Anyone and Everyone Chime in here

[mtbenjamin77]

For those of you running, or have run, 32"-33" Monos what was your total RTR weight with batts? The setup details don't matter just the weight.

[Drax21]

For those of you running, or have run, 32"-33" Monos what was your total RTR weight with batts? The setup details don't matter just the weight.

Mine is 3.4KG

[Foamaholic]

My Impulse 31, not quite 32", weighs 6.75 lbs.

[Rumdog]

Why?
Mine run better the heavier they are usually.
A lot of guys are always trying to cut weight. From my experience it is counter productive. I never actually have weighed a boat.

[Drax21]

Why?
Mine run better the heavier they are usually.
A lot of guys are always trying to cut weight. From my experience it is counter productive. I never actually have weighed a boat.

Yeah I agree. More weight lessens the chance of chime walking increasing the speed as long as the weight is central. Instead of riding waves you cut through them!

[mtbenjamin77]

Yeah I agree. More weight lessens the chance of chime walking increasing the speed as long as the weight is central. Instead of riding waves you cut through them!

I've found if you keep the longitudinal CG as close to the centerline of the boat and as low as possible the Chine walking is minimized without adding weight. I.E. use one battery in the center instead of two batteries on each side. Newtons law - forevery action there's an equal and opposite reaction. More downward momentum (mass x velocity) on one side causes reaction on the other side or chine walking. reduce the amount of momentum (less mass x velocity) = less reaction on the opposite side. Does that make any sense?

[mtbenjamin77]

My Impulse 31, not quite 32", weighs 6.75 lbs.

6.75lbs = 3.0617484975kg

Awesome! Thanks for the info and keep em coming

[Fluid]

...Does that make any sense?

It's a twisting of the physics. Putting the batteries along the centerline reduces the longitudinal polar moment, making it easier for chine walking to begin. But once it begins, having the batteries out on the chines makes the movement more difficult to stop due to the larger polar moment. I built two Aeromarine Titan 40s, one with the packs between the rails and the other out by the chines. Both worked well but when running the same speeds the one with the batts inside the rails starts chine walking sooner, but it also stops sooner. The lower placement between the rails helps straightaway running but can hurt turning; a higer CG helps hold the vee down in the turns while on some hulls a low CG keeps the hull more upright in turns. The real solution to chine walking is not the pack placement but the amount of hull in the water at speed. You cannot balance a triangle on one point.

For the rough windy conditions so common in Texas I add a pound of lead to my Titans. My latest is a full nitro layup and weighs almost 10 lbs. It runs mid-50s on 4S2P and wins District races.



.

[mtbenjamin77]

The lower placement between the rails helps straightaway running but can hurt turning; a higer CG helps hold the vee down in the turns while on some hulls a low CG keeps the hull more upright in turns.
.

It's always a give and take. I do find my mono setup as I stated above tends to hop in the corners on rough waters, but in the straights I'm leaving everyone in my wake. Of course I'm running with a bunch of cat hulls which don't corner too fast anyhow. I guess it falls back to driver preference.

[Brushless55]

My P-Spec DF33 is at 6lbs 7oz
and my P-Spec Carbon Fiber OM29 is at 4lbs 2oz
my DF33 is now becoming my P-Mono racer because of the extra weight over my OM29..

[mtbenjamin77]

Okay I am nearing completetion on my build and I weighed it in last night at 9lbs 6.6 oz with 9000 mah of batts. The batts weighed in at 3lbs 1.6oz leaving the boat it self at 6lbs 5oz. I'm not sure this thing is even gonna float

[T.S.Davis]

Darin and I were having this same conversation through emails about the triangle that is the bottom of the boat. Not the science. Just the gut feeling.

I think of the water to hull contact on each side of the keel as positive pressure points. If your going to run your boat high and dry it would need to be perfectly balanced left to right and also be nearly perfect aerodynamically so that even if it's completly out of the water it will fly straight and flat. Almost impossible with the equipment in the boat, turn fins, strakes, a bit of hook maybe in the bottom, a rudder off to one side. It's a lot of things to get perfect. So you need to compensate with positive pressure on each side of the keel. We do that by adjusting the strut height. How much pressure you need depends on the the boat. I don't have any math or science to back my thinking up. Just a feel thing.

I'm with Rummy on the weight too. I don't even consider it anymore. Except for spec sport. Might matter for OPC.

[mtbenjamin77]

Darin and I were having this same conversation through emails about the triangle that is the bottom of the boat. Not the science. Just the gut feeling.

I think of the water to hull contact on each side of the keel as positive pressure points. If your going to run your boat high and dry it would need to be perfectly balanced left to right and also be nearly perfect aerodynamically so that even if it's completly out of the water it will fly straight and flat. Almost impossible with the equipment in the boat, turn fins, strakes, a bit of hook maybe in the bottom, a rudder off to one side. It's a lot of things to get perfect. So you need to compensate with positive pressure on each side of the keel. We do that by adjusting the strut height. How much pressure you need depends on the the boat. I don't have any math or science to back my thinking up. Just a feel thing.

I'm with Rummy on the weight too. I don't even consider it anymore. Except for spec sport. Might matter for OPC.

I agree with your thoughts. I have a symmetrical mind. I see symmetry in everything so I tried to build this setup as symetrical as possible for just the reason stated above. every single item is placed along the centerline and every dual item is balanced side to side including the antenna. The only item I don't have balanced is the rudder but I just bought a second rudder to install if I decide I can't deal with the offset rudder design. The only other component that is bothers me is the prop. The only way to balance the prop is to have CR props but that is out of the question for this build. as far as weight I just use the weight to gage my wattage to weight ratio. This is one of my first FE builds so I'm learning here. I'll prolly figure out that alot of what I'm worried about really makes little to no difference, but that's okay with me.

[JIM MARCUM]

The only item I don't have balanced is the rudder but I just bought a second rudder to install if I decide I can't deal with the offset rudder design. The only other component that is bothers me is the prop.

Methinks you have OD-ed on symetry. Balanced antenna? They weigh next to NADA. Balanced rudders? Be more concerned about additional and unnecessary drag. Chill a little and just enjoy driving your boat. JIM

[T.S.Davis]

That's why I use a little water on each side of the keel. Makes all that other balancing act irrelevant.