Fire Fighter 45

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ok i said it wrong.... "S" bend or just one bend..... :p
Was already wondering what you meant with it. I'll give it a try once i got the engine in. Today i sealed the sponsons with epoxy, glued the top on the tub and made a new turnfin. Didn't like the other one, it was to thick because i couldn't apply enough pressure on it. Hopefully this is better, we'll see tomorrow. Added some new pictures to the gallery.
 
It's been a while since the last update. The rigger is finished and last weekend i raced it in the first race for the Dutch Championships. The rigger was for the second time in the water, but it ran superb. I won 4 of th 5 heats and took 1st place :D

I was a bit lucky with the starts, in the 3rd heat i crossed the line at 0,02 seconds after the start :p In the Netherlands we use the AMB transponder system. Every boat uses a transponder and the time/speed is measured by a computer. So never flase starts. Fasted lap was about 60 MPH in the 3rd heat. Heat times can be found here, this is the H7,5 class.

action_shot.JPG


finshed_rigger,_won_1_price_in_first_race.jpg


Video of the first heat can be found here (note file is about 70 MB): first heat

The last building pictures can be found in my gallery

Thanks a lot for all who helped me building the rigger and getting me all the parts (cowl, tank, engine, tape, prop, muffler ect) and most of all Tom for designing the fire fighter.

Because it was the first time in the water not much was changed on the setup. Current setup was:

- 1457 prop

- pipe at 10,25"

What it a good length for the pipe and what other props are worth trying?

(for those intersted, the first heat in offshore gas class can be found here (91 mb)
 
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I was a bit lucky with the starts, in the 3rd heat i crossed the line at 0,02 seconds after the start :p In the Netherlands we use the AMB transponder system. Every boat uses a transponder and the time/speed is measured by a computer. So never flase starts. Fasted lap was about 60 MPH in the 3rd heat. Heat times can be found here, this is the H7,5 class.
Boat looks good!

Just curous about how you're using the AMB system, we had it here in N. America in the mid 90's (I was the instigator) but got rid of it basically because it was considered too much trouble at the time.

I think I see the loop wires over the water at the starting line, how high up do you put them? Does everyone have their own personal transponder or are they given out at the beginning of a heat?

Is AMB still based in The Netherlands?

Oh, BTW, try a 1655 with a little cup and bring the pipe in 1/4" at a time until it gets "pipy" then bring it back out. How much (%) nitro are you running?
 
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I was a bit lucky with the starts, in the 3rd heat i crossed the line at 0,02 seconds after the start :p In the Netherlands we use the AMB transponder system. Every boat uses a transponder and the time/speed is measured by a computer. So never flase starts. Fasted lap was about 60 MPH in the 3rd heat. Heat times can be found here, this is the H7,5 class.
Boat looks good!

Just curous about how you're using the AMB system, we had it here in N. America in the mid 90's (I was the instigator) but got rid of it basically because it was considered too much trouble at the time.

I think I see the loop wires over the water at the starting line, how high up do you put them? Does everyone have their own personal transponder or are they given out at the beginning of a heat?

Is AMB still based in The Netherlands?

Oh, BTW, try a 1655 with a little cup and bring the pipe in 1/4" at a time until it gets "pipy" then bring it back out. How much (%) nitro are you running?
Terry.

for international races and now also for national races overhere, the transponders are compulsory. Everybody has to bring their own transponder and must be mounted in the boat. In the rigger i've mine mounted in the rc box, you can also mount them on the boat, they are fully water resistant.

This is what they look like now
AMB%20-%20AMBrc%20Direct%20Power%20-%20Transponder%20Large.jpg


The starting line is high enough so that big gasboats also can pass, although they sometimes when it is windy catch the line, you can see this also in our second heat for the offshore class at about 5 minutes (gas heat, 133mb)

I'll have a look at the 1655 and next time out i'll shorten the pipe. I'm was now using 35% nitro
 
Nice vid Paul, it's funny to see people smoking in the pits, we used to do that too!

Did they stop the race because the boat hit the wires? Does the system work well in general? What software are you using?

I know nitro is expensive there, but if you can increase to 50 or 60% you'll notice a difference. Also, if the 1655 is too much prop, you can "tongue" and "back" cut it like figures 2 & 3 here:

http://rcboat.com/prop.htm

You want it to look like the figure of the "14 series blade" at the bottom, personally I don't remove quite that much though. You'll also probably need a little "cup" in the tip as shown, otherwise it might hop... ;)

What pipe are you running?
 
Congrats on the first time out win Paul!I need to finish painting mine and get it wet.
Tim, thanks for the kind words. Looking forward to your rigger and hearing about the results. Post some pictures.

Terry, sorry for the late reply, i was away on a short holiday trip. The big cat hit the wires and then the race was temporarliy stopped. In the offshore class we have to run 8 minutes heats. Every race weekend consists of 4 heats. The guy with the most laps in 4 heats wins. After they fixed the wire, all the boats that where still running could restart in a "flying start" and run the last 5 minutes. For the offshore class the lines are just high enough, although i shorten up my antenna a bit so that I don't hit the wires. When it's windy hitting the wire is more frequently, the one on the movie was the only hit during the weekend. For riggers ect, the wire hangs high enough above the water.

I mix my own fuel so i'll mix some 50 or 60% fuel and see what happens. Nitro overhere is expensive, when you only by a liter (about a 1/4 gallon), it cost's about 19 euro (about 30 usd) A friend of mine has a lead to get it cheaper via a dragster racer.

I'll make the adjustments this week and hope to try it next week. I'll first try the stock 1655 and see how it runs, then will do the mods.

