20 pounder pressure jet nose cone spinning jig

[Viv]

Just thought I would post this for the interest value, this is the spinning jig I recently made for the 20 pounder pressure jet engine.

Hows it made? well take a 6" by 7" mild steel blank and a sharp file:-)

Viv

[skyfrog]

Hows it made? well take a 6" by 7" mild steel blank and a sharp file:-)

Beautiful mandrel, if not CNC turned this is really a master of piece of work !

Your truly,

[Mike Everman]

Ah, very very nice, viv.

[Viv]

Hows it made? well take a 6" by 7" mild steel blank and a sharp file:-)

Beautiful mandrel, if not CNC turned this is really a master of piece of work !

Your truly,

No we could not quite go the distance for a $80,000 CNC lathe this time:-) so yes it is hand turned! I roughed out the waste material with tip cutters in steps then used a very course file to bring it to shape against a template.

Taking the waste out to a rough shape was simply done by using the two X Y feeds by eye and traversing along the cone, after that I did the rest with a file.

Just to make it interesting this was the first thing I have ever made on a metal turning lathe! shows how good Luc's drawings and templates are as well i think.

I should add that I was at one time one of the top 10 woodurners in England and I spent five years making things like this out of wood by hand:-) seems its a skill you can carry across to metal working:-)

Still busy now for a while as I have one each to do the other engines as well, after that we won't need to buy a CNC lathe!

Viv

[Dave]

Impressive!

[skyfrog]

I should add that I was at one time one of the top 10 woodurners in England and I spent five years making things like this out of wood by hand:-) seems its a skill you can carry across to metal working:-)

Yeah, I guess once you get hold of the principle behind, you'll have very steep learning curve and adapt quickly to new things.

Regards,

[Mark]

Did you use sandpaper to get the final polish or abrasive paste or what and if so what kind? Looks pretty. I hate working with steel on a lathe.
Mark

[Al Belli]

Hi Mark,

When using a file on the lathe, it is very important to keep the RPM low to prevent the " sticky " steel from clogging the file. Oil only makes the clogging worse. If You clean and degrease the file thoroughly, and then fill the " teeth " of the file with chalk ( rubbing the chalk into the teeth thoroughly ), You will find that the file will not clog with steel as easily.
I file to shape, and then use a progressive finish with abrasive cloth strips. 80 grit, ( or 120 to start if the scratches are not too deep ) and then 180, 240, and progressively finer until the desired finish is reached.
I have used 1,200 and 2,000 grit and then Simichrome polish to achieve a mirror finish. Simichrome is available at most motorcycle shops, or directly from Competition Chemicals Co. Also see their info. on Blueaway.

http://www.competitionchemicals.com/

Al Belli

[Viv]

Did you use sandpaper to get the final polish or abrasive paste or what and if so what kind? Looks pretty. I hate working with steel on a lathe.
Mark

Mark, Al summed it up pretty good:-) but I forgot the chalk:-( never mind:-)

Viv

[JOHNEP]

how exactly is that lathe form used, do you have more pics of it?

[Viv]

how exactly is that lathe form used, do you have more pics of it?

Its used to make nose cones to sell to you:-)

Viv

[Mark]

I don't understand how a forward intake integrates with that nose cone?
; )
Mark

[Viv]

I don't understand how a forward intake integrates with that nose cone?
; )
Mark

Well thats another project Mark, this ones for the standard pressure jet engine, the forward intake thing is all to do with some one having some sour grapes about us taking over the pressure jet, they made a little phone call to Michael Stram to cause us trouble.

That didn't work and is due to back fire in a rather a spectaculer way:-)

Viv

[Mark]

Well that's swell. Keep us posted on the details.
Mark