|
RE: Unofficial
with both motors on 2S, the following applies the 2900 kv motor would be way slower than the 4450kv motor on 2S KV is a reference to the motor RPM per volt. so on 2S the 2900KV would max out at 24360 RPM, vs the 4450KV at 37380 RPM. the above examples are for a fully charged 2S (8.4V) the 2900 KV would be better on 3S and it would then have 36540 RPM and at a much greater torque. for a fully charged 3S (12.6v) if you wanted the 2900Kv motor, it should be run on 3S, not 2S. Jason.
Posted on: 9/11/2012 6:52 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11224910
RE: Unofficial
the higher C rate for the battery the better (especially so with boats). no harm can come from running even a high 100C + battery.
Posted on: 9/11/2012 4:56 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11224809
RE: Unofficial
cant help with the other problems, but how ,much water are you getting inside after a run ? i get 4-5 minutes per battery pack, and there is always a little water inside. maybe 30-50 ml. not heaps. so im not too bothered by it. i just tip it all out after each battery change. Jason.
Posted on: 9/3/2012 3:23 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11215356
RE: Unofficial
it doesn't matter which way you connect things with the water cooling system. you could connect the motor first or the esc. and you are correct, there's no In or out on the ESC. Jason.
Posted on: 9/2/2012 7:27 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11214369
RE: Unofficial
double post... Jason.
Posted on: 9/2/2012 6:54 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11214333
RE: Unofficial
the ESC wont "suck water" it has to be forced through by the action of the motor. on a regular boat, the water pick up is on the rear of the boat, and water is forced though as the boat moves forward. on the jet boat, the water inlet is on the rear of the jet unit. as water is expelled from the jet unit, some is diverted through the cooling system. there are plenty of pictures on this thread of the water pick up on the jet unit. Jason.
Posted on: 9/2/2012 6:52 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11214331
RE: Unofficial
[quote]ORIGINAL: seehuusen C rating is only for discharge, but most batteries will also have a charge rate written somewhere. If you don't have a charge rate, you should go with a 1C charge rate, so if you have a 3000mah battery, you can charge that at 3amps My Nanotech batteries allows a 5C charge rate, which my charger can't even do!!! (5C x 2.2A = 11amps) All other batteries I own are charged at 1C (although I have safely charged multiple times at 1.1C with no drama) Cheers Martin [/quote] that's spot on also. some of us have chargers that can handle up to 20A charge rates, so we can charge at those higher levels. as has been stated here, always follow the manufacturers recommended MAX C for charge rates. you can always charge slower, but NEVER higher. Jason.
Posted on: 7/29/2012 5:59 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11173857
RE: Unofficial
http://www.commonsenserc.com/page.php?page=c_ratings_explained.html here's a link that explains it. the c rating is dependant on the capacity of the pack. that's what the "C" stands for Capacity. so for example, when a battery says it can be charged at 1C it means that you can charge at the rate of the capacity of the pack. ie, 1C on a 5000 mah pack, means a charge rate of 5 amps. 1C on an 8000 mah pack means an 8 amp charge rate. the same logic applies to discharge rates. Jason.
Posted on: 7/29/2012 9:02 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11173301
RE: Unofficial
another thing to consider with C ratings... the C rating is referenced from the capacity of the battery. so a 2000mah 20C battery can handle 40000mah load (or 40A constant) while a 2500mah 20C battery will handle 50000mah load (or 50A constant) so the same C rating will vary depending on the capacity of the battery. some manufacturers are better at claiming genuine C rating than others. the higher C rating simply means that for a given load, the battery voltage will not sag under that load. Jason.
Posted on: 7/28/2012 8:25 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11172829
RE: Unofficial
that's the exact same motor i have in mine. on 2S, it will work well, but beyond about 75% throttle, it will just make more noise. i have the 35A Turnigy marine ESC in mine, and that's been faultless. im running on 2S 2200 nanotech battery with great results. Jason.
Posted on: 7/27/2012 8:17 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11171206
RE: Unofficial
i took the boat out for a run today at parramatta river. i took the opportunity to try running 2x2S packs in parallel to see how that would change things. as expected, run times were greatly increased. also the batteries didnt get as hot as with the single 2S packs, though there wasn't much difference in temps either way. the one thing i did notice was the boat was a heap more sluggish. not as fast top end, and lost prime much easier than usual. too much weight too far forward me thinks.... think ill stick to one pack in future, and just have more runs... i have 4x 2S 2200 nanotech 35C packs. each one gets me about 4 minutes. also noticed that im starting to get a little more water inside the hull after each run today. have to investigate where it's coming from..... jason.
