Syncron build-newbie

[BHChieftain]

Day 10
Test run no. 1-- success!

All I can say is WOW! The boat is a rocket and stable.

Test run clip is below-- starts out a little slow as I adjust the trim and get used to the rudder input. Turns on a dime to the right (turn fin on that side). Left turns need to be at the right speed/input mix since there is no turn fin on that side due to the flood chamber-- I did one donut in the clip (kinda fun pushing the line on the left turns, and it is nice to know there is a flood chamber to bail you out).

Throttle picks up towards the end of the clip. She was bone dry at the end of the run. Lipos and ESC were cool, motor was warm to the touch but not hot (I didn't have a temp gauge).

http://www.youtube.com/user/BHChieftain#p/a/u/0/vRGOQbbNjAI

Next stop-- decals or paint, and probably a mount to get the ESC and UBEC off the floor.

-Chief

[tiqueman]

Very well done Chief.

[BHChieftain]

Day 11- Test run #2 and bad news...

I reported on Day 10 that the motor was warm-- the can itself was warm, but the rotor was very hot. Was advised that perhaps a bearing was at fault, or maybe the coupler was too close to the thrust bearing. I tried to move the coupler down while it was still in the boat, but it was very tight, so I decided to mess with that after the second test run.

Second test run was on a X440/3 prop, only did 3 minutes. Boat handled great, and nice speed. Brought her in to check the temps-- as before, the lipos and ESC were cool, the motor can was just warm, but again the rotor was hot, including the coupler. Decided to call it a day, and to take the motor out to pull down the coupler.

The coupler was locked into place, I could not remove it. Ended up trying to tap it off, and which point I pretty much ruined the motor... Even after ruining the bearings in the motor, I then tried to hammer the coupler off to save the thrust bearing (holding the coupler with pliers, and hitting the motor can), but it would not budge. So now I'm down a motor, a coupler, and a thrust bearing.

Given everything else in the boat was really cool, I suspect a bad bearing in the feigao.

I think I'll try a neu motor this time, and a different coupler design.

-Chief

[BakedMopar]

Before bangin on it you should of sprayed it with some penetrating oil. It probably heated up the shaft enough to where it expanded in the coupler. You could also try heating up the coupler. That kinda sucks. Sorry to hear especially when new bearings are less than $15.

[BHChieftain]

Before bangin on it you should of sprayed it with some penetrating oil. It probably heated up the shaft enough to where it expanded in the coupler. You could also try heating up the coupler. That kinda sucks. Sorry to hear especially when new bearings are less than $15.

Thanks for this tip! Just for kicks I took the destroyed motor and heated up the coupler over my gas burner for about 15 seconds and it came right off...

(this is why this is called the "syncron-NEWBIE" thread)

Hopefully I'll save somebody else from this mistake.

bye,
-Chief

[Rex R]

I like to give my motors a small drop of light oil on the bearings (new & old) before I start the season (about once a month after the season starts). quite likely the locktite 'glued' the coupler to the shaft.
I have been known to use a 'micro' torch (butane) to solder those blessed connectors...was a nice surpise to see how easy it was to solder 18ga w/ my 80w iron after doing 10ga, it went sooo fast :).
rex

[BHChieftain]

Here's the second test run at Kaiser Cove. Despite having only 1 turn fin for high speed right handers, it does turn to the left pretty well.

http://www.youtube.com/user/BHChieftain#p/a/u/1/rPzWiKcPDsU

-Chief

[tiqueman]

Looks great Chief! Sorry to hear about your mishap.

[BHChieftain]

Day 12

-Neu 1515 1.5Y (1500KV) motor arrived. Will will try an octura flex hex coupler with it. Wasn't sure if the flex drive cable was .130 or .150. I contacted Toysport, and they said the cable was .145. I plan to use the .150 coupler for it. If the cable is a tad too small I figure I can beef it up with some solder. Noticed there is hardly any front/back play with the rotor on the neu motor compared to the feigao...

