First foray into Twins

[RaceMechaniX]

Gilbert,

I am running the M410K, however for small boats I run the M400 or even the smallest M200. The end letter just specifies the inlet and outlet orientation.

You do need to be careful and select the right voltage range. Do not buy a 3V pump and run at 5V. The best pairing is get a little step down voltage converter like the FPV racers use from Pololu and the correct pump voltage for the output of the regulator.

https://www.getfpv.com/5v-step-down-voltage-regulator.html

=Tyler

 

[Terry Keeley]

Why do you need a water pump?

 

[RaceMechaniX]

Mostly for post run cooling Terry or in the event the rigger thermal's (i.e. the speed controller shuts down to prevent catastrophic failure) during a race I should be able to let it cool till the race is over and bring it back to the beach under its own power.

It's really the motors that benefit the most from post cooling. The rotors in particular heat up due to the eddy currents and after a hard run. When the rotor stops and the boat stops, they loose all cooling. It usually does not help having 100+C windings directly outside of the rotor for cooling. So by continually cooling the motor, I pull heat out of the stator and indirectly cool the rotor by cooling the stator.

Did you know you GTI has an electric auxiliary water pump that runs after a hot shut down to specifically cool the turbo bearings and reduce oil coking? Same idea applied to the motor, but we are trying to reduce the peak temperatures in the windings (to increase the longevity as heat is the number 1 factor for varnish breaking down) and reduce the temp in the rotor (Neo has irreversible demagnetization effects at elevated temps).

-Tyler

 

[bzubee]

Tyler as always your boats are very impressive. Where is the cg going to be?

 

[RaceMechaniX]

Bill it should be right where the ESC compartment is. So about 4-6" behind the rear boom depending on what batteries go up front.

 

[Gilbert Pun]

Tyler, thanks again, the information is very useful.

I run 15S and 16S for my big monos, it is always the case of being automatic cut off in the middle of top speed, and burnt some nice ESCs at continuously running top speed. I have tried a couple bigger windshield pumps for cars but they are too big and heavy and use big power. I guess this small water pumps would be very helpful comparing to changing new ESCs and got the boats burnt the price is worth it.

Gilbert

 

[Glenn Quarles]

After a heat race do you leave the boat parked in the water for a bit to cool the motors before picking it up? This is very interesting!

GQ

 

[Terry Keeley]

Mostly for post run cooling Terry or in the event the rigger thermal's (i.e. the speed controller shuts down to prevent catastrophic failure) during a race I should be able to let it cool till the race is over and bring it back to the beach under its own power.

It's really the motors that benefit the most from post cooling. The rotors in particular heat up due to the eddy currents and after a hard run. When the rotor stops and the boat stops, they loose all cooling. It usually does not help having 100+C windings directly outside of the rotor for cooling. So by continually cooling the motor, I pull heat out of the stator and indirectly cool the rotor by cooling the stator.

Did you know you GTI has an electric auxiliary water pump that runs after a hot shut down to specifically cool the turbo bearings and reduce oil coking? Same idea applied to the motor, but we are trying to reduce the peak temperatures in the windings (to increase the longevity as heat is the number 1 factor for varnish breaking down) and reduce the temp in the rotor (Neo has irreversible demagnetization effects at elevated temps).

-Tyler

Didn't know that, googled it and learned, ah those German engineers.

It sounds like heat is the limiting factor for hot FE set ups, cool little pump!

 

[RaceMechaniX]

@Gilbert, Yeah these have been great pumps. If you are running big boats the M410 will be plenty. It provides a nice steady stream of cooling and it definitely helps protect against the meltdown if something gets too hot and stops working. Do note that these are simple centrifugal pumps and need to be primed in order to work. I just run mine inline with the normal cooing path. TCS also make geared pumps which can self prime like this one:

http://www.micropumps.co.uk/TCSMGD1000range.htm

and

http://www.micropumps.co.uk/TCSMG2000range.htm

@Glen, yes I do let them sit in the water for a minute or longer to cool after a run. Makes a really big difference.

@Terry, the batteries and motors are no longer the limiting fuse in the loop. The speed control is now the fuse and it is a fine line on how they function. Some ask like circuit breakers which you can easily reset, but others are like one time fuses that blow. For the ones that have the smarts to full back before they pop, they typically need to just cool down to reset.

-Tyler

 

[ALLAN YUEN]

Look Nice Are you plan to go Nats Namba 2018 at Texas ? or will go only SAW against to Martin Jr ?

 

[RaceMechaniX]

Hello Allan,

This will not be a SAW boat and probably not even a 2-lap boat since I have much lighter and faster boats for those events.

I intend on heat racing this either in "open" or T-Hydro. I am not sure which races I will be able to make this year, but the NAMBA Nats as well as the IMPBA FE Internats are both on my calendar.

-Tyler

 

[Gilbert Pun]

Would one water pump be sufficed for twin motors and ESCs ?

 

[RaceMechaniX]

Yeah, one M400 or M410 should provide enough cooling when the boat is stopped or running slow. Plumb it inline to use the pickup pressure to increase flow at higher speeds.

 

[BrianTooms]

I tried out my pre-cooling idea at the Nats in Vegas, a water bottle with a submersible USB water pump filled with ice and water. I let it circulate thru the motor for awhile before a heat and I was amazed the motor was still chilled after the race. Might be an idea for yours in combo with your post cooling.

Sent from my iPad using Tapatalk

 

[RaceMechaniX]

Hello Brian,

We used to pre cool for SAW runs, but the problem was condensation inside the ESC. Too much cooling led to water which would fault out the controllers. We also found that by the second or third pass the motor and controller were already getting too hot. The micro pump was the ticket to cool the components. It makes more improvement in time trials racing where you run and sit for a minute, but it also helps the heat racing boats after a hard race.

-Tyler

 

[john urbowicz]

Hello Brian,

We used to pre cool for SAW runs, but the problem was condensation inside the ESC. Too much cooling led to water which would fault out the controllers. We also found that by the second or third pass the motor and controller were already getting too hot. The micro pump was the ticket to cool the components. It makes more improvement in time trials racing where you run and sit for a minute, but it also helps the heat racing boats after a hard race.

-Tyler

nice build, tyler. how bout inviting a twin nitro to a challenge race? would be interesting???!!!!

 

[RaceMechaniX]

I am hoping some organizers open up the twin classes to all power systems.

 

[Tom Foley]

I don't think any of us piston pushers could touch that thing in acceleration !!! It's going to be the next big class I think !! You are leading the way !

 

[john urbowicz]

I don't think any of us piston pushers could touch that thing in acceleration !!! It's going to be the next big class I think !! You are leading the way !

tyler, are you going to get enough run time to run sanctioned races in Namba and Impba?

 

[Glenn Quarles]

Tyler, is it going to be ready for SpeedWeek?

GQ