Posted on: 7/15/2012 3:55 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11155773
RE: Unofficial
my boat weighs in at 520g battery at 134 i have the 4800kv motor and 35A turnigy marine ESC and i micro servo on the rudder. plus a traxxas water proof rx box. battery is a turnigy nanotech 2200 2S. [IMG]http://i101.photobucket.com/albums/m41/exaturbo/jet%20boat/IMG_1175.jpg[/IMG] [IMG]http://i101.photobucket.com/albums/m41/exaturbo/jet%20boat/IMG_1177.jpg[/IMG] Jason.
Posted on: 7/5/2012 4:19 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11143577
RE: Unofficial
That termination voltage is a settable function on my charger. It can and does balance properly at that level. The charger is a Hyperion EOS 0720I SD3. Quite a mouthful to say (and type) but it is the best charger I have ever brought. I may never need another charger. I usually run my lipos until the ESC kills the action. That's usually 3.3v per cell Haven't killed a battery yet. And that's in the boat and both cars plus a hovercraft. The HC is 2 years old and still going strong on the original 3S 1800 it came with. Jason.
Posted on: 6/1/2012 6:49 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11102339
RE: Unofficial
as Sundogz said, most all lipos can be charged at 1C very safely. the nanotech's im running in the boat say 8C max charge rate. that would be up to 17.6A , assuming your charger can go that high and mine can, i could theoretically charge a battery in about the same time it takes to drain it in the boat. i charged up a pair of 6S 8000 bricks tonight (max 4.5C charge rate on those) i "only" hit them with 2C (16A for these 8000 mah bricks) having a good charging solution is almost mandatory to protect your investment in the batteries. my charger can charge 2 packs at the same time, at up to 20A per Chanel. i usually don't charge at anywhere near the maximum rates though. just makes life for the batteries much easier. for the boat, i charge at 4C (8.8A) and for the bike i use 2C (16A). i also don't charge all the way to 4.2V per cell. i terminate the packs at 4.150V per cell. this should also give more life from the batteries. one last tip for long battery life. if you're not going to run them for a few weeks, charge to about 60%. not full charge. lipo batteries don't like being stored fully charged. store tham at around 60% and top off before the outting. Jason.
Posted on: 6/1/2012 5:25 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11102233
RE: Unofficial
for batteries, i run 2S 2200 Turnigy Nanotech 35C (70C burst) i get about 5 minutes run time, and the battery still gets kinda warm after a run. i have now bought a few more of them (4 in total now), and next time i take the boat out, im going to run 2 packs in paralel. that should help with run times, and make life easier on the batteries too. your ESC shoudl be programable for cut off. mine has an Auto lipo setting where it automatically detects the number of cells when the battery is first connected and then sets the cut off accordingly. when my esc cut's, i get half throtle so i can bring the boat back to shore no problems. im running the 35A Turnigy Seaking ESC
Posted on: 5/31/2012 4:17 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11100937
RE: Unofficial
only concern i might have is that the electric motors make 100% of available torque at zero rpm, where the nitro motor has to get to high RPM before it makes any real torque at all. this can be seen when a nitro tmaxx tries to pull an electric Emaxx. the nitro one has more power available, but by the time it has made any significant power, the electric one has pulled the nitro one very far backwards. you might find that the motor has a tendance to stall as soon as it starts to suck water through the impeller. some nitro boat owners that i know will even start the motor with the boat already in the water. others just kinda throw to boat into the water, so it's not as much load on the prop hitting the water. time will tell on how well this goes. i can't wait to see how this runs. it will be very interesting to see. Jason.
Posted on: 5/23/2012 3:28 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11091418
RE: Unofficial
can't answer the melting ABS question, but i wouldn't mind seeing a nitro powered one ! what size engine ? 15 ? 18 ? larger ? Jason.
Posted on: 5/13/2012 2:47 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11078773
RE: Unofficial
the paints that most people seem to be using are the tamiya PS paints. i certainly will once i have decided on a scheme. Jason.
Posted on: 4/10/2012 6:15 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11035817
RE: Unofficial
i love the Red Bull paint job. i still haven't decided on a scheme for my boat. i removed all of the original painted on decals, in preparation for a custom paint scheme, but so far it's still juts plain white. Jason.
Posted on: 4/9/2012 7:45 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11035365
RE: Unofficial
im running a 4800kv motor on 2S and it goes very well. Jason
Posted on: 4/2/2012 7:17 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11025910
RE: Unofficial
[quote]ORIGINAL: itsfishi i see your from sydney where do you run your jet boat,do you know any good spots im originally from sydney and am up there quite regularly. [/quote] there is a little man made lake not far from my place (about 10 minutes drive) that i run it at. im not exactly sure what it's called though. it's just off Henry Lawson drive at lansdowne, near the public RC car track. see the attached pic. the 1 arrow shows the lake, and the 2 shpows the RC car track. you can easily drive past the little lake and never see it (i did for years) i never knew it was there until a friend told me about it. [IMG]http://i101.photobucket.com/albums/m41/exaturbo/lake.jpg[/IMG] i also have plans to run it at parramatta park in the river. Jason.
