Mike's Build Log

[Mike Everman]

It’s definitely going to work.. I hooked up the stinger and got a great starting resonance and grumble.
Bad news is the stainless has work hardened somehow, and is just undrillable. I need some carbide bits to continue.

[tufty]

How bigness the carbide?

[Nick]

It’s definitely going to work.. I hooked up the stinger and got a great starting resonance and grumble.
Bad news is the stainless has work hardened somehow, and is just undrillable. I need some carbide bits to continue.

Exciting stuff! - Mike - not sure this works with SS but could you just heat the stainless to a red heat and let it cool slowly to anneal it? - should be ok to drill again then.

Looking forward to the next instalment!

Nick

[Mark]

Make it go.

[tufty]

Stainless is an absolute mofo for work hardening. Annealing should be possible, I guess - from memory 304 and 316 are somewhere between a bright cherry red and a dull orange, erring on the orange side, holding for 3 minutes per mm thickness, and then let it air cool. I checked my carbide stocks, I have some endmills but nothing much in drills. You might well get away with a HSS / Cobalt drill bit, sharpened at 135° or so rather than a "standard" bit, but it's still gonna be a bugger to tap, might as well get the oxy torch out :)

[Mark]

I had to anneal and then tap this lid with a 1/2 inch NPT Pratt and Whitney tap for a tri clover jar I had and it was no fun. After red heating the lid I used a cobalt drill bit and then the tap. What a pain just to go through a little over a 1/4 inch thick 316 stainless steel. The edge of the lid is sloped for the clamp and the center thick.
https://www.pulse-jets.com/phpbb3/downl ... hp?id=9454

[Mike Everman]

All ready to go! I found some tiny tapered carbide endmills in the “box of woe”, looks like the nose of it is .025”. Punched in quite nicely.

The starting stinger has metering and a pushbutton switch. I’ve got a valve on the main feed that is probably not big enough.

I’ll check the fuel holes with pin gages, I’ll bet it’s a mix of diameters from .026 to .030.

I’ll try to run it tomorrow!

[Nick]

Looking Good Mike! - can you video the start up?

[metiz]

I'm in a different time-zone. Is it tomorrow already?

[Mike Everman]

I am GMT -7
Best I can do is about 5pm today my time, sorry!

[tufty]

Leaves enough time for the video to upload before I wake up :)

[Mike Everman]

GAaa, well, I've got to get more serious about my plumbing.
I've always used the tank valve, so me little push fittings and plastic tube never developed any appreciable pressure. Now, I'm valving in two places at the motor, and multiple shenanigans have ensued!

I am running into this a lot these days, the "false success complacency".

Very disappointing delay! But it's going to work!

[tufty]

But it's going to work!

I've already been to work! Where's my bloody video!!!?

Of course it's going to work. Plumbing issues are minor.

[Nick]

Ahhh righto - the last few yards are always the hardest!

[Mike Everman]

It's the 90-90 rule:
The first 90% of the job takes 90% of your time.
The last 10% takes the other 90% of your time.

Sad to say, I've got to hit the road for the weekend tomorrow morning to visit a dear and terminal friend, so our collective jollies will have to wait...