T-Pain Is On A Boat: Re: [Electric Boats] Catalina 22, Torqeedo vs. Traxxis

Wednesday, June 12, 2013

Re: [Electric Boats] Catalina 22, Torqeedo vs. Traxxis

If you are up to experimenting with props, try a 10x6 APC pusher prop (about $4) meant for a model airplane. You will have to bore out the hub to fit your Traxxis shaft and machine in a slot for the shear pin (easy with a dremel and a tiny ball milling cutter).

You can't really do much prop experimentation without a way to measure current. The electric RC airplane world sells a "Whats UP" meter for about $60 that you can wire in to read up to 50 amps.

The heat is probably from cheapo connectors.

A fairing on the round tube will help too, even at 3 mph.

Denny Wolfe
wolfeboats.com

On 6/12/2013 12:33 PM, oak wrote:

This is VERY preliminary, and VERY approximate, and still somewhat oranges to grapefruit...

But some might find the information interesting.

I was able to get out yesterday and make a couple of brief experimental runs comparing a Torqeedo 4R, 48V system to a Minn-Kota Traxxis 80 24V trolling motor on a Catalina 22 (no sails, even the main sail and boom were not rigged - so this is the minimal wind resistance possible).

I'm running on a reasonably protected inland lake. No current. The primary concern from waves is that from other boat wake (which can be significant on this lake). "HIGH WIND" for this lake would be whitecaps (18-20), and is probably considered "nominal" by many...

The data I collected is on my web page at: https://sites.google.com/site/danrobertstx/home/sweet-pea/c22_electricpower

I hope to collect more data, and eventually be able to plot a couple of power / speed curves.

Bottom line:

Torqeedo 4R (48V)

===============

This motor has PLENTY of power for a Catalina 22. At full power (3300w), the motor easily pushed the boat at 6.5mph into a moderate wind. This is about as fast as a Catalina 22 is going to go. At moderate power (1500w), I could still achieve 5mph into a moderate wind.

The Torqeedo is "rated" for a max consumption of 4000w. At full throttle, with the lead batteries I was using, I only got 3300w - but that was still PLENTY for my purposes.

Minn-Kota Traxxis 80 (80# thrust trolling motor, 24V)

=====================================

While this motor could "push" the boat, and was definitely capable of getting me in and out of the marina for docking purposes, it maxed at at no more than 3.8mph, going downwind, in 10-15mph of wind - at full motor power (100%).

Max speed into an estimated 10-12mph wind was 3.4mph at 100% power. 75% power speed was about 3.4mph into a moderate wind.

It'll move, but it won't get you anywhere fast.

I ran the Traxxis for about 45 minutes, at various speeds. When I was done, the control head was HOT. No signs of failure, but I was a little concerned that it might not stand up to several hours of motoring.

The Traxxis has plenty of torque for a Catalina 22. It just seems to be lacking in speed. And this may be validation of the statements made previously that the trolling motor is designed to "troll", and is prop-pitch limited to slow speed.

Note that I couldn't measure real power consumption on the Traxxis. The literature indicates that for the Traxxis 80, one could expect to consume about 60A at 24V for full power, but there is no power display, and I didn't have anything hooked up to provide that info.

I'd be REALLY curious to put a Torqeedo prop on a Traxxis motor, and see what that would do!!

Bottom line -

The Traxxis would work fine as a inexpensive (~$550) "backup", but probably isn't sufficient for primary outboard use.

The Torqeedo is more than sufficient for the Catalina 22 for primary backup use - but providing lots of 48V power is an EXPENSIVE, and very HEAVY proposition.

John