JAE 45 Help

[Heywhire]

I am in the need of some help.

This is my 3rd project on my bench and hopefully will be the first completed in a long time.

I have started the JAE45 and need some advice on what to do. I have cut the pieces according to plans and assembled the tub with the assistance of a building board to make sure it was straight, and am building it with the "H" sponsons.

I have looked for some forums that would help me answer my questions but could not find any.

The questions I have are:

1- I am using 1/4" for the sides of the tub so do I need to add some more support in the middle?

2- I have seen on some posts of the .21 and .12 that the bottom forward portions of the sponsons and the tub extend past the ride plates, the plans dont show show this, should I do it?

3- What motor mounts?

4- What diameter stuffing tube?

5- What size flex-shaft?

I have attached photos of my project and welcome recommendations or criticism.

The 1/8" ride plates still have to be added and I have changed the radius on the top of the sponsons.

 

[Chris Wood]

well i am not the jae pro so i have limited info

what little i can help you with is the drive line

i would use a 3/16 cable. you can get a huey cable maybe one from andy brown and there are a few others out there. all are good cables

the drive line tube should be the main tube is a 9/32 that is glued into the boat.. then a 1/4 tube that goes inside that tube and goes inside the strut as well.

hope i helped

chris

 

[Speed Jr.]

1. 1/4" is plenty strong for tub sides

2. Yes, tailing edges of sponsons should overhang a bit

3. I went with traditional motormounts (Mount to walls)

4 and 5 Chris is right on......

Larry Jr.

 

[Heywhire]

Chris, this maybe stupid but the 9/32 that is glued in the boat, is this just for going through the bottom or the full length from flywheel to strut?

I see on the plans the engine center line but from the side view is the engine mounted parallel to the aft bottom of the tub or parallel to the bottom where it starts to angle up? Also, I read in a JAE gas build some got the kit from zipp kits along with the strut and the strut was manufactured with a 1.5 degree downward angle on it and it was done so because they had positive feed back from a speed record holder who set his up that way. Should the nitro boats be set up the same or do you think it was done just for gas rigger's?

Thanks all for the responses and help.

 

[Chris Wood]

the 9/32 tube will be glued in thru the bottom of the boat in the radio box.. it also goes thru the bulk head where the collet is on the motor.. then the 1/4" tube goes inside the 9/32 tube, make it flush or just stick out past the 9/32 tube in the motor area and put the strut on. bolt the strut to the transom and mark the end of the strut.

cut the tube off flush and your driveline is now complete

the reason for the tube inside a tube is if for some reason you have a problem with the tube you can replace it.. if something happens like the strut gets messed up you can pull the strut off. pull the tube out put a new one in and you are off and running..

VERY VERY VERY rarely does anything ever happend to the big tube that gets glued in.. most of the time if something does happen.. the boat is had a major crash or you have some other issue and it is all messed up.

hope i helped

chris

 

[Heywhire]

So I take it that the motor does get mounted at an angle because you would not be able to get the 1/4" inside the 9/32" too easily, correct?

 

[Speed Jr.]

Because the JAE calls for a slight S-Bend,you really cant do the 9/32 larger tube. Just put the 1/4 in and dont crash. lol! After what I have seen in my 21 JAE with the shaft wear, I think Rod Geraghty is spot on with the slight S-Bend.....So mount the motor flat. The 45 should run a flat strut, but again it only takes a washer on a Zipp style strut to at a bit of angle.

Jr.

 

[RickGlover]

Hey Haywire, Been running my 67 JAE for sbout a month now. Been working out my problems. Yes you need the overhang on the back of the spondson. Be sure and reinforce the turn fin sponson. I just completed another turn fin sponson after my other one shattered from the stress. With this one I put 1\4 on both sides. Then put dowels completely through the sponson. I through bolted through the the dowels with washers. I also 1\8 doweled down from top to the bottom of the sponson sides to hold everything together. The turnfin sponson is the weakest link. It must be strong are you will have alot of heart ache. Your build looks goood. You must have a good imagination to figure things out. You can put the two tubes in with the S bend. I did mine with no heating. Be sure you strut doesn't go inside your ski. Just the tube will be in the ski. That was a mistake I made. Having problems with hop in the turn because of it. Any question pm and I will try help you. Rick

 

[RickGlover]

The speedmaster univerall mount will fit. You may have to play with it to get it to work. But it will.

 

[Ron Zaker Jr]

So I take it that the motor does get mounted at an angle because you would not be able to get the 1/4" inside the 9/32" too easily, correct?

