The Journal of a Backwards Professor

[mata_66]

For what I understand an interference fit is a press fit.
I don't get the semi-slip part... Half in?

 

[Rosseforp]

Would you explain exactly what that means in plain (non machinist speak) English please, Doug?

The fit is snug. There is just enough tension to keep it in place. It won't fall out, but can be removed easily.

Edit: It is also what we call a "mechanical seal", water and air tight.

~doug~

 

[Cal]

The fit is snug. There is just enough tension to keep it in place. It won't fall out, but can be removed easily.

Edit: It is also what we call a "mechanical seal", water and air tight.

How, please?

 

[AimlessWanderer]

The fit is snug. There is just enough tension to keep it in place. It won't fall out, but can be removed easily.

Edit: It is also what we call a "mechanical seal", water and air tight.

~doug~

Sounds like what we would call a transition fit, Doug. Does this help, Cal?

Clearance fit: Loose fit. No contact between mating faces

Running fit: Close but loose fit, as a brass bush on a shaft. Should turn without wiggle.

Slide fit: Almost size-and-size. No movement intended between the two parts e.g. a keyed gear or pulley on a shaft. Would need an end cap or locking collar to stop it sliding.

Push fit/Transition fit: Essentially size-and-size, but tolerances will mean there's some variation on that. Will need effort to fit and remove, but not much. Will need a light tap with soft hammer to coax it along.

Press fit/Interference fit: On larger components, if you ain't got access to a press, you're going to need a big hammer. Shaft marginally larger than hub. Definite force needed.

Shrink fit: Large interference between the two parts. The only way these two are going together, is with the shaft soaked in liquid nitrogen, the hub heated as high as it's safe to do so without affecting mechanical properties, and skilled fitters who can get the two together quick before temperatures equalise. Not coming apart without severe damage to one or both parts.

 

[Rosseforp]

Slide fit: Almost size-and-size. No movement intended between the two parts e.g. a keyed gear or pulley on a shaft. Would need an end cap or locking collar to stop it sliding.

In between these two.

Push fit/Transition fit: Essentially size-and-size, but tolerances will mean there's some variation on that. Will need effort to fit and remove, but not much. Will need a light tap with soft hammer to coax it along.

Of course having a proper removal tool helps.

~doug~

 

[Rosseforp]

How, please?

See Post 2,265 above.

~doug~

 

[Rosseforp]

Beautiful work, Doug.

Thanks Jim, I wasn't sure how it was gonna turn out at first. I got a couple more new designs in the works.

~doug~

 

[Rosseforp]

I found a bunch of 12.7mm bearing bronze in my toolbox, so I decided to test out my new knurling tool, and see how well my "Pot Chuck" set-up works.
In order to prevent damage to the knurl with the 3 jaw chuck, I inserted a split aluminum tube in the 3 jaw chuck and bored it to the same size as the knurl. Now it holds the handle like a collet, and I can take it out for inspection then put it back in and it still runs true.
I used to do the knurling last, and usually scrapped at least one handle in the process. This way I can do the knurling first, and if it turns out crappy I don't have a whole day's time wasted.

It is an "Old School" trick they don't teach in trade schools or college.

This is what it looks like while I think about what the end piece will look like.

Not sure yet if it will be brass or titanium.

~doug~

 

[Rosseforp]

BADGERary
Monday SOTD

Razor: Gillette Red Tip (A4)
Blade: Gillette Wilkinson (4)
Brush: Torga Mistura C3
Soap: Fine Italian Citrus
ASL: Aqua Velva

I'm starting to get back into daily shaving, but yesterday was the Chinese New Year, and WhichyPoo says it's bad luck to shave on the New Year, so I skipped shaving yesterday.
My WR2 didn't leave much to shave anyway.

Tonight my Birth Quarter Red Tip delivered a very pleasant one pass shave.
There was blade feel, efficiency, comfort and a song as the blade buzzed through 2 days of stubble.