-The neu motor drive shaft is a bit longer than the feigao, and there was too much space between the back of the coupler and the thrust bearing. Used a dremel tool cutting wheel to cut down the shaft-- all went well.

-With the new coupler, the flexdrive is about 1/8 inch too long, will cut it down tomorrow.

-Forgot to mention that a few days back I installed an antenna tube to get the lead of the 2.4ghz receiver out of the boat as high as possible for maximum range. Used another black faucet washer on the inside to waterproof it.

-Will try X637, X438, X440 props (X438 and X440 still on order). With the X637 there is about a 1/4" gap between the back of the prop and the prop nut. Need to figure out what's best to use to fill the space (ie, washers or a piece of brass tube).

-If all goes well we'll get a run in this Saturday to check out the new motor!

-Chief

[Steven Vaccaro]

The coupler should be fine. None of the .150 flex cable is really .150. The Octura stuff runs from about .145 to .148. Normally it falls about .147 or so. I also suggest soldering the end of the flex cable so it doesn't fry.

[Steven Vaccaro]

The coupler should be fine. None of the .150 flex cable is really .150. The Octura stuff runs from about .145 to .148. Normally it falls about .147 or so. I also suggest soldering the end of the flex cable so it doesn't fry.

[BHChieftain]

-I found a really small rubber grommet at the hardware store that fills the gap nicely.

-Just dodged another major problem--- my new neu motor has a larger diameter than the feigao, plus the cooling jacket is wider than the OSE cooling jacket used on the feigao. I was very worried the neu motor + jacket would not have enough ground clearance with the prexisting motor mount. Today I put the sleeve on the motor and installed it in the boat, and it just BARELY fits. I cannot even slide a business card between the bottom of the boat and the water jacket... but I can turn the jacket with the motor in place so I know there is some room... maybe 0.25mm or less... yikes, that was cutting it close!


-Chief

[BHChieftain]

Day 13- What a difference a prop makes

-Major modifications to the syncron. Added a neu 1515 1.5y 1500 KV motor, and changed to a flex hex .150 coupler. Needed to cut the neu shaft about 1/4 inch in order for the flex hex coupler to fit against the thrust bearing, and also needed to grind a flat spot for the coupler set screws.

-Even after cutting the neu rotor shaft, the flexdrive cable was still about 1/8 inch too long. Cut that down.

-The epoxy motor mount was not wide enough to accommodate the flex hex coupler-- used the dremel to widen the opening.

-The standard grub screws for the flex hex were too long-- found some smaller ones at the hardware store.

-Swapped out the hex nuts for the motor mount from M3 8mm to M3 10mm as the 8mm screws were a little too short.

-Did 3 test runs at Kaiser cove. The first prop was an X440. The boat hardly moved, massive cavitation. Changed to an X637, some improvement but still ran like a dog. For the 3rd run changed to the graupner 45 prop and it ran GREAT! It is amazing the difference in performance between various props. With the X440 and X637, even the sound of the boat was off. With the 45 prop, it was like a tuned instrument. After a 5 min run with the larger prop, EVERYTHING was cool-- lipos, ESC, motor casing, and also the motor rotor. The neu 1500KV really likes throwing a larger prop-- I'll try a graupner 48 next time, and also an X642. I really like the neu motor over the feigao-- runs nice and cool.

-Pics show the new motor and coupler, and the antenna mount.

-Video shows the performance difference between the 3 props.

http://www.youtube.com/user/BHChieftain#p/a/u/0/3WdC5Tqhues

-Chief

[BHChieftain]

Day 14

Ran a larger Graupner 48mm prop, best run to date (even better than an X642 that I had on loan), and everything remained cool even after an 8+ minute run. GPS at 38 and change... need to get 5mph more out of her to save face against Chris and his stock SV... will try an even larger prop next time, not sure when torque roll will kick in.



-Chief

[j.m.]

I think the 1.6" pitch props will be the way to go... It seems like you have power to spare.

try an x648 and see if you can't run that SV down!!!

Jon