Well, I've taken a bit of a turn in technology for Johnston. The brushless drive motors have been discarded because of cheap wire used in construction. Had the wires snap multiple times down near the windings, and multiple repairs failed to bring them back to life. So, switching to brushed technology for this boat. Going to use two motors direct drive off one ESC for the drive. Also, I'm replacing the brushless pump with a smaller printed pump with a brushed motor. Performance is similar to the brushless pump, but with great weight savings in both pump size and the elimination of a ESC.
I kind of wondered about having the windings that open in the boat anyways. I'm probably going to try the park 300 series of brushless motors. The motor wires on those come through the casing so hopefully won't jiggle around enough to break because of handling.
Have you picked your brushed motors yet? If you're running 12v or better these look intriguing for a DD. Haven't tested them yet. http://www.ebay.com/itm/12V-DC-6000...856983?hash=item2a557c9f17:g:beIAAOSwnGJWTvkL
I had picked up a few of these to test. http://www.goldmine-elec-products.com/prodinfo.asp?number=G9332 They work great on 12v and I was planning on using them. I really like the massive bushing on the front of the ElecGold motor.
Not really. I tried looking on Johnson's website but couldn't find this exact motor. Based on similar motors they sell, I'd imagine it's somewhere around 6000 rpm's.
Here is a photo of the new pump. It's much smaller than the other one, put pumping capacity is very close.
congrats Caleb. nice to see what you can do with design and 3D. Looking forward to trying it myself. I would think that there must be a way to optimize the larger pump. it should be able to deliver 3-4 times the output of the smaller with the right shapes and motor. good luck.
If they work well for your Johnston I'll pickup some for the Moggy. My current motors are no longer available.
I hope they work well for you. Just so you know, I'm running 1in 25 pitch BC props. Speed is well in excess of 22 seconds.
Yes, I probably should be getting much more flow. The impeller is a very simple design. By adding more blades with a better angle I could probably get 1 1/4 gal easy. Just haven't had the time to play around with it.
Nice build so far Beaver, looks great!! I just love watching the builds progress on the little boats, and how the challenges are overcome. Makes me want to go dust off Uritski and figure out what obstacle it was that stopped the build last time. It's been so long I forgot.....
Thanks, Cannonman. These little boats are lots of fun, sometimes frustrating, but lots of fun. I'm looking forward to seeing progress on your Uritski. Beautiful work so far.
Thanks Johnston! Since I'm building her for fast gun she'll get just one gun, a half unit spurt gun plus a pump.