My Red Tip, now beautifully refinished by Chris at Back Roads Gold, is comfortable enough for a two pass daily shave, but with two passes I would have to wait a day in between shaves.
I'm pretty sure I will have enough stubble to shave tomorrow.

The Witch hazel felt nice, the Aqua Velva refreshing, and the Nivea balm to finish up.

Have some Great Shaves

~doug~

 

[flask28]

BADGERary
Wednesday SOTD

Razor: Lupo95SB
Blade: Gillette Wilkinson (2)
Brush: Torga Mistura C3
Soap: Zingari Man Wanderer
ASL: Layrite No9
View attachment 1590639
For my final shave of the Gamechanger vs. Lupo comparison experiment I loaded up my Lupo95SB with a Gillette Wilkinson (2).
Ten swirls of the Wanderer and the Mistura delivered a nice fully hydrated lather, thanks in part to the Captain's Choice lather bowl to get it started and the PAA brush warmer to keep the lather warm for touch ups during my one-pass shave.

The Wilkie felt smooth, sharp, and efficient in the Lupo, but for me, the GC84-P is more comfortable. This is not to say that I couldn't shave everyday with the Lupo95, but If I had to choose, the GC84-P wins every time, and I also prefer the full length guard over the cut-outs the Lupo is famous for.
Now if only there was a GC95-P to really complete the experiment....

The Witch hazel felt slick, the Layrite No9 was soothing as always, with Nivea balm finishing up a Nice Close Shave.

Have some Great Shaves

~doug~

Thank you for doing this comparison Doug. It was super helpful and entertaining to read, as well as timely. I've got the 64-P and the 84OC, sounds like I need to add an 84 plate.

And your handles are fantastic!

 

[Guido75]

Amazing brass handle there Doug!! Wowi! Nice to see you refound your lathe mojo again!!

Guido

 

[Sweeney_]

I usually reach for my 95 lupo sb over the 68 or 84 GC but that's what makes us different. If we were the same, we'd all be driving 'stangs. Oh wait...

That Red Tip is gorgeous

 

[Chan Eil Whiskers]

Amazing what you can learn from Doug.

(Not that I've learned anything, but you know what I mean.)

Happy shaves,

Jim

 

[Rosseforp]

I usually reach for my 95 lupo sb over the 68 or 84 GC but that's what makes us different. If we were the same, we'd all be driving 'stangs. Oh wait...

View attachment 1593393

That Red Tip is gorgeous

Thanks. So is you're Stang!

I've got the 64-P and the 84OC, sounds like I need to add an 84 plate.

The GC84-P just delivers. It was the first razor I could shave ATG on the first pass with.

~doug~

 

[Rosseforp]

Finished.

Ready for tonight's shave.

~doug~

 

[Guido75]

A M A Z I N G !!

I feel a severe case of HAD coming up again, just as I thought I had everything under control for this year.

I like the knurling on the plug as well. Was the second photo after the first or did you make different plugs?

Cheers,

Guido

 

[Guido75]

What I also like is the way you use mixed metals between handle and razor head. My OCD has been that these ideally match, but a handle like this changes that perspective I must say.

No washer?

Guido

 

[Rosseforp]

A M A Z I N G !!

I feel a severe case of HAD coming up again, just as I thought I had everything under control for this year.

I like the knurling on the plug as well. Was the second photo after the first or did you make different plugs?

Cheers,

Guido

I took them at the same time, just different lighting.
~doug~

 

[Rosseforp]

What I also like is the way you use mixed metals between handle and razor head. My OCD has been that these ideally match, but a handle like this changes that perspective I must say.

No washer?

Guido

It's brass, washer's are for heathen's and lug nuts.

~doug~

 

[Guido75]

It's brass, washer's are for heathen's and lug nuts.

~doug~

Ehh I meant to protect the EFBT baseplate. But maybe I am a lug nut myself?!