Your build looks great! I would not use 2 tubes for the driveline. The ski pretty much will protect the tube in the event of a crash.Slight angle on the engine mount is ok,do what is comfortable and allows for GRADUAL S BEND. Also get the strut as far down as possible. If that means notch the ski do it,if it means mill the bottom of the strut do that. I would consider extra support for the turn fin side rear boom tube(in the sponson).Our JAE boats are pulling serious forces in the turn.I have let the rear boom carbon rod go thru the outside of the sponson(flush),drilled,tapped and JB welded(long set) a 4-40 threaded rod in the carbon rod, and used a light weight flat washer with a locknut on the outside. NO FAILURE. Also consider pinning the tubes inside the tub. All it takes is one 2-56 screw going thru the brass and carbon,it won't slip at all.Hope that helps.

 

[Don Ferrette]

Because the JAE calls for a slight S-Bend,you really cant do the 9/32 larger tube.

Yes you can still do an S bend with a 9/32" liner. My Jag III twin is done that way and that's 5/16" going thru 11/32", it's even easier on 3/16" drivelines like 21's and 45's. Once you've annealed the stuffing tube and use a little WD40 as you go it's easy. Even when protected by a ski I still would rather have a separate glued in liner. Don't forget a flex cable failure can trash a stuffing tube as well.

 

[Ron Zaker Jr]

Because the JAE calls for a slight S-Bend,you really cant do the 9/32 larger tube.

Yes you can still do an S bend with a 9/32" liner. My Jag III twin is done that way and that's 5/16" going thru 11/32", it's even easier on 3/16" drivelines like 21's and 45's. Once you've annealed the stuffing tube and use a little WD40 as you go it's easy. Even when protected by a ski I still would rather have a separate glued in liner. Don't forget a flex cable failure can trash a stuffing tube as well.

Valid point on the cable failure,I agree.

 

[Speed Jr.]

Ron, you change your number? Ive been trying to get ahold of you!

Jr.

 

[Mike Hughes]

I aggree with the 2 tubes. Had several stuffing tubes that needed replacing from a failure of the cable. It is the only way to fly. Can be replace easily at the lake in between heats if needed. Not going to happen with the other method. Here is a trick I do keep it from rotating. Have the shaft log stub into the engine well at least 1/2". Then the stuffing tube as much is needed to reach the collet. Take a hose pipe clamp and place it around the log and tighten. It will clamp the log to the tube enough to keep from rotating. This works great with square drive setups.

Mike

 

[Heywhire]

Thanks all for the help..

 

[Heywhire]

One more quick question, If a .21 has about an 8oz tank should I double that since this is going to be a .45? I will be using a OS 46VX-M (brand new, not broken in) and would eventually like to start racing. I have never raced before just ran my boats at my son-in-laws dirt track that has a pond on it.

How do you calculate how much fuel you will need for a race, I am sure you don't want to have a full tank by the end of the race and you don't need to run out?

Thanks again for the help you all have replied with.

Ron, is this good for the pinning or do I need 2? I did not want to put holes too close together, I thought it would weaken the carbon tube.

 

[John Knight]

The standard tank size is about 12 oz and is what I have in both my 45 riggers. The tank size needed from a 21 to a 45 is not linear, meaning it does not use double the amt of fuel even if you double the engine size. The cylinder size is double, not the fuel used.

 

[Ron Zaker Jr]

One more quick question, If a .21 has about an 8oz tank should I double that since this is going to be a .45? I will be using a OS 46VX-M (brand new, not broken in) and would eventually like to start racing. I have never raced before just ran my boats at my son-in-laws dirt track that has a pond on it.

How do you calculate how much fuel you will need for a race, I am sure you don't want to have a full tank by the end of the race and you don't need to run out?

Thanks again for the help you all have replied with.

Ron, is this good for the pinning or do I need 2? I did not want to put holes too close together, I thought it would weaken the carbon tube.

that is the idea,but I use 2-56 very small and plenty strong.You can also make some little hooks attached to the pins to hold your tank in place(rubber band/o ring)

 

[David Meloni]

I'm watching this thread real close Heywhire. I'm building a .45 as well, but still in the gathering of hardware and funds stage.

Hope you don't mind me following your trail on this. Looks great by the way .

-Dave

 

[Alexander King]

I am waiting on the matereals to hit the door today or tomorrow I hope to build a 45 JAE also. What Motor mount are you going to use Heywire and David M ? I was looking at the CDMI motor mount but dont know the width of the mount.