Making New Injector cones

[keith1500]

Having read the thread on injectors and whether the Linden chamfer makes any difference it dawned on me to have a go.

Now i bet theres many people who like me have an old injector that has been replaced and merely resides in the parts box no longer in use. So, i am thinking theres not a lot of work in making a new set of cones assuming you can make the D bits in the first place !

Any good hints or tips inc photographs etc on making a D bit or other means of forming a nice taper in an injector cone?

Cheers
Keith

[baggo]

Hi Keith,

I made my reamers from silver steel with the tapers turned in the lathe by setting the topslide over at the required angle. I then filed away about 1/3 of the thickness and hardened and tempered them. They were then ground down to half thickness with a grinding wheel in the lathe chuck. The reamers were clamped in the tool holder and fed across the grinding wheel, advancing the cut a few thou at a time. You have to be very careful as the reamers are quite flimsy! Also, make sure you get as fine a finish as possible on the reamers, especially the flared one for the entrance to the delivery cone.

When I make another set, I will probably leave the reamers dead hard as it's easy to twist them if they are too soft. They cut very well in the brass that I use for the cones but it's a case of cut a bit, withdraw to clean away the swarf, etc.



I'd recommend DAG Brown's articles on making injectors for anyone considering making their own.

Have fun!

John

[keith1500]

John,

Thanks for your reply and the photo. This made me recall seeing this from your web and managed to find it again. So I'll restudy your notes and have a go at making the bits. I have been thinking about investing in a set of collets for sometime and this adds to the reasoning!

Cheers
Keith