AJM45 coming along

[anthony_marquart]

Mine, is hopping per my front AOA is still too high... strut angle was just a test, too... mine is very very tight yet... and i cant keep the driveline in it.... but will shortly.... minor infractions i just have to push through is all... closer.... just... not in time... Mike...

You can shim the booms, at least the way I built mine, to bring it down pretty easily.

 

[RodneyPierce]

if the front AOA is too high, the boat would be loose on the water, not tight. Did you mean too low Mike?

 

[anthony_marquart]

That's what I was thinking also.. I'm very interested so see what the trouble is with Mikes boat. The shorts runs I had really did not show any of the ill traits that Mike is having to work on. But,.. it was short.. we will see.. I don't have the drawing here but I think with no shims the angle is 4.5 on the fronts.. maybe 1.5 - 2 on the back..

 

[RodneyPierce]

I think 1.5 * AOA on the ski is the ticket in the .45 boats. I havent had the chance to try it on a .21 yet, but I think it may be the ticket there as well.

 

[Mike Larson]

The rear booms are too high yet... whatever that is... started around 4.8 to 9, should be 4.4 to 5 currently... idk... ill measure it maybe tonight again... ski came in @ 2 or more... ill measure that too.... the driveline issue is the same everyone else attempting an s bend in a short after hull configuration is having, solved with an angled motor mount and a straight stuffing box install... two of my best props to the bottom... the strut was not right ( just a test angle), and that magnified the rear lift stupidity.... the platform is there... i just have had inccurring issues that can be solved by paying attention to detail.... like... flux... helps solder stick... and yadda.... hang tight... I'm working on it....

 

[RodneyPierce]

Dropping the rear boom tube will increase the AOA. Loosening the boat.

 

[user 6667]

Ran mine for the first time this evening.

Boat ran very well and stayed glued especially around the turns.

The boat turns on a dime and is very stable.

I have a ways to go on props.(running 1457 on the CMB 45 HR) and pipe setup.

The custom tank from Ryan works great.

The David Prusse turn fin worked awesome mounted all the way to the rear.

I'll get some pics up tomorrow.

 

[anthony_marquart]

Awesome.

 

[shoboat]

Jack,

You may want to try some 1655's on it!

Have Fun Testing,

Mark Sholund

 

[anthony_marquart]

Disastrous day, well not that bad.

I found that when my rudder is kicked back by a turtle it could come into contact with my prop.

Happened 2 times today. I will shorten the rudder bracket so it can't happen again. Trashed 2 nice props, scratched the rudder blade and trashed the rudder servo.

The rudder is a SM 21 standard and it's real long. I'm sure too long. In thinking ill cut it 2 in below the ski. Do you guys think that is long enough?

Before all that the boat was running very well getting to low 60s gurgling rich. Just started to lean it out and it was getting nice free of water. A few more bugs to eliminate and I think it will be great.

 

[user 6667]

Raced the boat Sunday in Open Hydro at Schaumburg.

There were a couple of twins and 40 riggers in the class.

The boat runs 'smooth' and turns extremely well.

It handled the rough water very well.

I have reduced the rudder length on mine already.

All I can say is 'WOW'..

 

[anthony_marquart]

Im really glad you like it Jack,.. lot's of effort went into the design and build!! how far below the ski did you cut the rudder?

 

[user 6667]

4 5/16" measured on the back side of the rudder

 

[anthony_marquart]

That is the full length? Thx

 

[user 6667]

yes. measured on the back side.

 

[anthony_marquart]

I did some very good testing over the weekend with this boat. I found that the props Mark S proposed were dead on,.. I was having trouble getting the boat up to speed. I made various changes but most were due to my own mistakes. The biggest change came when I raised the strut. The allowed the rear of the boat to settle a bit, allowing the fronts to rise and actually getting the boat looser on the water. I had a significant speed increase. At least 10 MPH over initial testing..

Quite sadly this was all before the boat hit the rocks and was destroyed. It's been a long time since I felt that badly.. took a long time to design, build and setup that boat.. a big loss for me.. Ill probably build another one this winter.. man that was a very hard, unexpected set back..

 

[shoboat]

Anthony,

What radio were you using?

2.4?

Thanks,

Mark Sholund

 

[anthony_marquart]

No,.. FM,.. I have a pre built JAE45 in the works Mark,..

 

[shoboat]

Anthony,

Do yourself a favor and buy yourself an early Christmas present?

Get a nice Futuba 2.4 three channel radio. Building and crashing

boats is not a lot of fun. So my propellers worked well for you?

Have Fun,

Mark Sholund

 

[anthony_marquart]

Here is a video of the boat before I made the changes,. I raised the strut after this run. Then I began running full laps down the lake. It crashed off to my left,. didn't make the turn,.. My boat is the last 1/3 of the video,..

Can anyone comment on RPMs? It was a bit higher after the boat loosened. looking forward to the JAE,.. I don't have time to build another AJM right now!!



The propellers worked GREAT,.. between that, the pipe setting, and lifting the strut a little.. It was flying..