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hey guys running a bj 29 with the stock 1800kv motor with the stock 80a esc and turning a x642 s&b prop and have 2x 3s 5000mah 45c hyperions ive been running it on. my question is that if i switch over to high timing should i prop down to the x442 i have or can i stay with the x642? i have hit 125 degrees on the motor but that was after running it all day in mild chop and a few all out runs. also i will be repairing my old bj29 that split right down the left sponson seam so if anyone has some high quality epoxy resin for fiberglass and carbon please let me know. i just need enough to put a thin layer of cf on and laminate it
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What do you think High timing is going to do for you?"Our society strives to avoid any possibility of offending anyone except God.
Billy Graham -
well i bought a s&b m442 prop, a s&b x442 and x642. i guess ill use the x642 on low timing for chop days and small pond runs and the x442/m442 for all oout saw runs on high timing. am i right?Comment
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70+ mph on the stock motor and ESC? You're dreaming.'89 Hydrostream Vegas XT w/ Mercury 2.4 Bridgeport EFI - 240hp - 95mph
ProBoat Blackjack 29 - 58mph, Traxxas Villain, Traxxas Slash 4x4, Align T-Rex 450pro, Blade mSR, Blade mCPx, Dynam Cessna 182, Blitzworks F/A-18, UM P-51, UM SU-26XPComment
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The timing settings are more for motor efficiency. The stock motor likes low timing, high will just cause it to run hot and won't result in much speed difference. The only meaningful way to get more RPMs is either a higher KV motor or more lipo cells, but if you do that you should upgrade the ESC as well.
Also, these RTR hulls are not really strong enough to handle crashing at 70mph speeds. If you want to go the high speed route you need to reinforce the hulls. You might be better off keeping this boat as your fun 50mph sports boat and build a high speed boat from scratch with a hull designed for it. Other thing is high speed will greatly reduce runtimes-- you'll need to run 2P configs to keep runtimes in the 4+min range.
ChiefComment
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thanks for the info. i know running high timing on a 6 pole motor is kinda pointless but i was mainly asking because i have 2 super edf 1900kv 3659 motors and a 130a HV seaking waiting to be installed. also i understand that these hulls weren't meant for the beating im putting them through which is why i now have one bj set up for the 50 mph zone and i have another bj in the works that cracked a few weeks back at the seam. i epoxied the seam inside and out, sanded and layered 2 medium thickness strips of fiberglass over the seams on both sides. now i am in the process of laying carbon kevlar down as much of the hull as i can reach and glassing it where i will be setting my electronics. i might even pour a little expanding foam down in the tips to keep everything rigid. like i said i have one bj that is just for fun and now i want one thats all outComment
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Not really...the timing is dictated on the number of turns, number of poles and the type of winding (Wye or Delta).
I would start with low timing (0-5 deg) just in case and see how the boat runs. Advance to medium timing (5-15 deg), run the boat for a minute or so and check for higher temps. If it is a Y wind, then between 10 and 15 deg should work. The UL-1 is a 4 pole and works well at 11.25 deg.Comment
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i ran the x442 today on low timing with the strut slightly adjusted up and angled down slightly more, the bats still tucked up near the motor. i got a bunch of semi flat out runs but still managed 2 minor blow overs. bolth times landed right side up so i just ran it till the batts were starting to get low and brought it in. the motor was at about 145 ish inside the can, the batts were 125 deg F and esc was 83-84 F. so i just finished charging the bats (btw i installed EC5 batt connectors and 5.5 gold plated esc/motor bullet connectors) i also installed the m440 prop i had laying around that was already sharpened and balanced so ill leave the strut height and hope it compensates, if not then i shall have to dremmel out more of the strut slot to get a better angle and also try bending that tube more. its tough to bend that without feeling like im going to break the hull. any opinions/questionsComment
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i just found it weird how the x642 ran cooler than the x442, if the m44o works i might bump up to a m442 if i can find one lolComment
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Motor Timing and Efficiency
The efficiency of a DC brushless motor is dictated by its quality. A motor with higher efficiency is better designed and uses higher quality components (magnets, wire & etc.). The higher efficiency motor produces more power and less heat; an 85% efficient motor produces 85% power and 15% heat.
Timing does not determine efficiency (that’s built into the motor); but advancing the timing too far can produce excessive heat due to higher current draw. You can push a higher efficiency motor with higher timing, but eventually it too will over heat.I let the dogs out...Comment
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well the inevitable happened and my capacitors blew after running for 30 seconds 2 days ago but i was kinda wondering about running 6s with a built in bec to begin with. i had a sea king 130a HV esc so i threw that in the boat for now. i went ahead and dremeled more out of my strut so i could raise the prop and give it slightly more down angle. i had the batts even with the end of the trays and she was still bouncing a bit so i moved the batts up a hare and it helped a little but i think i still might need to raise the strut. my timing on the esc is 7.50 deg. and i am running a s&b m440. the motor temps are just over 130 after running for 3-5 mins and esc temps are just about 90 and the capps are at 120. that is also with double cooling i should add. i custom made a dual rudder set up with break away brackets so i could run separate cooling for motor and esc. what can i do to bring temps down further??? should i stick with the m440 or run my x442 with the strut higher? kinda stumped and need helpComment
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