Impeller question?

[MikeC]

Good post Jer, How can a company claim to be doing R&D when it can even supply basic dyno info?
Also, I've heard that the PWC's have been making lots of progress these day's, funny, I heard (I have not looked it up myself yet) but I've heard that the latest PWC pumps are starting to switch over more and more to a mixed flow type pump (like a Berkeley).
Here's a neat one, http://www.wetwolf.com/
MikeC

[Jetmugg]

RiverDave:
It's good to have another brother in the foundry industry. I'm a metallurgist/production manager at a centrifugal foundry in Indiana. I have been advocating the use of more sophisticated materials for use in impellers for a several years. At one point, I even gave one of the pump manufacturers (Chet's favorite) very specific written instructions including casting procedures for making a cupronickel impeller. They said the cupronickel impeller didn't work, which probably means that they didn't get the chemistry correct, and then gave up on the idea. The current crop of duplex stainless steels also seem to offer significant improvements over the 300 series SS which is currently used. Thinner, lighter, and stronger impellers are easily possible. This seems to be an area of pump technology which is mostly ignored by the manufacturers.
SteveM.

[schiada96]

RD what about v-drive props got any Ideas. We need another prop guy there is only a couple of them out there. I don't think a casting would hold up, but maybe with some trick material it would. A stainless three blade from menkins cost about $800.
3-D systems is slow right now.

[Eric]

Originally posted by OLDSQUIRT:
Eric, you owe me a beer! I laughed so hard that I knocked mine off the desk!!!!
If we ever cross paths on the lower Colorado I'll be glad to replace that beer!
Originally posted by 1quickjet:
Eric, That first pic looks exactly like my greyhound, did you adopt/rescue? I was crackin' up!
It's not my dog, I just found the pic on the internet and it made me laugh so I put it to good use. I had a little too much free time at work yesterday as you can tell. Photoshop can be dangerous in the wrong hands...
Eric

[jim lee]

I did a little turn in the foundry industry. Wrote the OS for a investment casting mold assembly robot. We designed and built the thing in our high tech. world. Thinking all is fine and dandy. One day, my boss did a trip to one of the foundries that was to use the molds. (Is that what you call the piece that burns up?) Anyway, he returned a couple days later. Totally dissalusioned and glassy eyed.
"What's the matter? What happend at the foundery?"
He looked at me, puffing on his cigarette.. "It was like suddenly being drug back to the dark ages! Its this horrible dark building with a DIRT FLOOR! People running about with ladles of hot metal.." His eyeys glittlered with the horror of his memoroies. Looking at our robot he continued. "They are -never- going to be able to understand this thing.. It looks like it was created in a labratory.. It'll never survive.."
At the job site, I think the machine killed more production than it helped. Whenever they'd turn it on, it seemed like -everyone- would stop what they were doing and come watch it run. Some of the younger employees undertood the machine. The UI was fashoned after video games and they took to it like fish to water. Unfourtunatly, it went right over the management's heads.. Oh well..
I digress, my real question is: For the racers.. Why not Just plain 'Ol steel impellers? Race impellers tend to get reworked a lot, and I'd think steel would be a -lot- easier to work on. As for corrosion.. Sheesh, they're only wet about 2 times a month and then only for a few minutes at a time. Cheap too, over cut your A to a B- ? No big deal pop out another impeller and go at it.
If you wanted one to last longer, couldn't you plate them with something tough?
I was leading up to this question on the "other board" but this thread is already here.
P.S. The doggy pic.. Nearly peed me pants! ROFL!!
-jim lee
[This message has been edited by jim lee (edited November 20, 2001).]

[RiverDave2]

Originally posted by schiada96:
RD what about v-drive props got any Ideas. We need another prop guy there is only a couple of them out there. I don't think a casting would hold up, but maybe with some trick material it would. A stainless three blade from menkins cost about $800.
3-D systems is slow right now.
A casting won't hold up?? How do you think Mercruiser makes all there propellers? As a matter of fact call Chad Hill and ask him how he made his record settin APBA propeller! http://free.***boat.net/ubb/biggrin.gif Something tells me that they'll hold up just find for most applications.. The only thing I wouldn't use them for (without doing some material research first) is for fuel drag boats.. Everything else would be fine..
As far as why they don't just make them out of plain old steel is becuase of corrosion.. That's why everything is stainless. Plus some stainless's actually have better matl properties.
I agree that a foundry is a god awful place that I'd never want to go too again... but if you have a couple of kick ass ways of making patterns overnight there's no faster way of getting a complex metal part in your hands. It's all about the pattern.. The thing that "burns up" is called the "investment" i.e. Investment casting. You invest your pattern to create a casting.
RD

[HBjet]

