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Andy Brown, please may I ask your advice?

What would you suggest for a mono prop used in races. Boat is MONO II class (12 NiMH 4200 IB or similar cells :running 6 minutes - motor has 2000 -2400 rms /v depending on type) Boatdimensions : 60 -75cm most of the time stepped. Common used in Germany is Graupner 2318.42/45/sometimes 48.

Same question for Mono III class (20 cells Ni MH 4200 IB or similar) running 6 minutes. Boat is 80-90 cm , most of the time stepped. Motor : 1400 -1700 rms/V.

Thanks for your advice and keep up the good work.

Happy boating.

Jef.
 
My son is running a Delta Force 67 with an old CMB 45 EVO on 40% nitro.The prop we have found to suit the combo best is an AB X450/3 pitch 3, 8.

The boat has been very stable and very fast with this propeller.

Today we hooked up the AB 5083/3 prop. When I launched the boat the water was like mirror and the prop seemed too heavy, as we could not get up the revs. The roster was high (more than 12 feet) and the speed was not what I would call fast. After a couple of rounds the boat itself had made some waves and that was enough for the boat to rocket away.

I have never seen such a difference from a prop to another and this prop is the right prop for our application.

The rooster was very low (a guess would be 2 feet) and very short.

I can highly recommend this prop for the DF/CMB combo.

The boat is now superfast and super stable and my son said it was like driving a bigger boat.

What other props do you recommend for us to try Andy?
Rudi,

Thanks for the report!

That is a very interesting result. The Delta Force must be a clean running hull. Most monos can not get enough bite with that prop.

We have two other 50mm props that are geared more toward the mono. The first is the 5077B/3

It has less transom lift and a little more blade area to provide a good hook up fo the monos, cats and tunnels. The next prop is the 5074C/3. this prop has even less lift, much more blade area and progressive pitch to provide the best possible hook up fo high drag monos. This prop will also provide excellent thrust in rough water conditions.

When your weather becomes hot this Summer you may also do well with the 4773A/3 or the 4773B/3. These props will hook up just a little easier the the 5083A/3 that you have tested and be a little easier to pull when you have less horsepower due to hot weather.

Good boating,

Andy
I was out running my sons Delta force today and hooked on the two props you recommended 4773A and 4773B

The 4773 A was a ok prop, good grip, quick launch and handling, but lack off the real high top speed. It was a ok all round prop.

Switched then to 4773B prop. I was not able to get the prop to hook at all. Only cavitated. I tried too toos it, give full throttle when launching. I even try to set the boat on water as it was idling.

For this application the prop is useless.

For now I have 3 propellers that are working, X450/3 pitch 3,8" I have the 4773A prop, and then I have the 5083 being the fastest prop over the two other. Launch is equal between the Octura and the 4773A. The 5083 need a little longer time to get a grip. The 5083 is an great prop when there are choppy water, and that leaves the Octura to be the best heat racing prop.
Rudi,

Thanks for the report!

super fast Sounds like the 5077B/3 may be the best prop for your set up.

The first batch of 4773B/# props are too thick on the leading edge and need to be sharpened better.

This will eliminate the cavitation.

I still think the 5077B will be the best all around 45 mono prop so far.
Today the test water was like mirror, temperature was in the mid 70,s and I was out to see if your recommendation was good.

I started out with the Octura to tune the engine as this is a easy prop to pull on calm water.

Boat was pretty fast and stable.

After some rounds I replaced the Octura with the 5077B/3 that I received some days ago.

I must admit that I am very impressed with the way you hit bulls eye as you said that this would be the best all round prop.

With the 5077B/3 the Delta force got a grip in only a few feet, and handling was great.

Top speed was way over the octura prop, yet boat was very stable.

I run the boat for nearly 15 minutes and after refueling a breeze came and made the water choppy (1-2 inch).

Now the combo came to life and the top sped was amazing. I also replaced the prop with a 5083, but this prop is to fast, and it makes me overstear the boat.

I have now the right prop for this boat/engine and don't need to test anymore. My son witch is 10 years old will compete here in Norway in the near future, and we are looking forward to show all the other com-peters the trouble end of the boat.

Thank you Andy for yous friendly services
 
Andy,I finally had a chance to run a 3857/4 on my Woodstuff 28/K&B SS Sport tunnel 1 deg neg. shaft angle, center of shaft 1/8" above the bottom of the sponsons. The boat would cavitate for about 50 ft. and hook up, make about 3/4 of a lap and quit. the boat ran well with a X437/3 and a M440. I flipped my Leecraft XTR-21 in the second heat and took out my steering servo arm, so I did not have a chance to run it on my Mac.

Next time at the pond I will try it on my Leecraft/Mac, and on my PT SS21 Sport Hydro. :)

Larry Conrad
Hmmmmm....3/4's of a lap! Next time you go out richen up the K&B and try it again.
I had a chance to run the 3857 again on my woodstuff on Monday. I richened up the needle a few clicks, and the boat ran well. The boat cavitates on launch but once it hooks up it stays hooked up, and comes off the corners strong.

Larry
 
Andy, what do you have for a CMB HR powered 40 sd3 mono? Im interested in a few of these props.
 
