Prop re-pitching and casting.

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Terry, you have WAYYYYY too much time on your hands!!!!!! LOL

Seriously though, this is really cool stuff!

Steve Ball
 
Hi Terry,

I hear you, very difficult to hold props to work them. Now you take the hub and bore away and it doesn't leave you much to hold tight and control. Your set is about as good as I've seen. I used to regrind the O.D. on the counterbores to get the size I needed. When I did the 4 bladed props I used two 2 bladed props, I cut the hub halfway down from the top on one prop and halfway up from the drive dog side of the other and silver brazed them together. I had overbored the I.D. and made a sleeve to keep them centered and a fixture to make sure they were indexed 90 degress apart. Neat Stuff!!

Thanks, John

I've seen some of your 4 bladed props, nice work!

Thought I could hold the blades with just the 3 screws but glad I used the Cerro metal, they wouldda moved fur shur! That BeCu is much tougher than I thought, even in an annealed state.

http://www.shop.boltonmetalproducts.com/?gclid=CJyhr7TErroCFYxAMgod0zcAnQ

How did the brazing hold up? Did you use 45% Ag rod?
 
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Hi Terry,

I used the silver solder Ed & Dee sold. I still have some as well as many other grades. If you ask Ed he'd probably tell you if it's 1/2 hard 3/4 hard or ??

The 4 blade props I did for Jim Babby were never supposed to be run, I made him sign an affidavit to that effect but I think he did run them. I just didn't want the liability and needed the protection. I've heard some people running .101's have tried using the 2267's, they are really thin at the hub and Tom wouldn't build them up. To keep them from throwing blades people are building a fillet at the hub with silver solder, I've not seen them but it sounds feasable and I'd surely try it as well as heat treating them along with it.

Thanks, John
 
Gonna take some cleaning up but I think I got a good bond.

Oxy/acetylene worked better, plus got some ideas for the next one... :)

DSCN2610.JPG


DSCN2621.JPG


DSCN2616.JPG
 
Terry wins the... "High Tech Canadian Red-Neck" award... Roy would be proud... ;) just kidding beautiful work AGAIN Terry.
 
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She cleaned up nice:

DSCN2630.JPG


Unfortunately it threw a blade shortly after launch. Thought the solder wudda flowed into the joint, oh well.

Next one I'm gonna tin both parts and leave a good fillet! :)

DSCN2641.JPG
 
Hi Terry,

Bummer! You probably already know this but I'll add it anyway. Your setup acts as great big heat sink and it may pull heat faster than you tought. When you redo your brazing bring the heat up slow so the fixture comes up along with it. When brazing the base metal will be cherry red or almost depending on what temp brazing rod you have. Brazing rod flows to the hottest spot so you can sweat it in much like copper water joints only at a higher temp. It is possible to also over heat the rod and have it oxidize leaving a weaker joint. If it were me I'd consider building up a larger filet at the hub on both the front and back and leaving it there for added strength. Another thought would be to contact a welder and see if they could TIG weld it.

Thanks, John
 
dumb question.. what about preheating the jig in a oven ahead of time and then filling the blade terry? like john was talking about..

any idea how ernie l used to do his?

chris
 
Hi Terry,

Bummer! You probably already know this but I'll add it anyway. Your setup acts as great big heat sink and it may pull heat faster than you tought. When you redo your brazing bring the heat up slow so the fixture comes up along with it. When brazing the base metal will be cherry red or almost depending on what temp brazing rod you have. Brazing rod flows to the hottest spot so you can sweat it in much like copper water joints only at a higher temp. It is possible to also over heat the rod and have it oxidize leaving a weaker joint. If it were me I'd consider building up a larger filet at the hub on both the front and back and leaving it there for added strength. Another thought would be to contact a welder and see if they could TIG weld it.

Thanks, John
Thanks John, my toolmaker buddy said the same. The braze flowed very well once I got the right temp, just didn't go right into the joint like I thought, tinning both parts will make sure it does! Did my usual thinning job but will leave a fillet next time...

dumb question.. what about preheating the jig in a oven ahead of time and then filling the blade terry? like john was talking about..

any idea how ernie l used to do his?

chris
Sounds like a plan, the braze flows around 1100F, I'll put the whole thing in my kiln at 1000F for a couple hours then go at it. :)

I'll get it, I'm just that stubborn!

Did Ernie Lafleur braze on props?
 
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