Restoration/Repairs on a 10" LD Utilathe - Standard Modern
- Thread starter Brent H
- Start date
Brent H
Ultra Member
So I am away from the lathe for a while but I have been still making things....
I can't try out the new quill for the tail stock just yet but I am working on a new half nut. The older model LD type Utilathes actually have a half a thread that engages the threading screw. The Thread screw is a 7/8 - 8 TPI Left Hand ACME. Given that the root diameter is just over 3/4" it makes using a larger boring bar and tool bit possible. This greatly increased the rigidity in the threading process and my threads came out with very little chatter.
I used a piece of cast iron for the half nut. The Cast iron I chose is listed as impact resistant and able to take repeated stress without failure
I can't try out the new quill for the tail stock just yet but I am working on a new half nut. The older model LD type Utilathes actually have a half a thread that engages the threading screw. The Thread screw is a 7/8 - 8 TPI Left Hand ACME. Given that the root diameter is just over 3/4" it makes using a larger boring bar and tool bit possible. This greatly increased the rigidity in the threading process and my threads came out with very little chatter.
I used a piece of cast iron for the half nut. The Cast iron I chose is listed as impact resistant and able to take repeated stress without failure
- Yield Strength: 55,000 psi
- Hardness: Rockwell C20 (Hard)
Brent H
Ultra Member
While I am waiting to get home to my shop I am working on the plans for a taper attachment.
I believe the one for the 9" Utilathe will fit/be the same as the one for the 10 and 12" LD models and as I am scaling the drawing it seems to be in the ball park.
Here is a screen shot of what I have so far:
My son measured the distance on the back of my lathe to allow for 27" where the attachment could fit. There is a set of double screws on the back I think are for something else so I scaled the picture to be 24 inches long (the blue line in the imbedded image) and then went from there. I am hoping perhaps YYCHobbyMachinist can lend me a hand with a few measurements
I believe the one for the 9" Utilathe will fit/be the same as the one for the 10 and 12" LD models and as I am scaling the drawing it seems to be in the ball park.
Here is a screen shot of what I have so far:
My son measured the distance on the back of my lathe to allow for 27" where the attachment could fit. There is a set of double screws on the back I think are for something else so I scaled the picture to be 24 inches long (the blue line in the imbedded image) and then went from there. I am hoping perhaps YYCHobbyMachinist can lend me a hand with a few measurements
Brent H
Ultra Member
Long time between updates on the project that is really close to completion:
YYC and I combined forces with Chicken Lights to provide me with most of the taper attachment I needed and I will show some parts machined when I get back home to do so.
My new half nut fit the threads on the lead screw perfect and after machining in the guide groove and the eccentric slot everything fit perfect. There is no way to engage partially off the thread dial lines as the lathe tended to do from time to time.
I line bored the tail stock again and finally took off the ovality that was showing at the back end of the stock. This was great but left my new spindle 0.010 under size - crap - so I will be making a 3rd tail stock spindle.....alas ...the process.......
YYC and I combined forces with Chicken Lights to provide me with most of the taper attachment I needed and I will show some parts machined when I get back home to do so.
My new half nut fit the threads on the lead screw perfect and after machining in the guide groove and the eccentric slot everything fit perfect. There is no way to engage partially off the thread dial lines as the lathe tended to do from time to time.
I line bored the tail stock again and finally took off the ovality that was showing at the back end of the stock. This was great but left my new spindle 0.010 under size - crap - so I will be making a 3rd tail stock spindle.....alas ...the process.......
Brent H
Ultra Member
Tailstock spindle in the process of getting redone. This morning I machined down a slice of 4140 2” round stock to my 10 thou required oversize from my last effort.
The final pass I was running 2000 RPM at a 0.005” per Rev feed rate and spray cooling the tool bit. Solid carbide coated insert. Depth of cut was only 0.015 final pass to remove 0.030” off the diameter.
I guess it would be best to turn between centres for accuracy but we have things dialled in quite well and there is less than 0.0002” discrepancy over the 7” of shaft. Next stage is to cut off the end and 4 jaw chuck it for machining in the #2 morse taper. That will be all I can do until I get home to my bigger mill and can do the fancy oil relief and slot for the key. I was also able to hack off a chunk of cast iron from a damaged engine block to make a follower for the new (to me) taper attachment .
Sorry the pictures are sideways. Seem to do that when reducing size - ugh
The final pass I was running 2000 RPM at a 0.005” per Rev feed rate and spray cooling the tool bit. Solid carbide coated insert. Depth of cut was only 0.015 final pass to remove 0.030” off the diameter.
I guess it would be best to turn between centres for accuracy but we have things dialled in quite well and there is less than 0.0002” discrepancy over the 7” of shaft. Next stage is to cut off the end and 4 jaw chuck it for machining in the #2 morse taper. That will be all I can do until I get home to my bigger mill and can do the fancy oil relief and slot for the key. I was also able to hack off a chunk of cast iron from a damaged engine block to make a follower for the new (to me) taper attachment .
