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9" SM Utilathe Restoration
- Thread starter YYCHM
- Start date
As you say, more complex = more time. But generally if you can sketch the pertinent views & dimensions, I can work from that. To use proper cad terminology, what I build is the the 3D model. Its a rendition of the physical part. Then 'drawings' are generated from that, those contain the different views, dimensions, sections.... basically what the fabricator needs to make the thing. The drawings can be PDF files so easily email-able. Or with a mouse click, of the format that the water jet / laser cut shops require.
Dabbler
ersatz engineer
Ive put my toe in the water for CAD - I keep getting hung up on the mindset needed to do it in the first place. I always want to start with the dimensions, as that is closer to how I think (detailed oriented, etc)...
I have yet to figure out a good 'mind set' to approach CAD, and the tutorials always are for the worng version, so it is totally distracted from learning the process, just o figure out the menus!
I have yet to figure out a good 'mind set' to approach CAD, and the tutorials always are for the worng version, so it is totally distracted from learning the process, just o figure out the menus!
historicalarms
Ultra Member
MeeeTooo!!
I think the most important thing for CAD usage is an above average computer skill l& understanding...something I never acquired. I owned 2 cad programs, one was a rudimentary "cheap" offering that I thought would be 'easy to learn but it wasn't...and then my I.T. SIL pirated a Auto-cad "PRO" download & a manual 4 inches thick to go with it...they both soon became forgotten icons on a computer screen.
Brent H
Ultra Member
ACAD - sadly the program is way to complex for just simple things - its easy to draw simple things in it, just not as well suited to a basic circle square line triangle type thing.
I have no use for the 3D modelling - perhaps I can see things in the matrix without it
- but 2D works fine for me. It could go back to drafting in high school....
I was lucky to be one of those kids that was ground floor computing - learning to program in Basic, Fortran, Pascal etc and AutoCad was version 6 at the time. I think the best version of AutoCad for me was the 2006 version that allowed you to first start dropping pictures in and scaling from that. Then they got all greedy and wanted subscriptions etc
Our machine shop just got their first CNC plasma table - I can send AutoCAD drawings over and they can produce parts - pretty cool! As for the actual machining CNC - not sure I will ever do any of that - ya never know, but I lack the patience to sit at a desk programming all day and then watch a tool smash itself to bits and wreck a piece because I missed a step.
For farting around and learning CAD there is NanoCad for free out there and it seems to work well. If PeterT can draw it out, however - very nice!
@Dabbler mentions starting with Dimensions - That is pretty much how I use the Auto Cad for laying things out and drafting the parts - Start with a line, draw another at 90* and then off set the lines to the dimensions I want something to be ......perhaps a good set up at the start John and then just use that template for your drawings and you would find it easier. Seems to be the way with the programs - takes hours to get the first set up and then you are good to go....Just need to survive the first stage........
I have no use for the 3D modelling - perhaps I can see things in the matrix without it
- but 2D works fine for me. It could go back to drafting in high school....I was lucky to be one of those kids that was ground floor computing - learning to program in Basic, Fortran, Pascal etc and AutoCad was version 6 at the time. I think the best version of AutoCad for me was the 2006 version that allowed you to first start dropping pictures in and scaling from that. Then they got all greedy and wanted subscriptions etc
Our machine shop just got their first CNC plasma table - I can send AutoCAD drawings over and they can produce parts - pretty cool! As for the actual machining CNC - not sure I will ever do any of that - ya never know, but I lack the patience to sit at a desk programming all day and then watch a tool smash itself to bits and wreck a piece because I missed a step.
For farting around and learning CAD there is NanoCad for free out there and it seems to work well. If PeterT can draw it out, however - very nice!
@Dabbler mentions starting with Dimensions - That is pretty much how I use the Auto Cad for laying things out and drafting the parts - Start with a line, draw another at 90* and then off set the lines to the dimensions I want something to be ......perhaps a good set up at the start John and then just use that template for your drawings and you would find it easier. Seems to be the way with the programs - takes hours to get the first set up and then you are good to go....Just need to survive the first stage........
Gee thanks Brent, now I remember why I gave up on these things.... I decided to try your nanoCAD. It's better than
QCAD or LibreCAD, this only took me three hours to figure out, but I'm thinking I would be hard pressed to reproduce it. Maybe another 3 hours to figure out how to change the dimension scaling.
Today my drill chuck refused to eject from the tail stock.
All this managed to do was spin the chuck's JT33 taper. She's stuck in there real good.
This had no effect what so ever.
Hmmm..... I ain't got nothing small enough and long enough give it a boot from behind.
Finally this worked. It's my spare cross slide screw which just happens to be the same thread as the tail stock. Interesting that it didn't take much to pop her out with this method. That's a 6" long crescent wrench.
The damage. A scored MT2 taper and messed up spindle nose.
Not sure why this is happening to me? Maybe the BB chuck and taper are junk? The tail stock spindle should be aligned with the headstock spindle now.
All this managed to do was spin the chuck's JT33 taper. She's stuck in there real good.
This had no effect what so ever.
Hmmm..... I ain't got nothing small enough and long enough give it a boot from behind.
Finally this worked. It's my spare cross slide screw which just happens to be the same thread as the tail stock. Interesting that it didn't take much to pop her out with this method. That's a 6" long crescent wrench.
The damage. A scored MT2 taper and messed up spindle nose.
Not sure why this is happening to me? Maybe the BB chuck and taper are junk? The tail stock spindle should be aligned with the headstock spindle now.