Andy, what do you have for a CMB HR powered 40 sd3 mono? Im interested in a few of these props.
Looks like the 5077B/3 or the 5074C/3 may be the ticket!

We've been getting reports of big speed gains form these two props compared to X450's on Vees and Cats.

All with good handeling.
 
Andy I sent you a PM but I will just ask here. I bought a new 3857/4 and just wonder if you think it will work on my Whiplash Sport 21 hull. Right now I am running a M445 with very nice results.
 
Andy I sent you a PM but I will just ask here. I bought a new 3857/4 and just wonder if you think it will work on my Whiplash Sport 21 hull. Right now I am running a M445 with very nice results.
So far the results on the Whip have not been good with the 3857. Too much lift unless your hull is a little tail heavy.
 
Ok no biggie, I will give it a try and see what happens. If it doesn't work let me know what prop I can try next.
 
Hi Andy,

Getting a little off the subject here, but how is your new line of motors coming? Outboards? :)

John
 
How much are these props? Andy do you have one that would be good on a old 44" Sightler with a O.S. 81 running sub surface?
 
How much are these props? Andy do you have one that would be good on a old 44" Sightler with a O.S. 81 running sub surface?
The 5074C/3 would be a good starting point if you are running a medium amount of nitro. They are $39.95
 
Andy I sent you a PM but I will just ask here. I bought a new 3857/4 and just wonder if you think it will work on my Whiplash Sport 21 hull. Right now I am running a M445 with very nice results.
So far the results on the Whip have not been good with the 3857. Too much lift unless your hull is a little tail heavy.
I'll have to agree with Andy on this one. I spent an entire day trying to get them to work with no luck. No matter what I did with the strut, it wouldn't carry the bow and jacked up the rear. 4 blades seem to have way too much lift. Try a small H4 on it too.

But on another note, if your Whip is electric, your balance and weight could be a bit different than mine was also. I ran a light Nitro boat.

Good luck and Happy boating :)
 
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Hey Andy, i know you have a lot of thing going on, but what is the status of the scale props. My 1/8 scale still isn't ready for testing , but it shouldn't be long.
 
Hey Andy, i know you have a lot of thing going on, but what is the status of the scale props. My 1/8 scale still isn't ready for testing , but it shouldn't be long.
I got the program made, but I did'nt get a chance to make a run of them. Should'nt be long be fore I can get back to them.
 
I have taken the liberty to sift through this post and compile all the comments about what is available and has worked best so far so one does not have to read all 18 pages to see what works best for them. A more detailed list will be available at CMDracing.com in the future. I hope this is helpful. It may also help us fill in the blanks for those of you that have tested props that are listed here but have no recommended hull style.

3457A/4 – Ready-To-Run 15. Hydroplane, .12 Riggers

3657A - .12 Outriggers

3857A/4 - .21 Sport Hydros, Vees, Cats and Tunnels

3861

3874/4 - .21 Rigger

3861A/4

4569/2 and 3 - .21 Outrigger

4576 - .21 Outriggers

4773/2 and 3 - .21 Riggers and .45 Tunnels (3 blade)

4773A/3 - .45 Mono

4773B - .21 Outrigger, .45 Mono

5074C - .45 Mono. Sport 40

5077B/3 - .45 Mono

5082/2 and 3

5083A – Sport 40., .45 Mono

5096C/3

6535B/3 - Gas Sport Hydro

6530C/3 - Gas Cat

6720C/3 - Gas Monos
 
Roger,

Who the heck took that picture of Prisilla? It's overexposed and that dumb boat is in the way :lol:

Off topic.....that new girl on the home page is absolutely gorgeous!

On topic.....waiting for a gas prop to be deliveried.

Off topic....you have a PM.

On topic......received the 5083AL/3 today. The quality is amazing! Can't wait for the gas prop I ordered.

If anybody in D-9 would like to rent it for next weeks race let me know :lol:

Glenn
 
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Andy, I am sure you have enough feedback on the props you have out and the input of someone pretty new to all this is probably not going to be that helpful...but figured I would throw my 2 cents in.

Spent Friday trying to find a tune on my mono before the Del City race this weekend. Your props showed up while I was up there testing and tuning. Got to the race Saturday and due to glare, they held off the start of the race and allowed us about 45 minutes of open water. I put your prop on, cut about an inch off the rudder...and threw it in.

I had been trying to get a tune (hull and engine) on a .45 speedmaster mono. I had a S/B x450/3 on it Friday (also tried 450 2 blade, and 452 2 blade). Nothing fancy about the props...just sharpened and balanced. I was having a problem with torque roll (boat wanted to lay on its right side when it was WOT), and being pretty uncontrollable when it was running WOT. After putting your 5077B prop on, the torque roll went away. Takes about 35 to 50 ft to hook up from the launch...but after it grabs, I had no problem.

Made the boat a lot more controllable...it will help me figure out the rest of the tune.

Have not had a chance to try the 5083A yet, but was going to try it on the mono too...

Boat=older version speedmaster mono with a .45 CMB HR engine in it.

Will be looking to buy another 5077B when you put them out in different metal (that is the plan right?)

Sean
 
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