Sorry the pictures are sideways. Seem to do that when reducing size - ugh
Looking good. What is the OD of the spindle shaft? I guess we will see your next step pics but just wondering out loud if it will extend inside the headstock spindle ID or if you will require steady rest?
On the 'better accuracy between centers' thing, I've always wondered about this. For sure one needs between centers turning if you have to flip the part end for end or otherwise return it into position. Or machining right up to the end of the stock vs. parting off. But if its just doing the OD operation, does it make any difference if its HS chuck>TS center vs. HS center>TS center? The chuck is gripping, its rotating... what else can a center do to improve accuracy on the HS end?
On the 'better accuracy between centers' thing, I've always wondered about this. For sure one needs between centers turning if you have to flip the part end for end or otherwise return it into position. Or machining right up to the end of the stock vs. parting off. But if its just doing the OD operation, does it make any difference if its HS chuck>TS center vs. HS center>TS center? The chuck is gripping, its rotating... what else can a center do to improve accuracy on the HS end?
Brent H
Ultra Member
Hi Peter,
The final OD is 1.6025"
What I did to help accuracy is to machine a 3" stick out section round, flip the shaft so the round 3" section was chucked, face and drill a center in the shaft and then put everything in order and machined the shaft. The shaft is still quite thick so no steady required. I will slice off the larger end with our chop saw and then face the shaft to proper length, bore the centre out after it gets zero'd in the 4 jaw and then set up to cut in the Morse taper. Once I taper the spindle I will chuck in a #2 Morse taper reamer and finish the taper hole. After that I will try out a few taper drills with some bluing to check for a good fit.
One thing I am thinking is to cut the side slots in the shaft to allow you to wedge out a tanged drill or centre as well as some of the centres that have no tang. My tail stock works on the principal that when you retract the shaft all the way the screw bangs into the back of the inserted tool and knocks it free. This works great for tang fitted bits but not so great for some centres that do not have that wee extension.
I think the only thing that will affect the accuracy at the head stock is if your three jaw has run out - like the back plate is off a bit or when you chuck something your head stock is not right on alignment with the bed. We had some issues with this until we tore off the back of the lathe to access the bolts and set the head stock running totally parallel with the ways. On my Utilathe I had to shim one side to get the head stock in line. Now I can turn a stick out piece of steel to within a couple tenths over 8"
The final OD is 1.6025"
What I did to help accuracy is to machine a 3" stick out section round, flip the shaft so the round 3" section was chucked, face and drill a center in the shaft and then put everything in order and machined the shaft. The shaft is still quite thick so no steady required. I will slice off the larger end with our chop saw and then face the shaft to proper length, bore the centre out after it gets zero'd in the 4 jaw and then set up to cut in the Morse taper. Once I taper the spindle I will chuck in a #2 Morse taper reamer and finish the taper hole. After that I will try out a few taper drills with some bluing to check for a good fit.
One thing I am thinking is to cut the side slots in the shaft to allow you to wedge out a tanged drill or centre as well as some of the centres that have no tang. My tail stock works on the principal that when you retract the shaft all the way the screw bangs into the back of the inserted tool and knocks it free. This works great for tang fitted bits but not so great for some centres that do not have that wee extension.
I think the only thing that will affect the accuracy at the head stock is if your three jaw has run out - like the back plate is off a bit or when you chuck something your head stock is not right on alignment with the bed. We had some issues with this until we tore off the back of the lathe to access the bolts and set the head stock running totally parallel with the ways. On my Utilathe I had to shim one side to get the head stock in line. Now I can turn a stick out piece of steel to within a couple tenths over 8"
Ah, thanks for clarifying.
A hole in the barrel to drift out MT tools might be a good idea. So good it makes me wonder why this isn't a standard feature, maybe I'm missing something. I hate it when my tool shank is stuck. Supposedly when stuck, you are supposed to just crank the handle to eject it, simple as that. There is tremendous mechanical advantage on leadscrew so I get nervous when it still wont come out. I've confirmed it is bottoming, no issue there. And it has nothing to do with the tang. My lathe TS doesnt retain on the tang.
So when it happens, I sigh, end up removing the handle & spindle so I can tap out the tool with a rod from behind. This is a PITA & just seems wrong. You are not supposed to use anti-seize or much of any kind of lubrication on the shank, otherwise MT shank spins in the socket. I change the tools often so its not like the oil is getting sticky or adhesive or anything. I've asked about this on other forums & the 'answer' seems to be give the TS handle a slight whack to eject it (=more mechanical advantage on the lead screw). I worry about buggering the handle axle or worse yet the brass lead screw nut. A cross-wise drift hole in the spindle seems so logical. Maybe my socket is just sticky for some reason. I try hard not to allow any grit in there changing tools. I've blued it & it is a nice a fit as I could hope for. If anything, slight variations in tooling shank manufacturing should make ejecting easier. I have one drill chuck that likes to stick. Unfortunately its very precise so is my favorite.
