Here comes the 'Sun'

[Jasonb]

One other thing to think about is the size of the die and your die holder. If you are trying to put a 13/16" OD die into a holder meant for metric 20mm OD dies you will end up with problems. Similar with 1" dies into a 25mm holder.

[redhouseluv]

Sorry, I should have stated, it's the pin which holds the banjo; 1/8" one end and 7BA at the other. I tried again today by screwing in the centre screw on the die, but it made no difference 

I've ordered a new die and finger-crossed it'll work!

[redhouseluv]

One other thing to think about is the size of the die and your die holder. If you are trying to put a 13/16" OD die into a holder meant for metric 20mm OD dies you will end up with problems. Similar with 1" dies into a 25mm holder.

Hmmm.....I never thought of that, I'll check that

Checked - it's for dies 1 1/2" 1 5/16" 1" 13/16"

[propforward]

Make sure to put a shallow angle chamfer on your pin to help give the die a bit of a lead in to get started.

[redhouseluv]

I think I'm getting close and have all the essential elements machined. I assembled the crankshaft, conrods and pistons and holding the flanges on by hand, have rotation!

I can see already the flanges need fettling in order to align the bevel gears correctly both horizontally and vertically, but that's a job for another day with a fresh head 

https://www.youtube.com/shorts/ny7ggdQ5_Lw

[redhouseluv]

I've been fettling away and come upon a problem which I foresaw earlier and left until later .......

In the diagram below it shows a 3/8" spot face where the underside of the bevel gear meets the crankcase.

1. I presume a spot face can be created using a 3/8" end mill?
2. It is the centre hole of the 3 on the LHS in my photo which requires the spot face
2. The problem can be seen in the 2nd photo where I'm holding a 3/8' drill bit, it is touching the edge of the crankcase
3. How to I create this spot face without damaging the edge of crankcase?

[Charles Lamont]

One way is to make your own cutter. I made this one for a job I needed to back-spotface, ie from the 'wrong' side, but I made it to cut both ways.

 

[redhouseluv]

That looks perfect for the job!

I can see its a cutter on a shaft, how is the cutter made and from what please?

[redhouseluv]

I wonder if I bought an M10 counterbore cutter (nearest to 3/8") and machined the pilot to fit the 5/32" hole? Is that even possible as the cutter would be made of very strong material?

[Charles Lamont]

The cutter was made from a piece of 1/2" silver steel. The teeth were milled with an endmill. I hardened and lightly tempered it, and probably stoned the edges. Not good at posting drawings but here is something. It is mounted on a piece of 1/4" silver steel.

The pilot on the bought spotface cutter would need to be ground.

[redhouseluv]

Thanks Charles, I'm going to have to ponder over that, not sure I have the ability to undertake that!

[john mills]

the cutter does not need to have 4 teeth even a single cutting edge will do most ones i have made have 2 teeth 
john

[Jasonb]

Please don't buy and M10 spotfacer. it is meant for a clearance hole for an M10 fixing so about a 25mm body.

Long series end mill would do it if you have one although they don't leave a perfectly flat face. If you have less than 3/16" to the edge of the casting then whatever you use will hit the edge so a guided cutter is better as it does not get deflected so easily.

Like Charles I have made my one. The teeth can be filed into a piece of silver steel, just hardened and don't worry about tempering.





This should give you an idea of what the business end looks like just 4 angled cuts to give clearance behind the edge which also form the vertical cutting edge of the next tooth

[redhouseluv]

Thanks everyone, I've ordered some silver steel and I'll make the cutter; I'll try it on a piece of scrap before attempting the the crankcase!

I just want to check, am I mill or filing the teeth?

[Jasonb]

Up to you, either way works. Quickest to try filing first and if that does not work face the end of the bar and set up for milling

You just need to tilt your file 7-10degrees and file with one edge lined up with the ctr of the metal until you get to about half way First two images. Then work your way round until you have the 4 teeth formed, you can go back around and refine it a bit if needed Last image.

Just use the cutter slowly.