The pipe is a Andy Brown pipe but fitted with a extra muffler otherwise it's too loud for racing in the Netherlands. A friend of mine helped me with it and did all the aluminium soldering. Here is a picture of the added section

demper.jpg
 
Good stuff Paul, let us know how it goes.

That's a crazy price for nitro, about 4 times what it is here, if you can find it cheaper then go for the 60%, you'll see a difference.

That's a good pipe you're running, try it a little shorter...
 
Good stuff Paul, let us know how it goes.
That's a crazy price for nitro, about 4 times what it is here, if you can find it cheaper then go for the 60%, you'll see a difference.

That's a good pipe you're running, try it a little shorter...
Terry, i had a look in my propbox and appeared to have 2 1655 props, so i'm going to modify one anyway. I colored the area to remove on the prop, see the picture below. How much backcut would you recommend? This is about 1/8". The tongue removal is at the widest point about 1/4", what do you think?

Octura1655.jpg


Here is a picture of the old and new pipe with the extra muffler together in one picture:

AB_pipe,_old_and_new.jpg


Thanks for your help.
 
Followed Terry's instructions and modified the 1655 prop yesterday:

first modified the first blad (removing the black colored area), then put tape on the blade and used this as a mould for the other blade:

copy_the_blade.jpg


Started with the backcut and then removed the green colored part:

backcut.jpg


Here is the result, from left to right, stock1655, my modified 1655 and a props4u 1457:

stock_1655,_mod1655,_props4u_1457.jpg


Hope to test it this weekend, otherwise next week.

Another question, what is a good strut depth? Right now i put it on the table , setup the sponsons like the drawing and put the strut flat on the table? this way the centre of the propshaft is about at the same level as the bottom of the rear sponsons.

Terry Thanks so far for the instructions, i'll keep you posted on the progress.
 
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Props looks good! Let us know how they work out. If you can afford the 60% fuel you may want to try a 1657 like that (cut down with a little cup). Also, I find that heat-treating them helps them to hold their pitch better and keeps the edges sharp , did you ever try that?

Can you post a pic of the set-up instructions for the Firefighter?

Do you use AMB's software or someone elses?
 
Props looks good! Let us know how they work out. If you can afford the 60% fuel you may want to try a 1657 like that (cut down with a little cup). Also, I find that heat-treating them helps them to hold their pitch better and keeps the edges sharp , did you ever try that?
Can you post a pic of the set-up instructions for the Firefighter?

Do you use AMB's software or someone elses?
Hi Terry, i've read about heat-treating, but never done it, also don't have oven for it. I don't which software we use for the transponders. We have a race this weekend, 2nd race for the Dutch Championship, and i'll ask about the software. I think it's AMB software, will try to make a photo of the screen.

As for the setup instructions, i put the strut now so that the rear sponsons are 1/4" higher than the table surface, with that the top of the tub is parallel to table, that according to the buildingplan. Tom what strut setup do you use?
 
I've set mine up similar to my FF21, but haven't got the FF45 wet as yet. I have the tub set at 1 degree (lower at the front than the rear) The sponson tops (all 4) set to zero, and the rears 1/8" off the board and the strut flat on the board. Digital angle meter's make this job so easy!

I suspect I might have to adjust the strut depth / angle a little once I have it running, so I have enough provision to adjust it up or down from there.

Different props can affect the trim settings too. Test, test, test! Use a fixed course and a stopwatch!
 
You don't really need a kiln to heat treat props, a well known boater here named Gary Preusse told me the method he's been using for years and I can say it works very well.

This is for Octura BeCu (21C) props, not sure exactly what Jim is using at ABC.

Heat the prop as evenly as possible with a torch to a "dull orange" color, doing it in a dark room lets you see the color better. Quench it in water. The "standard" aging cycle is 625-650F for 3 hours, if you have a "self cleaning" oven it'll get that hot and work fine, plus the misses will be happy you cleaned the oven while you were at it. :lol: If yours isn't self-cleaning, crank it up as hot as it'll go and leave them in for 5 hrs. or so and they'll be almost as hard. I hang them from bent peices of wire but you could put them on a pie plate or something.

A trick I learned when finishing a new prop is to heat and quench it first, then sharpen and balance it before putting it in the oven, you'll get a better finish that way. ;)

Here's a link to some tech stuff:

<a href="http://www.brushwellman.com/alloy/tech_lit/AT0015_0295.pdf" target="_blank">http://www.brushwellman.com/alloy/tech_lit/AT0015_0295.pdf</a>

ps: If you could find out about the s/w and maybe take a pic. that'd be great...
 
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Here's a Roadrunner set-up from Marty Davis that works well on many other boats too:

http://rcboat.com/setup.htm

The pix don't show but you get the idea.

My 40 hydro is set-up with all 5 points on the table, strut flat, fronts are at 3*, then I add a 1/32" shim under the rear boom. It'll race without the shim but it's just a little too loose for my likeing... :rolleyes:

Do you have some sort of digital level?
 
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my tub is set like tim said. higher in the rear than the front. I also set my sponsons with 1 degree on the tops. So far it is working well but I've had carb problems to really give it a good testing. I believe my rears are 3/16" off the setup table.
 
my tub is set like tim said. higher in the rear than the front. I also set my sponsons with 1 degree on the tops. So far it is working well but I've had carb problems to really give it a good testing. I believe my rears are 3/16" off the setup table.
Terry, thanks for the setup sheet, i'll have a look at it.

Tom, i'm going to test this saturday and prepare for the race on sunday. The pond for sunday can be tricky, if wind is coming from the west as the forecast says, it means waves, so we'll see.
 
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