Reply With Quotescott call me Danny
yeah I agree. if your smart enuff to build the damn thing, then your smart enuff to know if you should. Scott knows what he's doing here, and I wouldn't pay those prices for something I could fab either. Why put your life in someone else's hand's you never met, says he will use the right stuff, heat treat it correctly etc etc then find out it was made in CHINA!!!The guy I got the prices from (who's name I will respectfully not mention) has made struts for years, and I wouldn't have any problem trusting his work. I'm just not going to pay his price. I can screw a couple up, and take a month to get it right, and still be ahead! :sqeyes:
BTW...which Scott are you referring to? Me or unchained?:idea:
OK...this has been great input. Really valuable to me, and I thank you guys for the info. Since there's so much thought going into this, I have one more question. Originally I thought it might be a good idea to mill a reciever groove in the barrel for the fin, say .100-.150 deep. Now that I think about it, though, and thinking about the weld and the attachment, I'm not sure it's a good idea. I'm afraid the bottom edge of the groove will be a stress riser and create a break line at the base of the vertical fin.
Any thoughts?
Thanks again.
scott call me Danny
Originally I thought it might be a good idea to mill a reciever groove in the barrel for the fin, say .100-.150 deep. Now that I think about it, though, and thinking about the weld and the attachment, I'm not sure it's a good idea. I'm afraid the bottom edge of the groove will be a stress riser and create a break line at the base of the vertical fin.
Any thoughts? Thanks again.
I would prefer to bevel off the strut fin where it meets the barrel.
A 1/4" fillet weld on each side should be sufficient. That would be nearly 8" of weld on each side. Actually the weld connecting the fin to the barrel is not going to have near the stress as compared to the weld holding the fin to the mounting plate. There is going to be significant leverage on that one. That's why I considered using a T section of a steel beam. No weld, cheap material that I have in stock and a radius where the two meet. After machining it will all look the same.
Beams now are made from an A50 grade material as compared to beams from 15+ years ago that were made from A36 material. The number designates the tinsel strength of yield in 1000's of # psi.
I like the suggestion on the DOM material for the strut barrel. I would prefer to use an undersize ID so it could have final machine work after welding.
I've made struts for years and I don't think 1500 for a strut is way out of line. Have any of you priced a chunk of 17-4 to make the pieces for either a drop thru or a bolt on? You can't buy tube to make the barrel from 17-4 - you have to buy round drill and bore it. Making the pieces is the easy part. The welding is critical, welding down the length of the tube is not the problem - it is welding across the tube that pulls the barrel ends up. I've made plugs that I press in before welding to keep the ends from pulling up. As for making from 4130 - rod choice and heat treat are critical.
A50 vs. 150 ksi heat treated 17-4 Id pick the stainless everytime.
Barber welding makes these, and they have all the expertise and tools. Are those prices reflective of theirs? I have a cruiser running GN, and was considering a switch from bolt on to drop through strut so I can custom fit the shaft angle. Am I getting into the deep end of the pool (expense-wise)?
Barber welding makes these, and they have all the expertise and tools. Are those prices reflective of theirs? I have a cruiser running GN, and was considering a switch from bolt on to drop through strut so I can custom fit the shaft angle. Am I getting into the deep end of the pool?
You are already in the deep end of the pool...LOL!
Who has had a strut break/fail on them ?
Where was the weak link ?
You could certainly make the strut out of any material including aluminum, but the stronger the material the thinner and lighter the section could be, and the less drag in the water. I suppose if cost was no object then Titanium would probably be the best material.
Who has had a strut break/fail on them ?
Where was the weak link ?
You could certainly make the strut out of any material including aluminum, but the stronger the material the thinner and lighter the section could be, and the less drag in the water. I suppose if cost was no object then Titanium would probably be the best material.
Having seen propellor blade failure the main goal with a strut is to be strong enough to handle a prop shaft holding a prop with one blade...again just my .02.
Having seen propellor blade failure the main goal with a strut is to be strong enough to handle a prop shaft holding a prop with one blade...again just my .02.That makes huge sense. Not the normal stress to worry about, but the extreme condition one may see, and still stay in one piece.
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