2017 POTD Thread Archive

[BGHansen]

I'm guessing that there was some draft angle on the stem of the knob. True?

Did you use an adhesive to attach your bushing?

Great fix. I hope the pipes in the wall hold up. You gotta stop feeding that kid so well.

Yes, little bit of draft for pulling the boss from the mold. I measured the boss diameter at the top and bottom, knew the depth and trig'd it out to something like a 1.75 deg. angle on one side. I didn't show it, but set the compound up with angle gauge blocks to the lead edge of the cross slide instead of the protractor on the compound. I used a drop of urethane Gorilla glue to hold it in place.

Bruce

 

[4GSR]

I am a little curious just why the radius on the right side of the cutter? My understanding of Acme is they all have the same angles cut then the point adjusted to the Number of pitch cutting. Curious!

That radius is from the grinding wheel. I just ground down far enough to clear the bore of the thread. Some inserts are ground so they "top" the OD or ID of the thread with a pre-determine edge radius. But not in my case.

 

[woodchucker]

Well, a bit of metal working, but more work with the paint brush and wire grinder - to do all the prep work. Decided to display my miniature locomotive in the annual local hobby railroad train show. This required new livery, as it had been laid up for years in a sad neglected state due to the advanced age of the prior owner. Figured I needed a deadline to ever get ‘er done so to speak.

Here’s some before and after pics.

Glenn

Stunning difference. Beautiful. Nice work Glen.

 

[extropic]

Yes, little bit of draft for pulling the boss from the mold. I measured the boss diameter at the top and bottom, knew the depth and trig'd it out to something like a 1.75 deg. angle on one side. I didn't show it, but set the compound up with angle gauge blocks to the lead edge of the cross slide instead of the protractor on the compound. I used a drop of urethane Gorilla glue to hold it in place.

Bruce

BINGO!

Those are the little details that make the big difference, IMO. Thanks for posting.

 

[Firestopper]

POTD was a press tool for removing/installing a 4" x1.5" bushing.
I used .750" CR flat bar that was left over from the finger extensions I've been working on and some 2" CR round I had in the scrap pile.

The clamp link works with the pivot block and is adjusted for different material thickness to be bent on a finger brake. Both bushings where worn well beyond specifications. The two bushings (new) where made from one 4"x 5".
A piece of .750 flat bar was laid out and cut on the bandsaw.

I stayed close to the line, the thicker 2 O'clock area is the factory edge after cutting the profile.
I used a sharpie, then scribed the line to help my old eyes. Don't care for Dykem too much for little jobs. Its like PVC primer and ends up all over my hands, face, etc. hehe.

Punched out the center with a 7/8" annular cutter.

Chucked up a 2" round bar and turned it down for a snug fit

Ran a single TIG pass at 200 Amps and let it cool completely before chucking on the lathe.
Turned the OD .150" smaller than the bushing OD and the step was kept .001" under the ID of the bushing.

I used the layout line (circle) as a guide while hogging .080" passes. Darn chips where hot!

Snuck up on the finish dimensions for a real nice fit.

Test fit on the link.

I had an old 5" hydraulic cylinder that was scored on the inside. I never throw stuff like this out as it can be repurposed . The 2" ram has been used up on several tooling projects. The cylinder OD fit the Links's profile perfectly. Back to the band saw.

Here you can see the deep score inside rendering this cylinder useless.


Chucked up and faced both ends. Here you can see how well the link fits allowing the bushing to be pressed through.


The set up.


Walked it over to the press as one and it worked out great.

Going.....going.....

Gone!

One more to do. I hope the new ones go in as well as this one came out.


Paco

 

[4GSR]

Paco,

I like your fixture plate you have there. That is a nice piece to use on the press. I got to make one!


Thanks for sharing.

Ken

 

[rwm]

I also made a tool holder made out of 7075. Haven't used it enough to determine if that was a mistake or not. View attachment 250163

By "mistake" I assume you mean using aluminum? It looks great. Let us know if it is rigid enough.

Robert

 

[ddickey]

Yes, that's what I meant.

 

[Firestopper]

Paco,

I like your fixture plate you have there. That is a nice piece to use on the press. I got to make one!
View attachment 250437

Thanks for sharing.

Ken

Hi Ken,
Back when eBay had plenty of deals, stuff like this could be had cheap. I gave around $20 for it plus shipping. It’s ground flat and is handy for layout and press work. It was almost too small for this fixture. You could make one from a flame cut remnant drill/tap and face mill or have it ground. I normally don’t worry about securing bushings for pressing but this one needed to be IMO.
Always happy to share as I continue to learn from this site and folks like you.
Paco

 

[4GSR]

I have several pieces of steel plate about that size. In fact, one has been ground but its like 1-1/2" thick! Too heavy for me to handle. I do have some around 1" thick and can easily be surface ground on my SG.