glad to see you used the channel for your stand too.
 

davidpbest

Active Member
Active Member
#40
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.
 

davidpbest

Active Member
Active Member
#41
Wow David!

Just checked your flicker album, very impressive. Glad to see you used the channel for your stand too.
Thanks Paco. I couldn't have done it without your suggestions and encouragement. So thanks. BTW, I just saw your thread on the Rockwell/Delta sander rebuild - super nice job. I love seeing older machine restored to new glory. I also just tripped over the wheeled stand you did for that 3800 pound mill. Wow, I sure wish I could weld like you do. Very impressive. Is that Ironworker part of your shop setup?
 

Tozguy

Active User
H-M Supporter-Premium
#42
David, yes that explains it very well. Great design. Just a couple of ideas: in keeping with the belt and suspenders approach why not add the extra set of three screws to secure the spider to the spindle. Will you be removing the spider very often?
Also, in my case for dialing in rifle barrels, it is very convenient to have the four spider screws lined up with the four jaws at the other end. That way both ends adjust in the same planes. Those knurled lock nuts are on my to do list.

Must say again that you and Mark are an ongoing inspiration, thank you!
Mike
 

firestopper

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#43
Thanks Paco. I couldn't have done it without your suggestions and encouragement. So thanks. BTW, I just saw your thread on the Rockwell/Delta sander rebuild - super nice job. I love seeing older machine restored to new glory. I also just tripped over the wheeled stand you did for that 3800 pound mill. Wow, I sure wish I could weld like you do. Very impressive. Is that Ironworker part of your shop setup?
Thanks David,
Yes the 51 Ton (small) iron worker is part of the shops inventory and is used a bunch. That mill stand is mksj's and was fun to design/ build.
Again, nice work!
 

Kiwi Canuck

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#44
I think I have read this entire post 3 times (or more) and reviewed the images on flickr as well.

I thought I would be able to say something witty or clever but I'm just lost for words, you sir have done an amazing job on that lathe, I'm impressed beyond words can describe.

Thank you for taking the time to post your work and share it here.

David
 

petertha

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#45
Wow, what a beautiful enhancement job. Thanks for taking the time to document with so many pics & vids! I have a 1998 14x40 Taiwan distant uncle to this lathe, so I extracted many useful ideas from your mods & ideas. Couple questions:

- you have a different top-side handle for the carriage lock. I didn't quite get if that was ratcheted or just swings from loose to lock?

- did you modify the stock carriage locking mechanism in any way? (I'm talking about the underside foot or clamp part)

- did you see anything worth upgrading or modifying in terms of the power feed assembly? (ie. the worm gear assembly, the slotted power bar & related mechanism). I suspect my older gen lathe is different with a cast iron C bracket that the power bar loosely threads through. But there are no bushings or contact surfaces to accept thrust load while power feeding or anything to replace with wear. Maybe that's all fixed up with the PM, but I would love to see some pics of your lathe if you happen to have any handy from the rebuild. The PM parts manual PDF wasn't too clear on this & I'm looking for good ideas.

- how about the clutch & ball/spring assembly. Everything ok to your satisfaction or did you do some tweaks to that?


I am considering upgrading from my existing Rong Fu-45 (the original, not a clone) to a PM935. If I do that, I will get the non-variable speed model (never liked mechanical variable speed, plus do not have headroom in my basement for the extra height), and I will work with Mark Jacobs on a control package including VFD (assuming Mark is willing)....

PLEASE DO THIS! Selfish interest - I have an RF-45 as well
 

AirWolf

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#46
WOW.. Really ... WOW.

Thing of Beauty for sure... Wonderful craftsmanship!

This thread needs to be put on the top section - Sticky Threads - for everyone to see
 

woodchucker

Active Member
Active Member
#47
Wow, that's the most tricked out lathe I have seen. Nice job on the cabinets, and little detail things. Nice set of holders and rack..
 

davidpbest

Active Member
Active Member
#48
Well thanks everyone. Much appreciated. This was a fun project and a labor of love. I started off thinking I'd get a 24" bed length version of this 1340, Matt gave me a quote for it, and I was close to pulling the trigger, but everyone here said "longer is better." Who am I to argue with THAT !!?!?!?!

The lathe was not in stock when I ordered it, and came about three months later which was fine. Then it sat in my garage for a few months while I learned to weld, converted a bench to a welding table (https://www.flickr.com/photos/davidpbest/albums/72157672375283855), built a welding cart (https://www.flickr.com/photos/davidpbest/albums/72157671235486470), then tackled the stand construction (https://www.flickr.com/photos/davidpbest/albums/72157672474119185), and then decided to prove I was a REAL MAN capable of moving the lathe into the basement working along (https://www.flickr.com/photos/davidpbest/albums/72157671928399283). And I only lost a single finger in the process (http://www.hobby-machinist.com/thre...-bad-accident-end-mill-defeated-finger.56337/). In all seriousness, the finger loss was not related to any of the lathe work - just a stupid, stupid accident on the milling machine.

- you have a different top-side handle for the carriage lock. I didn't quite get if that was ratcheted or just swings from loose to lock?