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Glad you got it off. It happens on my lathe occasionally. If a hard free spin turn of the TS wheel doesn't work to self release, then I remove the wheel & just put any old metal rod & tap axially from behind. Its just hitting the end of the tang. One time I also warmed the quill with a heat gun a bit but not sure it did much. I'd be a bit apprehensive of hitting the chuck from behind like that just because there has to be a little side component force that is then transferring into you chuck/arbor assembly & your TS assembly including the fit of your quill barrel. Actually screw jacking in like that is a perfect solution.
I don't have a good answer on why. Minor debris, higher axial force from heavy drilling or either of the arbor or mating quill socket are scratched are the usual reasons given. I have good surfaces on both but I now know if I install it bone dry or its been in there for a while, it has a higher chance of sticking. Supposedly the taper angle is self releasing but all it takes is a bit of sandpaper action & those surfaces can mate up hard as you experienced. I now use the tiniest amount of thin lubricant & seems like that is the happy medium. It wont free spin like a fully lubricated oiled surface, but it helps a lot with sticking. So like a spritz of WD40 or thinner (which contains a bit of light oil) on a clean paper towel & basically all wiped off. I now avoid using the handy rag to clean the arbor & hole because inevitably it could be a bit oily and have chips on it. If there wasn't any grit on the surfaces before, you probably stand a good chance of putting some on by wiping with a not clean rag.
To my mind, an off-spec arbor should theoretically release easier than a perfect one. If the taper is shallower or steeper, it has less contact area along he length. Same deal if it was slightly not circular. But obviously something is happening, so maybe its not that simple. Maybe bad fit means micro annular gap and that could maybe distort a bit & jam in tighter? Or the gap is a tiny place for grit to become lodged? I came close to lapping mine but resisted the urge. I think you would have to have a very 'known' precision lap or sacrificial arbor, otherwise probably stand a good chance of making the socket worse, nevermind cleaning out the compound & all that fuss.
I don't have a good answer on why. Minor debris, higher axial force from heavy drilling or either of the arbor or mating quill socket are scratched are the usual reasons given. I have good surfaces on both but I now know if I install it bone dry or its been in there for a while, it has a higher chance of sticking. Supposedly the taper angle is self releasing but all it takes is a bit of sandpaper action & those surfaces can mate up hard as you experienced. I now use the tiniest amount of thin lubricant & seems like that is the happy medium. It wont free spin like a fully lubricated oiled surface, but it helps a lot with sticking. So like a spritz of WD40 or thinner (which contains a bit of light oil) on a clean paper towel & basically all wiped off. I now avoid using the handy rag to clean the arbor & hole because inevitably it could be a bit oily and have chips on it. If there wasn't any grit on the surfaces before, you probably stand a good chance of putting some on by wiping with a not clean rag.
To my mind, an off-spec arbor should theoretically release easier than a perfect one. If the taper is shallower or steeper, it has less contact area along he length. Same deal if it was slightly not circular. But obviously something is happening, so maybe its not that simple. Maybe bad fit means micro annular gap and that could maybe distort a bit & jam in tighter? Or the gap is a tiny place for grit to become lodged? I came close to lapping mine but resisted the urge. I think you would have to have a very 'known' precision lap or sacrificial arbor, otherwise probably stand a good chance of making the socket worse, nevermind cleaning out the compound & all that fuss.
Don't think so. It would appear that it spun a little and galled at the spindle nose. The taper has a score where it meets the spindle nose and the inside of the spindle nose has a narrow shallow section that's messed up.
What the symptom of the tang jamming?
A few turns of the MT2 reamer and an hours worth of emery work appears to have cleaned up the spindle bore.
Here I'm attempting to cleanup the chuck taper. Been working at it with emery for over an hour now.
That chuck has a visible wobble in this configuration? I wonder if I should replace the whole thing?
Here I'm attempting to cleanup the chuck taper. Been working at it with emery for over an hour now.
That chuck has a visible wobble in this configuration? I wonder if I should replace the whole thing?
Ok, I did some measuring. What's coming out of the chuck jaws is aligned with the taper. It's the chuck sleeve that's wobbling around.
Further playing around revealed that the chuck taper may have been sitting proud in the tail stock spindle. After cleaning things up (including running the MT2 reamer into the spindle) the taper now sits a good 3-4mm deeper in the spindle and the tail stock screw ejects the taper with plenty of room to spare. I'm thinking the taper was hung up on the mouth of the spindle and not seating fully. The location of the damage to the spindle and taper would suggest that as well.
Will see what happens now.
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That’s good news. Your chuck is in working order. Good job on finding the culprit (not sitting far enough in the spindle) and getting the ejector to work for you.
I have had taper arbors that were a little short (not the tang type) for consistent ejection. So I made a special bolt for the back of it to “lengthen” it to make sure it comes out without trouble.
I have had taper arbors that were a little short (not the tang type) for consistent ejection. So I made a special bolt for the back of it to “lengthen” it to make sure it comes out without trouble.
As in drilled and taped them? All my centers (2 live and 2 dead) are stubby (ie no tang) and don't eject via the TS screw. How does one hold a taper in a lathe chuck so that it can be drilled and tapped?
no, the arbor came with a tapped hole in the back (It can accept a drawbar). Some people make / buy screw-in tangs. I just made a special, low profile headed bolt.
Have you seen these at Madmodders?
https://madmodder.net/index.php/topic,13067.0.html
https://madmodder.net/index.php/topic,13067.0.html