What's This?!?!

[TomMoorehouse]

usually i go with 50%

 

[AndyBrown]

usually i go with 50%

Tom, it would have to be an EXCEPTIONAL day to run 70 mph on 50% with a .21 heat race boat.

 

[Tim Kish]

Machining props like this will be awesome for twins B)

Tim K

 

[Don Ferrette]

My sport 40 props arrived yesterday .... amazing! B)

 

[AndyBrown]

OK, for you guys asking about a .21 tunnel prop....we've got one ready. It's a 3857 4 blade. Yep, 4 blades!

I'll post a pic later. Average pitch is 2.25" with the T.E. at 2.5" With four blades this prop will hook up well without needing excessive power robbing cup.

This prop should work well on .21 sport hydros, .21 vees and Cats too.

We will run a special on this new prop until midnight Wed. March 26. $30.

Good boating,

Andy

 

[bradley]

Hello,

Do you have any props for a .67 rigger?

Thanks

Bradley

 

[jaxracer]

OK, for you guys asking about a .21 tunnel prop....we've got one ready. It's a 3857 4 blade. Yep, 4 blades!I'll post a pic later. Average pitch is 2.25" with the T.E. at 2.6" With four blades this prop will hook up well without needing excessive power robbing cup.

This prop should work well on .21 sport hydros, .21 vees and Cats too.

We will run a special on this new prop until midnight Wed. March 26. $30.

Good boating,

Andy

Can you post some pics of it? Definitly interested to see what it looks like.

 

[tnrcboatracer]

How about some 6 blade Rolla look-alikes? Would work perfect for an Arneson type stinger drive.

 

[AndyBrown]

How about some 6 blade Rolla look-alikes? Would work perfect for an Arneson type stinger drive.

I made a couple of 5 blade props this weekend. One was 30mm X 63mm. The other was 38 X 63.

They are complete with trailing edge kicker and the 30mm prop has a 2.1 pitch/diameter ratio. About what full size boats are using.

It looks identical to the props Rolla, Herring and Mercury are making.

If I knew the amount of camber/progression, rake and skew that they were using we could test them on our models and compare them to what we normally use.

I'd post pics, but the tools I have didn't fit in between the blades correctly so the finished product does not look very good.

As soon as I can get the correct tools I'll make some for the .21 & .45 boats.

 

[tnrcboatracer]

Can't you just call the big prop OEM's and ask for that info? I'm sure they would be glad to give out that to you; it would save so much CMM time

I think that a 5 blade 3863 may be a bit much for my mono. I guess I could give it a try.

What size tools are you using for this. We once had a vendor using 0.5mm dental burrs to make the EDM graphite electrodes for a 25 ton mold for one of our vehicles. We were molding the snow screem intregrally into the cowl covers. Usually it is post welded from mesh screen stock, but we molded it in to save cost.

Andy, PM sent.

Thanks, Jon

 

[TonyKilbarger]

Curious how long it takes that machine to make a prop? The props look nice but I cannot imagine it to be a cost effective method to mass produce a prop unless it is a $200 prop. Unless it could crank out a dozen an hour and as fine as the finish looks I imagine it takes much longer. Casting still seems most economical for props to sell, but the machine sure makes them nice. Can't imagine you could make much money doing props on a machine of that sophistication.

I also can't imagine an aluminum prop holding up well. BeCu is pretty tough stuff.

I could really use a couple cranks and a piston and liner set for a MAC 45.

 

[Rudi Arnesen]

It seem to me that the design off the props are new, and there is being put a effort into making these new design work.

Why simply not make copy off what we are using today, like 1667 pitch 5,4, - 5,6,- 6,0 and so on.

In that way CMD would be guaranteed to sell allot off props.

Rudi

 

[fishinghole]

Andy,

Will the 4 blade .21 tunnel props work in the Sport class? If so I want two. PM me your mailing address.

John

 

[speakerboy]

Hello Andy .. congrats on the new prop's and the amazing work you did to them . i wonder if you are gong to make some of those for the .90 and gas riggers .. i have a 1667 from you for my gas rigger , but i can image a prop for those riggers in built wit hthe new techno your doing right now ..

best regards ,

Jeroen (tune )

the Netherlands

 

[BACKEMF]

I'm so jazzed I can barely wait to get the three I ordered.

I don't think they will have a problem selling props and new props are much better than a CNC copy of an old design.

Finally a step forward in RC boat props. B)

 

[Rudi Arnesen]

I don't think they will have a problem selling props and new props are much better than a CNC copy of an old design.

Why should a new one be better?

 

[Darin Jordan]

I don't think they will have a problem selling props and new props are much better than a CNC copy of an old design.
Why should a new one be better?

I don't know about you guys... but I have VERY few props in my box that even remotely resemble the way they came from Octura or ???... Most have cuts and tweaks and cups... etc...

If I can get my hands on some props that were designed sometime in this decade... I'm in! Surely improvements in design tools and manufacturing equipment has yielded benefits and THAT is why a new one could be better...

 

[Ron Olson]

I'm looking that Andy's props this way, consistant pitches on every blade, no BC dust to deal with when doing up your own, competitive prices for those that buy SB&P props.

 

[BACKEMF]

Think of the best tweaked prop and then say scan it in 3D CATIA software. Then use some other software created specially for designing/optimizing surface piercing propellers and then you can tweak out any mistakes or inefficiencies. Then you just pump out the G-code and marry it to the 5+ axis machine and let it do its thing.

Fun, wow! .....I'm a bit biased since I love working in 3D software. Haven't tried a prop yet, still mulling it over in the brain. I could try Auto CAD, Inventor, Solidworks or MasterCAM.

 

[BACKEMF]

Poetry in motion...

http://www.youtube.com/watch?v=fXWMDN5amzE...feature=related