Mhz mystic 114 build

[BUMBLESPECIMOODA]

Cooling system water flow

Question for those in the know.

Will this boat's sponson-installed water pick-ups, create enough water flow while running alone?

Or will it need electric pumps to do it.

I ask because:

1. Simple is good. less electronic-systems to go wrong.
2. TSC micro pumps are fricken expensive.
3. I got the OSE water pumps. But they are huge and bulky, and don't know if I sould run one with t-fittings, or two, one for each motor/esc (weight is adding up).

Movement induced water flow if it works, will solve a lot of my questions.

[PlayerUnknown069]

Question for those in the know.

Will this boat's sponson-installed water pick-ups, create enough water flow while running alone?

Or will it need electric pumps to do it.

I ask because:

1. Simple is good. less electronic-systems to go wrong.
2. TSC micro pumps are fricken expensive.
3. I got the OSE water pumps. But they are huge and bulky, and don't know if I sould run one with t-fittings, or two, one for each motor/esc (weight is adding up).

Movement induced water flow if it works, will solve a lot of my questions.

Bubble, I high suggest against water pumps as they are another point of failure and added weight. Water pumps are only good for cooling at a standstill. Forced cooling is by far superior in my opinion. The XLX2 run very cool to start so heat concerns are primary the motor.

On my Mystic 114 I am running 2 Blade custom 1.8x3.25 props made by Dasboata. The boat ran slightly wet and did 96mph back to back. I ran the boat as follow:
Large oval Loop at 30-50% throttle to warm the battery
Full trigger pull for several seconds
large Oval Loop to cool down.

I did this until my batteries hit 3.7-3.8. The XLX2 were cool warm to the touch, 98-100 degrees F. My hand could stay on them. The motors were warm as well at 100-110.

Again,pumps are only good for standing still between SAW runs but most do a 1 and done SAW run.

[PlayerUnknown069]

To add, I have 4 pickups. I run each motor and esc on its own loop to avoid difference in flow restrictions.

[BUMBLESPECIMOODA]

Thanx fellas. Forced cooling. I also will run a seperate pick-up (4 all together), for each device.

[fweasel]

My experience with 40+" twin cat cooling... I run the micro pumps on my SAW boats where the electronics run very hot and I need active cooling while the boat is stationary between passes. For my general builds, even fast ones, through hull pick-ups alone are sufficient assuming the props and electronics are sized appropriately. If you have the room, 4 pick-ups are great. If you don't, 2 pick-ups work fine too. Flow is key: drill out undersized hose barbs and use solid piping instead of long hose runs where possible. Don't use Y fittings.

[BUMBLESPECIMOODA]

Started the skins on the motor bulkheads. Will do 4-layers of 6oz. each side.

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One side done:

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[AURELIO]

Buon giorno, premetto che sono nuovo pertanto se sbaglio qualche cosa ditelo tranquillamente.
Premetto che mi diverto nel progettare ( replicare da foto) aerei ed imbarcazioni.
ho terminato in questi giorni lo scafo GEICO e lo realizzo in stampa 3d, ? la prima volta che mi cimento in questo progetto pertanto in merito agli accessori, motori ecc, non ho esperienza.
chiedo se qualcuno nel forum pu? darmi informazioni in merito.
Grazie

[BUMBLESPECIMOODA]

Buon giorno, premetto che sono nuovo pertanto se sbaglio qualche cosa ditelo tranquillamente.
Premetto che mi diverto nel progettare ( replicare da foto) aerei ed imbarcazioni.
ho terminato in questi giorni lo scafo GEICO e lo realizzo in stampa 3d, ? la prima volta che mi cimento in questo progetto pertanto in merito agli accessori, motori ecc, non ho esperienza.
chiedo se qualcuno nel forum pu? darmi informazioni in merito.
Grazie

I did the same as you. I just read about as much as I could about the hull I wanted, and averaged what equipement was needed, to fit it out. Feel free to use my choices of gear.

Cheers,

Io ho fatto come te. Ho letto il pi? possibile sullo scafo che volevo, e ho fatto una media dell'attrezzatura necessaria per allestirlo. Sentitevi liberi di usare le mie scelte di attrezzatura. Cin cin

[BUMBLESPECIMOODA]

Motor mounts done, and will be installed this week, along with the esc & battery mounts. These things are solid! I won't have to use the rear motor mounts at all. One less step...

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[fweasel]

They look pretty stout

[BUMBLESPECIMOODA]

Passage-ways installed in motor-mounts, for cooling hose and wiring. Carbon tubes bonded in, and will be sanded to shape tonight.

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Areas etched for the motor-mounts.

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ESC & battery trays bonded in.

IMG_3082.JPG

[BUMBLESPECIMOODA]

Got the motor-mounts in. Brazed the ends of the flex-shafts, and will monkey with installing the stuffing tubes this weekend.

80.JPG 81.JPG W.JPG

Got a sellection of props to work with (40, 42, 45, 48), when it's water time.

AA.JPG

I've read that adding the width of the flex-cable, to the length of the prop-shaft, to deal with "wind-up" of the cable. My flex-shafts are pretty short (4").

This wind-up, are there numbers, pecentages or calculations that show how much the cable does this, over the lengths of cable?

[Dirk Jan]

I've never seen such neat and thorough carbon work on an rc boat, excellent! Very interesting to see.
I don't know about calculations on flex shaft tolerance, but I keep about 2mm free on my G-Force twin, which also runs short flex shafts.

Verstuurd vanaf mijn SM-S911B met Tapatalk

[fweasel]

I run about 3mm gap between the drive dog and end of the drives. You can gain a few more mm in length by slipping your collet on the motor shaft a little more aft.

[BUMBLESPECIMOODA]

I've never seen such neat and thorough carbon work on an rc boat, excellent! Very interesting to see.
I don't know about calculations on flex shaft tolerance, but I keep about 2mm free on my G-Force twin, which also runs short flex shafts.

Verstuurd vanaf mijn SM-S911B met Tapatalk

A wee gap it is.

This build and other recent carbon muckings, have taught me the rule of hubris (again). I'm not as precise and clean as I was 15-20-ish years ago. This Mystic boat has definately been a challenge.

I can't replicate this level of composite wizardry any more:

6.jpg 8.jpg 9.jpg 2.jpg 7.jpg

1-layer laminate, perfect on inside and out, with no gap in the cloth's weave. Resin percentage measured to the drop. That's when I could "Hand lay-up".

I run about 3mm gap between the drive dog and end of the drives. You can gain a few more mm in length by slipping your collet on the motor shaft a little more aft.

More wee gap it will be.