A hole in the barrel to drift out MT tools might be a good idea. So good it makes me wonder why this isn't a standard feature, maybe I'm missing something. I hate it when my tool shank is stuck. Supposedly when stuck, you are supposed to just crank the handle to eject it, simple as that. There is tremendous mechanical advantage on leadscrew so I get nervous when it still wont come out. I've confirmed it is bottoming, no issue there. And it has nothing to do with the tang. My lathe TS doesnt retain on the tang.
So when it happens, I sigh, end up removing the handle & spindle so I can tap out the tool with a rod from behind. This is a PITA & just seems wrong. You are not supposed to use anti-seize or much of any kind of lubrication on the shank, otherwise MT shank spins in the socket. I change the tools often so its not like the oil is getting sticky or adhesive or anything. I've asked about this on other forums & the 'answer' seems to be give the TS handle a slight whack to eject it (=more mechanical advantage on the lead screw). I worry about buggering the handle axle or worse yet the brass lead screw nut. A cross-wise drift hole in the spindle seems so logical. Maybe my socket is just sticky for some reason. I try hard not to allow any grit in there changing tools. I've blued it & it is a nice a fit as I could hope for. If anything, slight variations in tooling shank manufacturing should make ejecting easier. I have one drill chuck that likes to stick. Unfortunately its very precise so is my favorite.
Brent H
Ultra Member
Hey Peter,
Here is the table for the slot location and dimensions required. One thing I have with my lathe is that the key slot in the tail stock spindle is at the 90 degree location where the slot would also be.
I have a #2 MT so the wedge slot needs to be 0.260" (dimension w) - argh! but I think I can mill that and then make a new piece for the spindle lock (again) that is .260 wide. The taper knock out would then slip out the key way in that location - would be fine as it would be opposite to where you would tap.
My lathe also does not use the tang to keep the tools from rotating, just the fit and - just like you, my good center seems to be just that much too short and I do not wish to weld on a bump. The older one I have can be unscrewed with a pin wrench and then you can, I guess, Screw in a tang. The tang for our smaller tail stocks eats up a bit of drill length as it can be bumped out when you retract the bit and the tang hits the screw.
perhaps the measurements above will help you out.
Another challenge I will have is to index the spindle - should be fun!
Brent H
Ultra Member
Success!!!
Fit the new tailstock spindle today and it all works perfect. No slop at all and looks great. I milled a new 1/4” slot in the spindle I made (again) about 0.010” bigger to better fit the tailstock.
I milled a slot right through as per the morse taper info given in the machinist handbook for a #2 taper. I then fit the spindle in the tailstock and set up to find the top - I used this nifty level gauge/scribe so that once the pointer is at zero you can then Either use the scribe to leave a mark or I made a line :
Everything fits great. Next is to etch on graduations - will see how that goes later on. Busy times before Christmas.
Fit the new tailstock spindle today and it all works perfect. No slop at all and looks great. I milled a new 1/4” slot in the spindle I made (again) about 0.010” bigger to better fit the tailstock.
I milled a slot right through as per the morse taper info given in the machinist handbook for a #2 taper. I then fit the spindle in the tailstock and set up to find the top - I used this nifty level gauge/scribe so that once the pointer is at zero you can then Either use the scribe to leave a mark or I made a line :
Everything fits great. Next is to etch on graduations - will see how that goes later on. Busy times before Christmas.
Brent H
Ultra Member
Finally, having a couple hours to finish things off:
Checking to make sure cut line is parallel. Used a slitting saw to cut off the sections.
The new compound extension for the 10” Utilathe compared to the smaller one for the 9” Utilathe.
next is to work on the sliding block and the assembly will be good to go!
departing for work on Christmas morning so Merry Christmas everyone!!
Checking to make sure cut line is parallel. Used a slitting saw to cut off the sections.
The new compound extension for the 10” Utilathe compared to the smaller one for the 9” Utilathe.
next is to work on the sliding block and the assembly will be good to go!
departing for work on Christmas morning so Merry Christmas everyone!!
Brent H
Ultra Member
I have re-written the manual -per say of the 10 inch Utilathe after digging all over the internet.
I redid the drawings and set out the type so it is all legible. It is just under 4 MB in PDF. Is there a way to up load it for sharing? I get a "file to large error" don't think I can reduce it any further?
I am hoping in the future to add more scaled drawings so folks could make their own missing follow rest or steady etc
I redid the drawings and set out the type so it is all legible. It is just under 4 MB in PDF. Is there a way to up load it for sharing? I get a "file to large error" don't think I can reduce it any further?
I am hoping in the future to add more scaled drawings so folks could make their own missing follow rest or steady etc
