2016 POTD Thread Archive

[Whyemier]

...remember the compression ratio must be 18-1 for best results.

I was not aware of a specific compression ratio so thanks for that information. I'll check what I have and see if its anywhere near that.

I knew there must be more to it than I thought.

 

[Tony Wells]

Think Diesel engine on those fire pistons. That's basically how they work. I've thought about building a handful for gifts, just never found the time. Pretty cool idea and it does work.

 

[intjonmiller]

I read that it was specifically the inspiration for the Diesel engine. Hard to verify that at this point, but it certainly makes sense.

 

[TomS]

The apron on the Summit leaks somewhere, (trying to find where AGAIN). Tried to remove the sight glass to see where the oil level was, it crumbled, (may have been the leak but think I would have seen the oil streak). Made one and had Julia cut me a glass disk. Sealed the disk to the tube with a bit of RTV.


Installed

Removed the guards to check the back of the apron for the source of the leak. Guess I'd never bothered to check the lead screw. Quite a chunk of steel. 50 mm dia and 2 tpi. Guess it needs to be pretty stought to cut 1/4 tpi, the coarsest setting on the quick change.
Of course I've never had a need to cut anything that course. Would you cut that with a conventional form tool or set up a milling device of some sort?

Greg

I cut the 1/4" tpi on this fuel caps using a 3/32" radius form tool. Turned the tool upside down and threaded away from the chuck. The carriage moves quickly even at the lowest spindle rpm.

Tom S.

 

[f350ca]

Nice work Tom. The carriage would be hustling along. The slowest speed on this lathe is 20 rpm, so the carnage would be flying along at 1.3 inch per sec.

Greg

 

[jrstech]

I cut the 1/4" tpi on this fuel caps

Tom, please correct the "1/4" tpi". That would mean 1 revolution or thread for 4" of travel.

 

[Silverbullet]

You've got some very weird gravity in your shop. Are you sure you're really in Utah and not OZ?

Isn't that the state of OZ , UTAHTOPIA.

 

[q20v]

I made a very simple part the other day but it was my first knurl.

The remote stiffness adjuster for my bike shock was missing the knob, which is normally plastic I believe. I made an aluminum disk to replace it.

 

[TomS]

Tom, please correct the "1/4" tpi". That would mean 1 revolution or thread for 4" of travel.

Typo for sure. The thread pitch is 1/4" (.250") or 4 tpi.

Tom S.

 

[rdean]

I made a set of bevel gears 40 teeth 16Dp.


As many of you may know you can not make a perfect bevel gear using a gear cutter as the tooth changes shape as the diameter changes. You can make one that is close by fudging some of the cut parameters and some creative final fitting. These didn't turn out too bad.




These should work for my slow speed application.

Thanks for looking
Ray