Slingshot rear shoe placement

[Roxyflash]

Building a custom slingshot for cmb 27 engine.The instruction says inch on rear shoe should be 1/8 inch from touching the table when tub is parallel and front sponsons touching The front of shoe at 1/8 up on the tip.When Adam bought the boat there was a message to raise it 1/4.So if you set the strut to touch the table tub level the rear shoe should be 1/8 off table.

 

[Troy Hammons]

Between 1/8th and 3/16 depending what props you are going to run. Also if you have a way to measure the angle, the rears should be at 1.2 to 1.5 deg on the bottom last couple inches.

 

[Roxyflash]

Thanks not sure what prop it will be using.I’m going to build the kit and the one for the cmb will be a scratch built copying the kit this way if it don’t pan out the one for the kit will be setup for zenoah.I bought enough wood to build two scratch built if needed.

 

[Rich Jones]

Troy’s numbers are what I used. I installed the strut and the front sponsons and used my workbench that has an mdf top. I made sure I was getting a zero reading on the tabletop first with an angle finder. I then adjusted the strut until an angle finder read zero at about the front radio box bulkhead. I then used a piece of carbon plate as a spacer and put the rear sponson on this plate along with the angle finder and started shimming under the front of my spacer until it read between 1.2 and 1.5. Just for the heck of it I lightly traced around the rear shoe on the hull as a reference for when I glued. I spread epoxy on the inside of the rear sponson but left a thin perimeter with no epoxy. I did this so I could use CA to effectively hold the sponson in place until the epoxy cured. I didn’t have anyone to help so I had to get creative with getting them attached. This is basically the process Mario followed on his build as well. It worked pretty well. The boat runs and handles real well.

 

[Roxyflash]

Thanks for posting this.The ride strip is it a 1/8 thick piece there’s no reference for it.

 

[Rich Jones]

The ride strips are 1/8 on both the rear and the front sponsons.

 

[John Forbes]

Thanks for posting this.The ride strip is it a 1/8 thick piece there’s no reference for it.

Hi I was going to build a outrigger for this season 2024 does anyone have a slingshot plan,s that the can share with me so I can build my own outrigger. Ty

 

[Roxyflash]

Have to buy the kit as far as I know.

 

[John Forbes]

Have to buy the kit as far as I know.

I am a wood worker mostly everything I build are from plans. I wounder if I can buy just the plans.

 

[Mike Hughes]

I am a wood worker mostly everything I build are from plans. I wounder if I can buy just the plans.

https://www.blazermarine.com/index.php?l=product_detail&p=115The above link is to the plans. Plans come with pre lazer cut plywood templates. You can trace these and make your own. The bonus about these templates is they also can be use to build the boat.
Mike

 

[Lay26]

In my humble opinion it not a good idea to glue the rear sponsons on ....suppose you want to adjust or try something else...u have no adjustability....I've found that u gotta give yourself some room to play with... if u want to try a non wood carbon fiber version hit me up....it ran well at the nats....the driver needed some work.lol

 

[Rich Jones]

In my humble opinion it not a good idea to glue the rear sponsons on ....suppose you want to adjust or try something else...u have no adjustability....I've found that u gotta give yourself some room to play with... if u want to try a non wood carbon fiber version hit me up....it ran well at the nats....the driver needed some work.lol

I agree with you and I struggled with the decision. But I trusted what was working for others in the club and just glued them on. If I build another, I may try it the other way and play around with positioning.

 

[Lay26]

You going to ask so how do I mount the rears. .I use a 3m double side trim mounting tape from Napa auto parts....I don't know what it is but this specific one hold way better than the one from home depot....u have to take a fishing line and drag it between the tub and the sponson just to get it off...it's that agressive....i run the boat fist and set it the way I like and then maybe think about gluing the rears....I had 4 slingshots and only 1 had the rears glued on...it was one of the first ones I did...now I have larger rear to try...good thing the others aren't glued on

 

[Lay26]

Rich everyone sets up the boat the exact same way? Same prop, motor, pipe, drive, everything???? And share all the numbers? Wow...that's awsome

 

[Rich Jones]

Rich everyone sets up the boat the exact same way? Same prop, motor, pipe, drive, everything???? And share all the numbers? Wow...that's awsome

Not exactly per se. But I was ok with going this route for this particular boat. I followed pretty closely with what Mario did, since this was my first gas rigger. His boat runs really well and I wanted to follow suit. I understand the value of being able to adjust the rears and will likely try that on a future build. And I could always remove these and make them adjustable at some point. Yes, it would be a pain. Right now I’m not seeing the need, the boat is cornering well. I stick to one or two props that work particularly well and that’s about it. I’d be comfortable heat racing with this setup. I have some nitro boats I want to get going as well so I may be a little more focused on nitro next year but we will see.

 

[John Forbes]

You going to ask so how do I mount the rears. .I use a 3m double side trim mounting tape from Napa auto parts....I don't know what it is but this specific one hold way better than the one from home depot....u have to take a fishing line and drag it between the tub and the sponson just to get it off...it's that agressive....i run the boat fist and set it the way I like and then maybe think about gluing the rears....I had 4 slingshots and only 1 had the rears glued on...it was one of the first ones I did...now I have larger rear to try...good thing the others aren't glued on

Just woundering why are you guys changing them different that blazer org had on the plans. I was thing about getting one of these slingshot. Not sure now since alot of ppl are changing the boat not sure why?

 

[DON MAHER]

Everyone thinks they know how to build a better mouse trap!

 

[John Forbes]

Everyone thinks they know how to build a better mouse trap!

Is there a better option out there?

 

[Rich Jones]

Just woundering why are you guys changing them different that blazer org had on the plans. I was thing about getting one of these slingshot. Not sure now since alot of ppl are changing the boat not sure why?

It’s not changing the boat to adjust the rear sponsons. The front sponson angle is adjustable as designed in the kit. Leighton is just talking about being able to change the height and angle of the rears. It’s a matter of preference really. I think it’s a good idea to be honest, I just decided to glue them on. I built the kit pretty much as is and went with a height and angle that I knew was working. I added some carbon fiber plate in a couple areas for looks, but other than that, I stuck to the instructions.

This is a well designed boat and an enjoyable build. The Blazers support their products very well. Don’t let a little back and forth on the forum discourage you from pulling the trigger on one. Build it like the instructions say, it’ll be a good race boat . But people naturally make tweaks and like to share their success. And it’s common to trace parts and have something to be able to build another boat, repair crash damage, or make any other. changes you want to make, without buying another kit. Of course you can always contact Bob Blazer for any needed parts as well.

 

[Lay26]

John its not that there's a better option or else the mfg would have changed it. trust that they have tested this thing and its sorted out. the boat runs great straight from the mfg. I totally agree with Rich...build the boat that blazer build its a fast stable boat when built right. others just have different ideas they wanna try and if they are like me its just to satisfy curiosity. A BIG PLUS is the support from Bob Blazer he answers questions and gets the parts out fast as you need them and builds the boat too...you would be hard pressed to find that kind of support...don't get me wrong others mfg's do it, but when you have the support it makes a world of difference.