2019 POTD Thread Archive

[NCjeeper]

I got some rotary table action in today. Making a lamp shade spider for my wife so she can use it in the stained glass shade she is making.

 

[mattthemuppet2]

got a bit more done on my Dad's penknife

made a jig, drill ALOT of holes and have mostly worked out the cam and spring. Still need to move the pivot a little closer to the spring as it doesn't have a very positive action and has a bit of slop when opened. Some more holes to drill

 

[ddickey]

Facemill holder/arbor that registers on the quill face. Hopefully to increase rigidity. Turning for the 3/4" shank and trepanning the relief was done on the lathe and all other operations were done on the mill for maximum concentricity. Got the idea from youTube channel Solid Rock Machine Shop.

 

[NCjeeper]

It came out pretty good. I would hate to have to make a bunch of these. Definitely a job for a CNC mill.

 

[dave_r_1]

Continued on with my power broom project (from here https://www.hobby-machinist.com/thr...you-make-in-your-shop-today.67833/post-648318)
Well, it took a lot longer than I planned to make the lifting mechanism, there was a lot of thinking, then fabbing, then doh, cutting bits off, and more thinking and more fabbing, and finally late tonight, I got about 80% done [I can lift/lower the broom using a handle, but it's not bent to be more convenient to use from the operators position, it needs proper limit posts for the range it's supposed to have, and I need to figure out how to make another handle (or put an electric actuator somewhere else), as now the lifting handle interferes with one of the caster wheels when the broom is lowered. Sorry no pics, as I did a short test of the broom in my garage, and that gave me a wicked headache from the carbon monoxide...

From that test though, turns out the belts I bought are the right length, broom seems to have no belt slippage and decent power behind it when lowered.

And I need to add some weight to the rear of the drive unit, as, in particular with the broom raised, the drive wheels didn't have a lot of traction.

It's done enough that I hope to test it out tomorrow, as we are supposed to get about 1/2 to 1 inch of snow.

 

[SamI]

I finally got round to (semi) finishing this part to restore a Hardinge lever operated collet closer I bought a while back with the intention of modifying it to fit my lathe. The original part was pretty badly worn and as I found out was also cracked in a few places (partly my fault as I has to grip it so tightly in the chuck in an attempt to remove a seized on bearing retaining nut). Anyway, rather than risk working with a cracked component on the lathe I decided to re-make.

Made from D2 tool steel. I've still to broach the internal keyway before it goes into the furnace for heat treatment. I've not made anything quite as large as this but the last parts I made were tested to 55 HRC. I think I'll try either an oil quench or blasting it with compressed air to see if that improves things at all.

The part was almost 100% perfect to drawing until I made a schoolboy error on the threads! I measured across wires but took the wrong dimension from my scribbles so accidentally turned the pitch diameter to the root diameter! Not to worry though, I was machining the bearing retaining nut to match anyway. Just would have been nice to have it spot on. I'll know it's wrong!



And here it is with said nut installed. A little chatter in these threads - think I'll have to invest in a larger internal threading tool! Just need to drill a couple of holes in this for a pin spanner and it should be good to go. Toying with the idea of installing a grub screw to stop it backing off but part of me is thinking some loctite would be the better option so as not to marr the threads (exactly what caused such an issue getting the old one off!).




All threading done in reverse at 400 RPM. I am absolutely in love with threading this way! I have threaded at 700 RPM in alu using this method which is great because I simply don't have the patience to wait for the thread to turn at 70 RPM if I'm heading up to a shoulder!

 

[mattthemuppet2]

Toying with the idea of installing a grub screw to stop it backing off but part of me is thinking some loctite would be the better option so as not to marr the threads (exactly what caused such an issue getting the old one off!).

one option is to fold up a piece of solder and drop that down the hole, then screw in your grub screw. The first time you tighten the screw it will force the solder to conform to the threads, so it will grip them but not mar them. I've done this a bunch of times and it works really well.

 

[jdedmon91]

I recently made a MT3 center drill holder. I had a couple center drills that was made to be used in Face & Center machines. Because of the flats these drills will not work in a drill chuck. I was lazy and just drilled the hole, so the center drills would wiggle when center drilling. So to fix my goof up I bored the holder out and bushed it out. Here is the video

Sent from my iPhone using Tapatalk

 

[tjb]

Built A Fixture To Index The Spindle On The Lathe

View attachment 289549

View attachment 289550

Owners of old Logans know how small the dials on the cross feed are and how hard they are to read. I plan on making
a set of bigger dials, but to do that I need to index the spindle to inscribe the marks. So I built a fixture.

First, an old but unworn 100 tooth gear was sourced on eBay. In order to securely lock the gear I need a solid mounting
point for the fixture. By removing the lathe's reverse gear assembly, I was able use it's mounting hole and the bolts that secure it
to the headstock. A 6061 spindle with an offset flange was turned and cross drilled for a 1/4 inch steel pin. The end of the pin
was ground to fit between the teeth on the gear, and a set screw provided to secure it. A spacer was turned and pressed
into the gear to adapt it to the aft end of the spindle, and a brass plug with an MT3 taper was turned to fit into the opposite
end. All those parts are held together with a length of all thread acting as a drawbar. My 4 jaw chuck can
be mounted right over the top of this stuff, and I was pleased to find that the gear locks up solidly when it's all in place.
Loosening the set screw is all it takes to move the gear to the next tooth. Now all I have to do is make the part!

Would love to see follow-up posts with pix using the fixture to make the dials.

Regards,
Terry

 

[BGHansen]

POTD was replacing the rubber tires on my 12" Craftsman wood band saw. I bought the saw around 35 years ago and had been milking the stretched out tires by Gorilla gluing them to the aluminum wheels. Time for a proper repair . . .

Bought a pair of urethane tires from www.polybelt.com for around $30 delivered. Installation is pretty easy though I'm glad it's not how I make my living. The instructions recommend heating the tires to 120 F to make them more stretchy. Good call, especially when my shop was a balmy 25 F at the time.

Pulled the wheels, clamped them to a bench and pulled really hard to stretch the new tires in place. The new tires should last through my lifetime.

Bruce


Didn't pull them at opposite ends for the photo to show how much the
original rubber tires had stretched, but they were about 1 1/2" longer than
the urethane replacements.


Clamped the bottom wheel to the workbench with the tire staged in place.
The kit includes a screwdriver to work the tire over the wheel, but I just went
with brute force and stretched the tire in place with my finger tips.


Top wheel wasn't coming off the upper axle, so pulled the whole mounting
assembly.


New tires in place. Runs nice and smooth, should have done this years ago.