1982 Pay 'N Pak Turbine

[Ray Sametz]

why do some fg hydros have that black on the sponson tips?

Carbon fiber for extra strength.

 

[Matt Smith]

Here are shots of my hull at Steve's shop (RC Boat Company). It's shipping today. The fun starts in a week....

Christmas in March for you Craig!

 

[Blackout]

I decided to fab a custom engine mount. The engine angle is 8.5 degrees. The hull is designed for floor fastened engine mounts. Notice the fuel tank on the right under the deck. Another goes on the left. Two 10 oz. tanks.

How much space is recommended between the carb and front bulk head? Thanks.

 

[Mike Cathey]

More than what you are showing in the photo.

I always try to leave 3 "minimum. I would begin by stacking all of your gear (*radio, cable, header, strut, strut shaft, prop, rudder, pipe, muffler, install the cowling and tape the wings on the back.in the boat and start checking the balance. Move the motor around until when you lift the hull under the deck at the sponson transoms it is down about 5 degrees at the tail. That should get you to a good starting point.

 

[Blackout]

Wow, 3 inches of space for air to enter smoothly into the carb? I know I asked the question, but it seems like a lot. Thanks for the info on balancing.

 

[Samuel Hagan JR]

Wow, 3 inches of space for air to enter smoothly into the carb? I know I asked the question, but it seems like a lot. Thanks for the info on balancing.

I have a 1" gap between the radio box and my carb on my scale and all is good.

 

[P THOMAS]

At least 1/2"clearance is what I have used setting up my boats if there is a radiobox or bulkhead infront of the motor. You can just cut out the front of the engine well for more clearance too, then you could move the motor forward more if the cowling allows, wouldnt the drivers cockpit be about where the motor is now?.

 

[Blackout]

At least 1/2"clearance is what I have used setting up my boats if there is a radiobox or bulkhead infront of the motor. You can just cut out the front of the engine well for more clearance too, then you could move the motor forward more if the cowling allows, wouldnt the drivers cockpit be about where the motor is now?.

Probably, but I haven't looked closely.

 

[Dasboatman]

Hey Craig,

Where do you plan on putting the radio box - forward of, or behind engine?

I don't have any scale that has three inches clearance in front of the carb intake. Try putting the flywheel start belt groove about where the rear sponson plate would cross the tub, then all tuned pipe to see where that will reside, radio box I believe will go forward of the engine in this position, but mock up a radio box with all the servos, switch battery pack, and see how the CG is as Mike suggested. Put the cowl on the hull to see if everything will clear. No benefit in adding lead to get the hull to balance to CG. CHEERS !!! Bob

 

[Blackout]

Hey Craig,

Where do you plan on putting the radio box - forward of, or behind engine?

I don't have any scale that has three inches clearance in front of the carb intake. Try putting the flywheel start belt groove about where the rear sponson plate would cross the tub, then all tuned pipe to see where that will reside, radio box I believe will go forward of the engine in this position, but mock up a radio box with all the servos, switch battery pack, and see how the CG is as Mike suggested. Put the cowl on the hull to see if everything will clear. No benefit in adding lead to get the hull to balance to CG. CHEERS !!! Bob

The plan was to put the radio box behind the engine. Probably mid ship. That's how Steve from RC Boat Company set his up from looking at video and pictures. He did not include any exact setup info. From what I have read, it's hard to get the CG too far froward on most scales, so I was just going to package everything as forward as possible and check balance before drilling holes for the engine. Has anyone had a scale where they could get the CG too far forward? Thanks guys.

 

[Dasboatman]

Hey Craig,

The preferences that boaters have for what they prefer varies so widely that most hull builders stay fairly generic. The Velasco hulls didn't come with any wood in them , some prefer rails, some prefer a bottom mounted engine mount as your using. Some prefer front radio box, others rear.

I have built a lot of 1/8th Scale boats over the years and have NEVER had one come out too heavy forward. In every case but one, I have ended up adding weight to achieve the CG I wanted. With the difference in lever arm lengths, it take a whole lot of weight forward to compensate for weight way back by the transom. I design and build my own WOF hulls, so I have a very good idea where everything will mount before I cut the first piece of ply. Have been running radio boxes to starboard of the engine in the center section, but outboard the tub since 1999. This set up works for the way I like to set up my hulls - fuel tanks forward in every case.

With the way Steve had recessed two 10 oz. fuel tanks outside the tub, you have plenty of options as to where to place your radio box. A removable box forward of the engine, maybe held in position with screws from underneath looks promising to me. That way you would have the entire tub aft of the engine free so you could play with many different tuned pipes, instead of going over a rear box and out the turbine tube. Putting the pipe down in the tub would also lower the center of gravity. Just some things to think about before you decide how to lay the hull out.

FYI Here are a couple pics of my Oberto. Initially built with radio box behind the engine and the tuned pipe exhausted through the rear of the cowl. Decide to move the box forward and open up the tub to play with pipes which I have been doing ever sense. I had to remove weight from the sponsons of Oberto to get the hull to balance to CG with the forward radio box. CHEERS !!! Bob

 

[Blackout]

Good info, thanks!

 

[Blackout]

I took a closer look last night and I think I will move the engine farther forward by cutting an opening in the fiberglass front bulkhead to make room for the carb. I might make a small radio box in front of the engine just for the RX battery pack, but then I would need to run a wire to the main radio box behind the engine. Not sure that is worth it as modern RX batteries are relatively light. Can a LiFe RX battery pack be made water resistant so that the small radio box doesn't need to be 100% water tight?

Looked into a front full radio box, but sure seems the engine would be too far back on this hull. My guess is that the engine is the heaviest component, so it makes sense to position that the farthest forward.

Thanks.

 

[Hydro Junkie]

Check this instruction book out and it should answer your questions:

http://manuals.hobbico.com/hca/lifesource-manual-v2.pdf

 

[Matt Smith]

Craig,

My Budweiser has a front and rear radio box, with a tube epoxied in between. My mixture and throttle servos, and battery are in the front, and receiver and rudder servo in the rear. I also have weight in the front as well. If you need any measurements let me know. Boat weighs in at 13lbs.

How's the ice on Stony Pond?

-Matt

 

[Blackout]

Craig,

My Budweiser has a front and rear radio box, with a tube epoxied in between. My mixture and throttle servos, and battery are in the front, and receiver and rudder servo in the rear. I also have weight in the front as well. If you need any measurements let me know. Boat weighs in at 13lbs.

How's the ice on Stony Pond?

-Matt

Thanks for the info Matt. Still ice on the pond.

Gonna be a little while still....

Edit: Actually, the ice is thinner than I thought.

 

[Matt Smith]

Nice. It was 65 here today. A lot of the ponds are thinning nicely. Budweiser is ready to go. Still waiting for the new rigger to be done at the paint shop. I am chomping at the bit to test this boat. Internal stinger turned out well. Going to try it without the prather muffler first, and if its loud I will put it on.

-Matt

 

[Blackout]

Just to confirm. For IMPBA, the drive dog has to be forward of the transom. No part of the drive dog can be behind the transom. Correct?

 

[P THOMAS]

Just to confirm. For IMPBA, the drive dog has to be forward of the transom. No part of the drive dog can be behind the transom. Correct?

Try looking up the scale rules on IMPBA. Generally if the real boat had the prop rear of the transom the model can too, which is the case for all the modern turbine boats. Best to get a picture but they can be hard to find. If you keep the strut under the boat I dont think anyone can complain about that with this paypak.

 

[Blackout]

I cut an area in the front to move the engine 1.5" farther forward and to mount the throttle and needle servo. Both servos are waterproof and will not be in a radio box.