2016 POTD Thread Archive

The big advantage of Tom Lipton's method for cutting metric threads is not having to worry about the lathe coming to a stop when threading to a shoulder. In my case, my minimum spindle speed is 150 rpm which is .4 sec/rev. My reflexes are still fairly good so I can disengage the half nuts in a rev. or less. If I power down the lathe, I have about 3 revs. before it stops.

One trick that I use when threading to a hard shoulder is to loosen the drive belt. There is enough torque transmitted to cut the thread but if I hit the shoulder, the drive will stall and I will not damage the lead screw. I set the carriage stop so the carriage hits just short of contact with the shoulder.
 
That is really nice I need something like that I use a sharped wood screw or a stellite welding rod
 
A few things I wanted to get done for a while. Since I am not a welder, I asked one of my fellow Tucsoan's Paco (Firestoper) to for some assistance. I always drool when I am in his shop, so always a good excuse to check it out when I can. I had some L brackets for my mill casters, they always looked a bit wimpy so Paco put some side braces on the sides. I built a my own drives for my mill, the X has limit switches, but I thought it might be wise to add one to the Z drive. Milled a top block so it acts as a physical stop, but also a limit switch which kicks in just before the hard stop. I removed the Z axis crank assembly and turned a new aluminum plate cover. Power axis drives makes a wold of difference on a mill, I use Bodine AC gearmotor drives with VFDs, all direct drives.

New Brackets for Mill Casters.jpg

Mill Z axis Mecahnical Lift Cover Plate, added Limit Switch and Mechanical Safety Stop.jpg


Since my lathe is in the middle of the garage, there isn't a lot of space for placing messy oil cans and cutting fluid. Paco came to the rescue and welded up a small tray that I attached to the headstock cabinet. It has a raised lip, keeps the lubricants in easy reach but out of the way. Everything got painted and mounted today. Thank you Paco for your help.

Lathe Oil Can Tray.jpg
 
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RJSakowski said:
The big advantage of Tom Lipton's method for cutting metric threads is not having to worry about the lathe coming to a stop when threading to a shoulder. In my case, my minimum spindle speed is 150 rpm which is .4 sec/rev. My reflexes are still fairly good so I can disengage the half nuts in a rev. or less. If I power down the lathe, I have about 3 revs. before it stops.

One trick that I use when threading to a hard shoulder is to loosen the drive belt. There is enough torque transmitted to cut the thread but if I hit the shoulder, the drive will stall and I will not damage the lead screw. I set the carriage stop so the carriage hits just short of contact with the shoulder.
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I use the brake pedal on my lathe to get the head to stop quickly. Hit the pedal, then turn off the motor. Release pedal, reverse to the beginning and do another pass. Works for when you can't release the half-nut (like when you do metric threads on an imperial lead-screw lathe)...
 
dave_r_1 said:
I use the brake pedal on my lathe to get the head to stop quickly. Hit the pedal, then turn off the motor. Release pedal, reverse to the beginning and do another pass. Works for when you can't release the half-nut (like when you do metric threads on an imperial lead-screw lathe)...
Click to expand...

That's my plan for when I finally get my Harrison M300 spinnin'. With my lathe the brake automatically drops out motor power which is a safety plus.
 
intjonmiller said:
You can reverse the feed safely. It's quite simple. But Tom Lipton has a video on it that explains it far better than I could. Find his video on metric threading with an inch leadscrew.

Edit - here it is:
Click to expand...

I bet Tom Lipton would love to have a carriage stop proximity sensor set up like the one's Mark (mksj) builds. The process Tom posted is a cool trick nonetheless.
Thanks for sharing Jon.

mksj said:
A few things I wanted to get done for a while. Since I am not a welder, I asked one of my fellow Tucsoan's Paco (Firestoper) to for some assistance. I always drool when I am in his shop, so always a good excuse to check it out when I can. I had some L brackets for my mill casters, they always looked a bit wimpy so Paco put some side braces on the sides. I built a my own drives for my mill, the X has limit switches, but I thought it might be wise to add one to the Z drive. Milled a top block so it acts as a physical stop, but also a limit switch which kicks in just before the hard stop. I removed the Z axis crank assembly and turned a new aluminum plate cover. Power axis drives makes a wold of difference on a mill, I use Bodine AC gearmotor drives with VFDs, all direct drives.

