Rigger "Rule of thumb"

[dwilfong]

get a digital level it will make setup much easer and more precise.

http://www.craftsman.com/craftsman-digital-torpedo-level/p-00948295000P?vName=Hand+Tools&cName=Marking+%26+Measuring&prdNo=1&blockNo=1&blockType=L1

 

[Tony Jacuzzi]

get a digital level it will make setup much easer and more precise.

http://www.craftsman...=1&blockType=L1

david I have had and used a digital level for quite a while but thanks for the input

 

[Tony Jacuzzi]

Tony,

Terry probably has the right solution with AOA. If the bottom of the boat slopes up as it goes rearward you can't just measure the strut depth at the transom or you may be at a positive angle of attack. I have a boat that looks very similar and the bottom is flat, but it is actually sloped upward as it goes back from the front sponsons.

The only way to get the AOA right is to take off the turn fin, put the boat on a table, measure from the table to the bottom of the boat right where the trailing edge of the sponsons hit the table, then measure again about 6 inches rear of that measurement. Make sure they are the same measurement by putting a block under the transom. Now, go to the transom and look at the strut. it is most likely dangling in the air above the table. Bring it down to meet the table, measure the distance from the table to the underside of the transom.. Then, make the strut 1/8 inch deeper. Then loosen the strut enogh to make it moveable but snug, place a 3/8th block under the strut. set the angle of the strut flat on the block without changing the depth. Tighten the strut. Take out the block and rest the strut to the table. You will have a slight negative angle of attack and the strut height should be perfect for heat racing.

Terry.....while the 1667 is the best nitro prop ever, the low rpm of the gas engines work better with the 2916 and 2918 props. My gas rigger, probably the same design as Tony's runs 78 mph in heat racing trim with those two props. SE or RE should not be a problem when the boat is set up as described.

Let me know what you get on the measurements.

John

Thanks John I will keep in touch as I put it back together can you send me your email address [email protected]

 

[dave roach]

Tony

I would set it up like the Blackjack.Set the AOA and then put 1/8 shim under the rear sponsons and drop the strut to touch the table with 2 deg in it and try that.

Dave

 

[Tony Jacuzzi]

This is probably a well known fact (but I dont know it) I was wondering if there is a basic rule of thumb for balancing the weight on a rigger, or does it just not matter where the weight is positioned in boat. I have heard mention of strut weight etc. but really dont know much about it. Thanks tony J.

Tony I have been thinking about buying one of the Super Long Euro Tuned quite pipes and just tig welding my boom tubes onto the pipe., And just hang a engine out front?? Dam those are some long pipes.

Joe you made me laugh, and that Gas Engine weighs a ton too !!!

 

[Ron Olson]

Tony, I'm wondering what you have under the cowl as most of the RE engines that I've seen or have use square cooling jackets, The RCMK, JG or Quick-Draw. The pipe looks like one from CC-Racing, like the one on your mono.

My latest 'rigger, the Warlock which you haven't seen yet bounced badly. I found the AOA to be a mile off and the turn fin wasn't level. Adjusting both of them made a huge difference in the handling.

 

[Tony Jacuzzi]

Tony, I'm wondering what you have under the cowl as most of the RE engines that I've seen or have use square cooling jackets, The RCMK, JG or Quick-Draw. The pipe looks like one from CC-Racing, like the one on your mono.

My latest 'rigger, the Warlock which you haven't seen yet bounced badly. I found the AOA to be a mile off and the turn fin wasn't level. Adjusting both of them made a huge difference in the handling.

M&D cast cylinder rotated and mounted on an RCMK RZ bottom end

 

[Aaron Lavigne]

Its a RE gas rigger and it is wicked loose at 3.4 degrees AoA. I want to heat race it but that would be impossible at this time, its fast but has a poor running attitude for sure, I was really wondering if the rear exhaust and all the weight being directly behind the engine was throwing off the original engine location (built for SE.) because of the weight distribution I intend on lowering the AoA to 3.0 and see if I can still launch it but I have to mod the tub a bit etc.

If the engine is mounted rear of the front sponsons it is probably sponson dancing. Is that what it is doing?

yea my gas rigger is sponson dancing and gets a lot of air with the sponsons blowing upward... I have built mine similar style to the cmd rigger. It has the top of the tub parallel to water line, the tub bottom at the sponson planing surface 1" from the water line and 1-1/8" at the transom. The front sponsons have 4 degree planing angle and dihedral. The two rear skis have 2 degree planing angle. With a 2617 prop centerline 3/8" above water line and slight negative angle..the boat is way too flighty and taps it sponsons like a chine walk. Please help...not sure if its a cg issue or turn fin issue. The turn fin curve is parallel to water line at setup table

 

[David Murany]

I would suggest putting the boat on a flat table with put the turn fin and rudder and push the strut down until it's flat on the table with a piece of 3 2nd plywood under the front and try it. That is how Andy sets up the older SGX boats.

 

[Bob Morton]

Great information from some great racers. Now we need some feed back. Have a great day ya all

Nails

 

[Aaron Lavigne]

I would suggest putting the boat on a flat table with put the turn fin and rudder and push the strut down until it's flat on the table with a piece of 3 2nd plywood under the front and try it. That is how Andy sets up the older SGX boats.

So you are saying the bottom of the strut should be at the waterline with some negative angle?

I am also wondering if the modified 260 is too much for this hull. The sponsons are 20 inches long and the tub is 41 inches long. The sponson noses are 1/4" a head of the tub and they plane at 14 inches back from the tip.

I know the new gas riggers are 43" long but how long are the sponsons and where do they plane? I think I might have a cg issue or something too but I will try to drop the strut real low

Also wondering if having the tops of the sponsons parallel with the waterline on the setup table is ok? Maybe the tops of the sponsons should be angled downwards towards the front tip? But that would still be with 3-4 planing angle.

 

[David Murany]

Parallel to the table is good for the front sponson tops to start. Definitely try the strut adjustment. That may be all you need. We setup all of our boats this way even though they are nitro it should still be good for your boat.

 

[Aaron Lavigne]

I am going to try to lower the strut and see what happens. I thought it would have been too low but I guess not! We'll see Thanks for the info.

I may want to experiment with a longer rigger with longer sponsons, or maybe just extending the planing surface of the sponsons reward towards the center of gravity

 

[Jim Caldwell]

Drop the strut first that will give you more prop lift and raise the rear more.