Case Hardening the Permanent Spindle #lathe


Brandon Nugent
 

Question for larger group:

Should the headstock spindle be case hardened?  Or even just slightly hardened?  

Today I 'finished' machining the headstock spindle and am wondering if it shouldn't be hardened in some way to protect it from regular use.


Ethan Allred
 

I would say no. It shouldn't need hardening. If you want to protect it go with an enamel or epoxy paint.


On Wed, May 12, 2021, 14:16 Brandon Nugent <nugentmakes@...> wrote:

Question for larger group:

Should the headstock spindle be case hardened?  Or even just slightly hardened?  

Today I 'finished' machining the headstock spindle and am wondering if it shouldn't be hardened in some way to protect it from regular use.


Bill in OKC too
 

I don't think it needs to be hardened. If you just want to, that would be up to you. Be aware that hardening it will cause it to warp. Then you'd need to grind it. You essentially open several cans of worms that you don't need opened. 

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)


A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)





On Wednesday, May 12, 2021, 03:16:18 PM CDT, Brandon Nugent <nugentmakes@...> wrote:


Question for larger group:

Should the headstock spindle be case hardened?  Or even just slightly hardened?  

Today I 'finished' machining the headstock spindle and am wondering if it shouldn't be hardened in some way to protect it from regular use.


Brandon Nugent
 

Thanks Ethan, Thanks Bill.

I am moving forward and if the spindle gets mangled from harder materials, I will clean it up and re-evaluate the need for hardening.


Bill in OKC too
 

The spindle should not ever get mangled from hard materials. You'll likely use a center in it, or a chuck or faceplate on it, and the material should never actually touch the spindle. 

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)


A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)





On Wednesday, May 12, 2021, 06:25:19 PM CDT, Brandon Nugent <nugentmakes@...> wrote:


Thanks Ethan, Thanks Bill.

I am moving forward and if the spindle gets mangled from harder materials, I will clean it up and re-evaluate the need for hardening.


Drag
 

What material did you use to make the spindle out of in the first place? What work are you planning to do with the spindle, and is that it shown in the picture? Do you intend to use something like  three/four jaw chuck with it in the future?
My apologies but it has been quite end some time since I read the Gingery books so I may be missing a step somewhere...

Drag


Ethan Allred
 

I'm pretty sure all of the cast parts are aluminium.


Brandon Nugent
 

The spindle is 1018 mild steel.  And yes that is shown in the picture on the left.  Currently I only have a faceplate and plan on building the Gingery 4 jaw and other accessories.  It's all between center turning at the moment so the work is turned with a clamp dog holding the work and pinned between the centers.  I had noticed some deformation on the temporary headstock spindle, mostly cosmetic, but it had made me wonder whether some time in the forge and an oil quench might be in order.

So far so good.  Today I turned out a tool I needed for another project using the setup and it seemed fine.  No issues.


Ethan Allred
 

I honestly misread the question and thought you had mentioned the headstock, not the spindle. 

I'd say it would be worthwhile if you wanted to case harden the end of the spindle with the center. Until you have a chuck/face plate you'll be wearing against it with every setup, and 1018 will get a lot of damage from dogs/etc.

Just make sure to temper it afterwards if you go that route.


Brandon Nugent
 

Not a problem!  Thanks for the updated feedback.


Bill in OKC too
 

The spindle is not likely to be a cast part. IIRC, it is supposed be drill rod or cold-rolled steel. If  you make it of drill rod, you can heat and quench it, but that can warp it. If  you're using cold-rolled steel, and for some reason want it hard, you'd have to heat it and apply the case hardening compound and then quench. Again, likely warping it. With the drill rod it should be hardened through, while the CRS will have a hard surface layer, but be soft inside. 

Went and looked, the spindle is supposed to be 5/8" CRS. 

Bill in OKC 

William R. Meyers, MSgt, USAF(Ret.)


A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)





On Thursday, May 13, 2021, 06:07:50 PM CDT, Ethan Allred <cavemaneca@...> wrote:


I'm pretty sure all of the cast parts are aluminium.


Guy Winton
 

You could bore the spindle you have and insert a hardened, ground center

-Guy-


On May 13, 2021 at 8:21 PM Brandon Nugent <nugentmakes@...> wrote:

The spindle is 1018 mild steel.  And yes that is shown in the picture on the left.  Currently I only have a faceplate and plan on building the Gingery 4 jaw and other accessories.  It's all between center turning at the moment so the work is turned with a clamp dog holding the work and pinned between the centers.  I had noticed some deformation on the temporary headstock spindle, mostly cosmetic, but it had made me wonder whether some time in the forge and an oil quench might be in order.

So far so good.  Today I turned out a tool I needed for another project using the setup and it seemed fine.  No issues.


 


Brandon Nugent
 

I like that idea! 

Future spindles are in the works.  One of which will have a threaded section to hold screw on chucks or other holding devices.   Another will have a complete bore all the way through.


Nelson Collar
 

Brandon
Your shaft will get damaged every time you crank a grub screw into it. One way I have found to take care of that problem is cut a nice flat on the shaft, then place a piece of brass in the cut out with superglue. Turn the shaft down to true the brass to proper size of shaft. If the brass gets too chewed up apply some heat to it and replace the brass with a fresh piece. 
Good luck, set or grub screws have always left nasty marks but there is and answer to everything.
Nelson

On Thursday, May 13, 2021, 08:21:32 PM EDT, Brandon Nugent <nugentmakes@...> wrote:


The spindle is 1018 mild steel.  And yes that is shown in the picture on the left.  Currently I only have a faceplate and plan on building the Gingery 4 jaw and other accessories.  It's all between center turning at the moment so the work is turned with a clamp dog holding the work and pinned between the centers.  I had noticed some deformation on the temporary headstock spindle, mostly cosmetic, but it had made me wonder whether some time in the forge and an oil quench might be in order.

So far so good.  Today I turned out a tool I needed for another project using the setup and it seemed fine.  No issues.


Brandon Nugent
 

Ah that's a good idea thanks!  Going to try this one out.


dgortonii@...
 

That's an excellent feature to include where grub screws are utilized. To take it one small step forward, my old ShopSmith uses that design on their spindle, which runs all of the tools for it's multi-function design. They not only include a flat on the spindle, but the put an angle into to, sloping down and away from the end of the spindle.  This makes any forces trying to pull the tool off the spindle have to overcome not only the friction of the grub screw, but also the angle of the flat acting as a wedge against the grub screw.