- did you modify the stock carriage locking mechanism in any way? (I'm talking about the underside foot or clamp part)
The carriage lock on the stock machine is an M8 socket-head cap screw pulling up on a threaded steel plate that locks against the bottom of the front bed way. Several others here have posted about converting this to some kind of lever locking mechanism, and I decided to do the same. I'm a big fan of Kipp adjustable lever handles, so that's what I employed. If you look at this photo (https://www.flickr.com/photos/davidpbest/32194862321/in/album-72157672547607804/) and the next few, you'll see what I did. I didn't have to make any modification to the clamping plate under the carriage, I just bought a low profile Kipp lever with male 50mm long M8 threaded stud (http://estore.jwwinco.com/default.aspx?page=item detail&itemcode=8N50A32/D), turned a replacement stainless steel handle for it that matched the other handles I made (purely cosmetic), then turned a stainless cover for the body of the lever mechanism (ultra cosmetic).

- did you see anything worth upgrading or modifying in terms of the power feed assembly? (ie. the worm gear assembly, the slotted power bar & related mechanism). I suspect my older gen lathe is different with a cast iron C bracket that the power bar loosely threads through. But there are no bushings or contact surfaces to accept thrust load while power feeding or anything to replace with wear. Maybe that's all fixed up with the PM, but I would love to see some pics of your lathe if you happen to have any handy from the rebuild. The PM parts manual PDF wasn't too clear on this & I'm looking for good ideas.
Well, I definitely discovered some quirks. Probably worth noting here, but Matt at QMT was quick to get things resolved. Here are the quirks - all probably unique to my machine:

The power feed for the carriage is driven through the QC gearbox. Photo:
IMG_5079.jpg

Where that feed drive gear shaft exits the QC gearbox housing, it runs through a bronze bearing pressed into the housing that's lubed from the drip oil system above (just under the switch panel). Photo once shaft and gear train was removed and the bushing cleaned and polished - you can see the oil drip hole in the bushing (fed by a tiny copper tube from above) and spiral grooves to distribute the oil:

IMG_5207.jpg

From the other side:

IMG_5210.jpg

On my machine, the bushing was bound up with what looked like black tar, and was probably paint or filler overspray that got into that mechanism at the factory, heated up and froze the drive shaft. The result was that any kind of power feed would start for a few seconds, then stall as speed increased, and the change/treading gears would grind. In the process of diagnosing the problem, I pretty much stripped/chipped all the the available change gears - the large combo, and the four smaller gears. Once I figured out that the gear shaft coming through the bushing in the housing was the problem, it was about 3 hours work to pull that shaft, get the bushing cleaned out, reassemble the shaft and the gear train on it, get it lubed, and running again. Matt had the factory direct-ship me replacement change (threading) gears which came in a few days and all was fine after that.

If I have any criticism here, it's that the oil for that bronze bushing is fed from a drip point above that's easy to miss. That's what drove me to put in a new single point oil pump and distribution system for the QC gear box. That stock QC gearbox oil drip system is pretty lame IMO, especially when the power feed shaft really depends on lube from above to not over heat and freeze up. Of course, if I were designing this lathe, that shaft would be on a precision permanently lubed titanium bearing. But this is not NASA.

That power feed shaft coming out of the QC gearbox drives a hub clutch with two balls on springs on one side, and a drive plate with dimpled recesses on the other. Drive plate photo:

IMG_5212.jpg

Drive hub with balls and springs:

IMG_5080.jpg


IMG_5081.jpg

It took a while to get that dialed in so the carriage wouldn't start stuttering as the clutch slipped during heavy roughing operation on stainless steel. The ball bearings are tensioned with set screws, so dialing in the clutch tension is not a big deal - just trial and error.

IMG_5083.jpg

The shaft that articulates the forward/reverse switches in the box below the power feed shaft, has a steel paddle secured to the shaft that triggers the two switches. That whole mechanism inside that box is like working on a wristwatch - fussy tolerances, tiny screws (4-40 BTW, not metric), spacers, washers, opposing nuts, etc holding the switches in precise position, etc. If you take it apart, take a bunch of photos first to know how to put it back together.

The cross slide on my lathe came with a really strange distance ring that wasn't just metric, it really belonged on some other kind of machine entirely. The cross slide screw was imperial, worked like you'd expect, but the ring with the mm and inch markings had no correspondence to the distance moved when turning the handle. Again, an email to Matt got this quickly resolved with a direct ship replacement of the threaded shaft, dials and bronze nut - complete assembly - in a couple of days.

Hope this helps.
 

Attachments

sanddan

Active User
H-M Supporter-Premium
#49
Thanks Paco. I couldn't have done it without your suggestions and encouragement. So thanks. BTW, I just saw your thread on the Rockwell/Delta sander rebuild - super nice job. I love seeing older machine restored to new glory. I also just tripped over the wheeled stand you did for that 3800 pound mill. Wow, I sure wish I could weld like you do. Very impressive. Is that Ironworker part of your shop setup?
David,

If you would like to get together some time I can give you some pointers. I've been mig welding for a long time and have it down pretty good. I also have some skills with the tig, though I'm no expert by any means. It helps to get hands on help, seeing through the hood. It would also give me a chance to see that pimped out lathe in person.