View attachment 131710

View attachment 131711


Since my lathe is in the middle of the garage, there isn't a lot of space for placing messy oil cans and cutting fluid. Paco came to the rescue and welded up a small tray that I attached to the headstock cabinet. It has a raised lip, keeps the lubricants in easy reach but out of the way. Everything got painted and mounted today. Thank you Paco for your help.

View attachment 131712
Click to expand...
Your very welcome Mark. Glad those worked out for you. Its always a pleasure to help out a friend and fellow member that contributes so much to this forum, and continues to teach me things.
Your generosity is appreciated by many.

Paco
 
mksj said:
A few things I wanted to get done for a while. Since I am not a welder, I asked one of my fellow Tucsoan's Paco (Firestoper) to for some assistance. I always drool when I am in his shop, so always a good excuse to check it out when I can. I had some L brackets for my mill casters, they always looked a bit wimpy so Paco put some side braces on the sides. I built a my own drives for my mill, the X has limit switches, but I thought it might be wise to add one to the Z drive. Milled a top block so it acts as a physical stop, but also a limit switch which kicks in just before the hard stop. I removed the Z axis crank assembly and turned a new aluminum plate cover. Power axis drives makes a wold of difference on a mill, I use Bodine AC gearmotor drives with VFDs, all direct drives.

View attachment 131710

View attachment 131711


Since my lathe is in the middle of the garage, there isn't a lot of space for placing messy oil cans and cutting fluid. Paco came to the rescue and welded up a small tray that I attached to the headstock cabinet. It has a raised lip, keeps the lubricants in easy reach but out of the way. Everything got painted and mounted today. Thank you Paco for your help.

View attachment 131712
Click to expand...

Those turned out great Mark, and I am sure they are of the highest quality seeing as how that is all Paco does.

I have to admit Mark after seeing pictures of your lathe a while back, I started machining new knobs for my PM1340GT last night. I had a job lined up for the weekend but when I got home from work last night I had a message that the guy cancelled. I already had some swarf on the lathe because of the previous night's work so I figured I may as well knock out the new knobs. Last night I was able to get the two for the gearbox on the headstock completed. Between tonight and tomorrow morning I should be able to complete the remaining knobs on the lathe and get rid of the cheap ass plastic ones that look horrible.

Mike.
 
Every 6 to 9 months a client orders another set of these mini doors with full-size hardware. :)

Image1467381598.587599.jpg

I just need to mortise the latch plate (5/8" router bit with guide bearing) and then this half is done. The other piece is a simple square base of thinner stock. Very simple construction, and a good way to get a couple hundred bucks now and then. They are retail counter displays for showing off their electronic keypad deadbolts. I wished they had waited a couple more weeks and then I could have done all the drilling on the mill/drill. Instead I had to do this on my little drill press and just get it done so I can get back to the task of making room for the mill. It's driving me nuts to not have it yet. But there are worse things than having paid work to do.
 
I posted in a Facebook group (tools, equipment, and machines for sale locally) a few weeks ago that I was looking for a machinist's level to use for an afternoon when I get the mill in my shop, and to help better dial in the lathe. My brother of all people commented, "I think I have one." I was REALLY skeptical, as this is the guy who gave me the machines that don't have any tooling to speak of, and he never learned to really use them. He's a master automotive technician, so it's really not his kind of tool.

Sure enough he had one. Apparently it came with the mill when he got it from our father. Not as long or quite as precise as I had hoped to find, but WAY better than my contractor levels.

Image1467390886.302871.jpg

Apparently Lufkin stopped producing precision tools in the 1960s, but this appears to be in immaculate condition, other than *very* light surface rust on the bottom. That should come off with little more than a paper towel. I'll spend some time making sure it's calibrated before putting it to use.

I love free tools. :)
 
I had a Starrett that size when I retired, I sold some of my tools, that's the one I really regret selling.
 
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