Originally posted by ChetCapoli:
Why not recommend bronze and he can save some money?? Why doesnt anyone think of that? Some friend you must be eh? They are half the money and are good to at least 1500hp. I still plan on running aluminum until i get my setup dialed in, (close to 700hp)then i'll run bronze. If the aluminum grenades(which is a given right?) i'll let you know. So far so good the past two seasons.
You people in southern cal should really open your eyes to the rest of the world we live in.
"the one and only number"
YOU ARE TOO MUCH DUDE!!
Chet
P.S. as blowndragboat would say...get the D$#^ out of you mouth.
Chet must be dialing in his motor right now, and I just can't stop myself from finding more information about what Chet has posted. See, before slamming Chet which I'm about to do, I took the time and called around again. Today I called Don's Pump Service. Nice guys over there. Anyway, I asked them about aluminum impellers and how much HP can you put to it before you need to step up. They answered as Chet has stated, they used an aluminum one with a 700HP motor. Now, that was in a race boat, with perfect water conditions, and the pump was never un-loaded and then re-loaded. I asked, what about a river boat, like at Parker, or at a lake. I was told aluminum was good up to 500HP, and anything after that it could and would start to crack, etc... I asked what was the next type of impeller I should use, Bronze? I was told, NO, Bronze is no good, use stainless. I was told no one is making Bronze anymore, and the only ones who are is Aggressor. I asked, are the Aggressors good? Again, I was told, they have only heard bad reports about the Bronze Aggressor impeller and wouldn't recommend it. I mentioned that I saw Aggressor offers a Stainless, but it is custom order. They said they have only seen one, and weren't impressed at all with it.
So there you have it. I called Don's Pump Service Chet, and they told me everything opposite of what you are saying. So please get a F'ing clue and stop mouthing off before you even know what the hell your saying. Example, "Use bronze, there good up to 1500hp" Dude, any good pump builder wouldn't tell you that, I don't think Don's Pump service would like you Yelling there name out and then following up with what works and what doesn't when it is the exact opposite of what they told me.
Since you are just BS'ing here, why don't you just take your boat which has so much hook in it and go fishing, atleast you would get some seat time sitting on the beach wondering why you sound like such an ass.
HBjet
I'm not one to go out of my way to prove someone wrong, I think we all can learn for each other, but I just had to see if Chet really knew anything about what he was saying. Now, if Chet comes in here and says, ok, I was miss informed, fine, great, that's cool, everyone gets miss informed information, that's not there fault. If someone doesn't agree with something I've said, I'm not going to call you a Dumb Ass like Chet has before, or that you East coat boats are doing it all wrong. I'm going to tell you to call who I've talked to as Chet has before in other topics. I called, and this is what I found. I invite anyone to prove me wrong, because then I'll be more knowledgable. Thanks
HBjet

[schiada96]

Rd I've asked Chad Hill the same thing about cast stainless v-drive props he says they wont't hold up for a high performance ski racer / cruser. This v-drive prop thing sucks with only two people out there making them.

[Jetmugg]

I love a good materials/ process discussion. Foundries do tend to be hot, dirty, stinky, dangerous places. I love them. I'm a degreed metallurgist, but I still love to go and mess with the hot stuff. Today, I personally poured a 22,000 pound carbon steel casting. (filling in for a guy who left early) The smoke, liquid metal and steam will make your eyes water and your lungs ache. There is nothing like knowing that you are making something useful.
We pour over 150 different alloys. Part of my job is to specify materials for different applications. I personally have a soft spot for casting the stainless steels. I can make a cast stainless steel which will have a tensile strength over 200,000 p.s.i. Anyone who says that castings will not hold up doesn't know the full story. Castings are used in everything from nuclear submarines to jet engines. Mark these words - Duplex Stainless Steels (austenitic and ferritic) will some day be used for jet boat impellers. When they do (hopefully soon), the 300 series stainless will become obsolete. Duplex steels have already replaced 300 series SS in paper mills, steel mills, jet engines, and many other applications which are far more demanding than a jet boat. One of these duplex stainless steels would be best suited for an all-out race application.
The cost of a duplex SS is not much more than a 300 series SS, but the foundry processing is more advanced. Besides, the material cost of a finished product is only a very small percentage of the total cost. A typical stainless steel costs less than a dollar a pound in terms of material cost.
My take on bronze is that most bronze alloys are already obsolete, but they are still useful mainly as machinery bushings, bearings, and sleeves. Bronzes are easy to cast and machine (lower cost), but the mechanical properties generally leave a lot to be desired. Even the "mag bronze", which is actually a manganese bronze, has good strength, but sacrifices ductility (it tends to be brittle). My best recommendation for medium-high horsepower applications (middle of the road costs) is for a 70/30 Cupronickel material, which is nearly as strong as the current 300 series stainless, but is much easier to cast, machine, and weld. 70/30 is the U.S. Navy's material of choice for propulsion shaft sleeves for virtually all of the large military ships and boats (U-boats). I would be glad to help any foundry or pump manufacturer to develop a cupronickel impeller for medium-HP applications, free of charge. If anybody knows a foundry which is currently making jet boat impellers, I would be glad to provide assistance.
SteveM.

[RiverDave2]

Well there you have it... I have the CAD and pattern making facillities, all Steve has to do is give me the shrinkages and I'll program that into the pattern for invesmtent... Anyone want to step up to the plate and make something worth making for once?
Steve, have you ever seen SLA QuickCast or SLS (DTM) patterns for investment casting? Like the picture above?
RD
[This message has been edited by RiverDave2 (edited November 20, 2001).]