Dan
 

Howardd

Iron
Registered Member
#50
Hi David
Mind boggling
Couple of questions
Where did your get the ER40 collet chuck with the D1-4
What size chuck guard did you get?

Howard
 

davidpbest

Active Member
Active Member
#51
Mind boggling
Couple of questions
Where did your get the ER40 collet chuck with the D1-4
What size chuck guard did you get?
What is "mind boggling" about it? Is that a good thing, or a bad thing?

Every photo at the link I initially provided has a description of what's in the photo. Just click on the photo and the text is in a box below the image.

ER40 collet chuck specifics: https://www.flickr.com/photos/davidpbest/33457416614/in/album-72157683014913836/

Flexbar LatheGuard info: https://www.flickr.com/photos/davidpbest/32852017594/in/album-72157683014913836/
 

petertha

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#52
Thanks for your detailed reply & clear pictures.
Sidebar question (sorry I was ogling your tool rack haha). Can you tell me about your knurling tool? Is it your own design or commercial unit? Looks like a standoff integrated to the shank... so you can approach a shoulder & keep the tool post back a bit, or?
 

Attachments

davidpbest

Active Member
Active Member
#53
Thanks for your detailed reply & clear pictures.
Sidebar question (sorry I was ogling your tool rack haha). Can you tell me about your knurling tool? Is it your own design or commercial unit? Looks like a standoff integrated to the shank... so you can approach a shoulder & keep the tool post back a bit, or?
Certainly. I first bought an inexpensive import scissors knurling tool from Enco: https://www.mscdirect.com/product/details/78657012?rItem=78657012

This is not a quality tool, and would have required a lot of tuning, and fixing to make it into one. I didn't have the patience to do this:


So I decided to buy a higher quality knurling tool from Eagle Rock. That's what you see in the photo. Eagle Rock makes lots of different models, right, center, left offset, etc. They're entry level version I'm sure is great, but it's not designed to easily replace the knurling wheels. I bought this one
http://specialtytooling.eaglerockon...-scissor-type-knurling-tools/k1-44-21-0625r-e

from Ajax tools for $300 http://www.ajaxtoolsupply.com/earoknscclkn2.html

I based my decision largely on this review:


The Eagle Rock is made in the USA, and is a fine tool. I wouldn't put it in the category of a Swiss watch or as refined as what Stephan did in his upgrade of an import, but it suits my needs and I can recommend it. That specific tool comes with 20 TPI diamond wheels that are 3/4" diameter, 3/8" wide with a 1/4" bore for the axle.

I had not knurled before jumping immediately into the deep end of the pool, taking on a heavy deep knurling of 316 stainless steel with 12 TPI wheels. These are the wheels:

IMG_5637.jpg

This is what I was making - thumb screws

IMG_5729.jpg

for the sliding cover over the compound DRO scale:

IMG_5738.jpg

That was challenging. And I'd put it at the limit of the 1340 lathe without moving to a solid tool post (eliminating the compound) which I intend to do soon. Jbolt has a thread that discusses the solid tool post mount here on H-M. as well as YouTube videos by Stefan

(
)

and Robin

(
).

The biggest problem I've found with knurling is that under heavy load, the tool post (Dorian in my case) will tend to drift clockwise - which really chowders-up the knurling. Tighten everything down, lock the cross slide, and use cutting oil.

More conventional diamond cutting 20 TPI is much easier on the machine. Here's a video of that operation - making the handles and knobs for the 1340 out of 316 Stainless:
https://www.flickr.com/photos/davidpbest/34162064130/in/album-72157672547607804/ The handles, took several passes at progressively deeper cuts, and it was important to get the OD on the part matched to the TPI of the knurling wheel to get good results.

I ended up making a spreadsheet for looking up the required OD for the TPI knurling wheels I have on hand (12, 20 and 21) and I'm attaching it here - look for the OD you are targeting, and to the right will be the precise OD that comes closest to the target that matches the TPI of the wheel.

Hope this helps.
 

Attachments

Howardd

Iron
Registered Member
#54
What is "mind boggling" about it? Is that a good thing, or a bad thing?

Every photo at the link I initially provided has a description of what's in the photo. Just click on the photo and the text is in a box below the image.

ER40 collet chuck specifics: https://www.flickr.com/photos/davidpbest/33457416614/in/album-72157683014913836/

Flexbar LatheGuard info: https://www.flickr.com/photos/davidpbest/32852017594/in/album-72157683014913836/
In a good way. I can't imagine doing as much as you did in the year or so that you had the lathe.

I was considering the Pratt Burnerd Multi-size collet system but a chuck and set of collets would run about have the cost of the lathe.

Thanks again for all your help
 

jbolt

Active User
H-M Supporter-Premium
#55
+1 on the Eagle Rock K-144. I have the K-201 that uses press pins to hold the knurls and its a pain to change the wheels.