Budget Lathe chip shield

[Ashlyn Katarzyna]

These are my plans!

Drawing only, its too late to start cutting tonite.  I'll update it in the next day or so.

My $6 chip shield broke last week not bad because it lasted for 2 years, basically it was a piece of plexiglass that I heated and curved 90 degrees, which was secured to the lathe bench with spring clamps and a hook to hold it down along with a piece of cardboard and another clamp.

I devised a plan to make my own shield on a budget.  I am very confident that it will work as drawn out.  I bought a 4 jaw chuck for my lathe so I can secure the rectangular steel block in and bore and counterbore it for the proper bearing support. 

Could support the front of the pivot with a bushing but I don't think it will be an issue because I don't plan on .0005 tolerance maybe a few thou. 

The hardest part will be dimpling in the proper location and drilling on center, maybe need to use the mill for stability. 

Keep in mind this is the shield and pivot mount, not the base and attaching mount, you have to provide that mock up yourself because mini through larger hobby lathes are set up different.  I might provide a non-destructive mount for my shield because the Logan is fully restored and original except the paint.


What is 660 SAE Bronze like when it gets turned?  Does it work harden like Aluminum Bronze does and will turn powdery when it gets cut - similar to cast iron? 

Opted for steel, that way if I mess up I can fill it with weld and start over.

[Ashlyn Katarzyna]

I've had a medical emergency that I need to tend to, probably will be out for awhile.

[spuddevans]

Nice looking plans there 

I've had a medical emergency that I need to tend to, probably will be out for awhile.

You just take all the time you need, your health is far more important than machining. I hope everything works out ok for you.


Tim

[Ashlyn Katarzyna]

Well health wise things seem to be on track, CT scan came back good I dont know why it did but its probably that stupid Celiac disease acting up again. Anyways, a few pictures of the processes. I have the first ball detent tacked on, I didn't want to make it too redneck so i did dress up many of the parts prior to welding or press fitting.  Color will probably be baked on HT Enamel Silver like the lathe is.

I had to use bronze aluminum bushings for the shaft, I couldn't justify buying sintered bronze from the hardware store $6 each and I still had to machine them and a 1.5" bar of bronze aluminum was out of my reach I did have 1 bushing I made on a production run that was perfect and I was able to keep a few slugs and go from there.   

The shaft is made from an old bench grinder that burned up, I pushed the comm off the shaft and turned it down smooth enough for it function.

I also included grooves for retaining rings to keep the shaft locked in place, over all the design is solid and it locks in place in the full up position.  A few design changes took place during the initial build. 

To secure the mechanism to the lathe in a non-destructive manner I will purchase a pair magnetic tool makers block with 250+lbs of pull and turn them on to keep the shield in place. This will be dual purpose as I can use the blocks for milling operations as well, but this will add to the budget of the chip shield by about $72, but I can remove them for cleaning or I can modify/add to the finished product. http://www.shars.com/products/view/1395/5quot_x_2quot_x_2quot_Magnetic_Toolmaker_Block_and_Chuck

My initial intent was a budget build, I tend to over build projects by about 200% so many of the things I build will never break under normal or extreme use.

This is the backing plate I chose for the mount to the base it is not pictured to have a hole in it yet but I burned up 1 drill and a boring bar on the lathe before I tossed it on the mill for a 1.5" dia hole. The steel is bearing steel so it ate the M2 tool steel up in about 3 minutes.


You can't even tell the chuck is moving at 800rpm I guarantee it is even though you can see the model numbers on the  jaws .

Turning the pipe down, it actually is 12" x .750 pipe. I cut the threaded sections off but it could have easily been kept on the ends and use caps with a retainer to hold the shaft in place-intensely complicated and over done-when you see the final the product it is amazingly simple the way I made it.

[Brass_Machine]

Well health wise things seem to be on track, CT scan came back good I dont know why it did but its probably that stupid Celiac disease acting up again.

I missed this thread. I am very glad to hear that things will be OK for you. Health things are always frightening.

Back to your thread. It looks like you are off to a good start. Will watch this.

Eric

[MadNick]

Morning!

Im glad that your health is on track and am following the thread with interest.

I have had some perspex knocking around here for a while which needs to be put to a good use

All th best.

Nick

[Ashlyn Katarzyna]

Tack welds for now.

Anyways, I have done a bunch of tinkering with design and the ball detent didn't work as planned, the main problem is weight on the bar that hangs off one side- We'll call it plenty of leverage (some scientific name for that). 

I had to cut the welds off and weld up the 3/8" holes and start over. I started by asking my Dad for advice and he suggested cutting into the shaft in such a profile that a stop was drilled half way through the diameter on the shaft, for this I chose to drill a new 1/4" hole and sand it out with the dremel so that I could rotate the shaft to unlock the shield. I would use an exhaust valve for a hardened locking pin, I tried the square end for unlocking/locking that worked for the lockup, but to unlock all it would cause was binding, a rounded nose was required.

When I say hard I mean really hard as in dulls HSS cutoff blade per partoff. 

The Pin




Spring was cut 1 coil at a time until I had the desired amount of pressure for my pin, basically the spring holds pressure on the pin while it is in the hole drilled in the shaft. Without a spring there is nothing to keep the pin locked and thus it could and would unlock during lathe operation which would cause the shield to fall on a rotating chuck.

In the one photo you will see the spring is up and the next it is down that is the lock up.


I considered making a manual unlock that I could reach around the back of the lathe for, but during setup that would be a PITA and I'd be altering it again in 1 week.

You wont see the 8x10 Lexan glass in any pictures, I have not done any work with the setup other than building the frame work for the glass. I don't really want it scratched so it stays off for now.   I purchased a roll of Felt and some heavy rubber sheeting for the lathe bed, felt for wipers and rubber for chip/dust control on the ways, I use a heavy cotton comforter for a lathe cover it was free.

Thumbnails for now, click to enlarge.


This last photo is the mockup I will use for gaining access to the rear retaining ring so if needed this can be disassembled for whatever reason and reverse is as easy as take down.

[markball2]

This installs over the chuck?

Like this?

[Ashlyn Katarzyna]

Finally it is done.  The base is stand alone, add some weight it wont go anywhere, $$$ is tight now so I'll drill and tap the ends and mount it to the lathe cabinet.

[jcs0001]

ChadA4MG  - interesting project.  I also noticed your chuck key holder - neat idea.

John.

[Ashlyn Katarzyna]

ChadA4MG  - interesting project.  I also noticed your chuck key holder - neat idea.

John.

If you make holder like that add something to mount so it doesn't rotate down, I use an S hook hoop that I cut and tacked in.
Harbor freight wrenches are good for something, one was already cracked I just helped it break, I broke the other one taking a T3 Turbo apart.