6S FE RIGGER WEIGHT QUESTION ?

[derek owen]

working on my converted 45 size rigger conversion have got layout which gives me a ball park c of g as it was with nitro .. my concern is the weight of the tub! im using 2x 3s 6200mah lipos, the tub almost feels double the weight of my nitro tubs !!! not a heavy build but the motor . lipos and speed control are not light. should I be concerned ?

 

[RaceMechaniX]

Yes and no is the short answer. Weight will not affect the FE for launching but it may run wet as unless the speed is significantly higher with the FE setup as the sponson widths were designed for the nitro weight. I would typically also say you want to shift the CG back a bit and/or have more tail weight. This helps keep the front end lighter due to the extra mass and more tail weight helps keep the prop hooked up.

6200 mAh is a good battery capacity to run Q with.

What's perhaps the most important is how will the tub survive a crash and does it float without sponsons? Make sure to reinforce joints where you can and stuff foam in any available nook and cranny to ensure it can float. I have seen an awful lot of FE riggers sink due to no foam.

 

[BobBonahoom]

This is my first FE boat, so please forgive my ignorance. I have a question about weight.

I am building a Zipp 33FE as either a P or Q. As a Q, I am using a 2S and 3S 5,000, 70C in series and it is really heavy. I made the front sponsons wider (width of a 45 boat) anticipating some extra weight. But now with all the parts, the boat is approaching 8 lbs! My nitro 21s are a little under 4 lbs, so this is almost double that. Is this typical of FE?

 

[RaceMechaniX]

A 33 is better setup for Q with smaller cells (3000mAh) or just run it as a P boat with 4S 5000mAh cells. Weight is probably not such a big deal when running as the FE's have a fair amount of power, but if you crash that kind of weight will likely result in a catastrophe.

 

[HTV Boats]

Bob,
My 33 JAE with a 4074 motor and a 5000ma battery weighs in at 7 1/4 lbs.
I have two 39" Q_S hulls that hit the water between 8 and 9 1/2 lbs, depending on the batteries. My new 42" RR E-Max hits the water at at 7 lbs. As Tyler said don't get too hung up on nitro weight comparison as you have more power.
Mic

 

[BobBonahoom]

Thanks Tyler and Mic,

I'm guessing I should put foam in it everyplace I can. That actually reduces buoyancy, but may save the boat if it ever had a hole punched in it. Do you guys do that with foam?

 

[RaceMechaniX]

Bob, I pack every square inch with foam inside the boat for that exact reason. I purchase EVA foam from McMaster in sheets and cut strips and squares to fill the voids. It's available in different thicknesses and can be cut easily with a knife. McMaster-Carr

There are probably cheaper options, but the key is pack the tub full of foam.

 

[Grimracer]

I have a buddy.. Scratch Built a VERY nice 4S rigger.. nailed buoy one on the VERY FRIST PASS and lost a sponson.. the rest as they say is history.

That buddy.. Greg Hahn.. (very first run at Eagle Crest lake).. she is down there someplace!

yep.. it had floatation.. just not enough!


Grim

 

[DougSick]

I built a Q hydro out of an older model Eagle SG 40. With two 4000mah 6s, ESC and SSS motor, it comes in at 10 lb in running weight. Batteries are in the two front compartments and the motor is back where the radio box would normally be. CG is at the back edge of the turn fin. The Eagle runs very wet but stable in the chop.
I'm using the same 6s cells as my Q sport hydro which gets down to 30% after 7 laps.
It would definitely sink if it took on water. With the narrow hull, there is limited room to add the foam needed to keep it afloat. I have picked up some Eagle 67 sponsons which are twice the size and should keep it afloat. The boom spacing is really close so it may just need a minor mod to get them to fit.

 

[derek owen]

nearly finished weight is not too bad ! c of g will be just behind fin close on my nitro set up.. I am still packing in the blue foam where I can even up the rear ski !!