Posted on: 2/9/2012 5:59 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10952012
RE: Unofficial
The Hyperion EOS 0720i SD3 that I have just bought can charge at up to 500w (20A) per Chanel. Obviously it needs an appropriate power supply to be able to do that rate though. Im still learning how to use it fully. it has 20 memories per channel too. And it can sync charge up to 14S battery packs. It wasn't cheap, but I'm happy with it. Jason.
Posted on: 2/9/2012 7:23 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10951206
RE: Unofficial
[quote]ORIGINAL: seehuusen Hey Jason, I got the charger in the post today, bloody awesome piece of equipment I reckon, cheers for the heads up :) (BTW, for fun to test it, charged the standard 700mah battery, took 27mins@1.4a, the battery is NOT 700mah as stated in the ad :P I'm not surpriced though hahaha) Cheers Martin [/quote] no probs. it's a great charger for the money. i used one for about a year until i recently took the plunge and bought a nice new Hyperion EOS 0720i Super Duo 3 charger and a 24V 41 Amp power supply. i can now charge my lipo's at up to 20A per chanel. (the charger is twin chanel) so i can now charge the batteries almost as fast as i can flatten them ! the nano tech's i use in the boat can handle up to 8C charge rate. i usually only hit them with 5C. so i can fully charge the 2200 2s in roughly 4 minutes, and charge two at once. i figure im now pretty much future proof as far as chargers go. probably never need to buy another one. Jason.
Posted on: 2/8/2012 6:17 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10949517
RE: Unofficial
been using the same radio for about a year now. there's a 200 page thread on the radio (and the mods that can be done to it) over on RCtech. im using the 4800kv motor that you mentioned. so far no issues with reliability. i think the failures have been from those running 3S with it. and i figure, if it does fail, it's cheap enough to replace. have ordered a bucket load of stuff from HobbyKing. (im in Sydney) though nothing from their NSW warehouse yet. i think they are still setting it up, and haven't got a huge range of stock yet. as for the steering servo, im using a micro in my boat, but as sundogz said, there are people that have had them fail. if mine does fail, im going to try a high torque micro servo with a metal gear train. Jason.
Posted on: 1/16/2012 6:02 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10912435
RE: Unofficial
@seehuusen im using the seaking 35A ESC in mine, and it's just about perfect. runs very cool. im running 2S with the 4800kv watercooled brushless motor. both the motor and esc are cool to the touch after a run. battery is a little warm though. im running turnigy nanotech 2200 2S packs in the boat. get about 5 minutes off each pack. i just got a few more of the same battery, and im going to try running two packs in parallel to give me longer run times, and better life on the batteries. running two packs should also help with keeping the battery cooler too. im running the same radio as the one that you bought. it's a great radio for the money. also, im using a traxxas slash waterproof receiver box for the RX in the boat. another thing. that charger that you linked to is going to be very very slow to charge the batteries. it will take just under 3 hours to charge one 2200 battery. so 3hrs charge time, for about 5-6 minutes run time. i would look at the accucell charger with a 5A power supply. plenty of them on ebay, and cheap enough too. they are a good entry level charger. you will be able to charge a 2200 battery in about 30 minutes. Jason.
Posted on: 1/16/2012 4:55 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10911191
RE: Unofficial
Hi all. thought i would post up the video of my maiden voyage. im fairly happy with the performance, a little dissapointed with the run time though. i only got about 4 minutes before the ESC cut to half throttle and the fun was over. im going to go buy a few more batteries so i can get a bit more run time. might look at paralleling 2 packs to double the run time. might just stick to the single packs to keep the weight down. boat handles great, no issue with picking up prime after loosing it (only lost prime a couple times when i spun out) specs are as follows. 4800KV brushles in-runner with water cooling jacket 35A Turnigy marine ESC, also water cooled brass sleeve mod on the jet drive Turnigy Nanotech 2200 2S battery. 35C , 70C burst both motor and ESC were cool to the touch after the run. the battery was fairly warm, but not so hot that you couldn't hold onto it. anyway, here's the video. i haven't painted the boat yet, still tying to work out what colour scheme i want to go with. [youtube]http://www.youtube.com/watch?v=EYq6pXUWAvc[/youtube] Jason.
Posted on: 12/11/2011 5:24 AM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10853945
RE: Unofficial
thanks for the confirmation on battery size. here's the pics. all stripped ready for paint. still unsure what scheme to go with.... [IMG]http://i101.photobucket.com/albums/m41/exaturbo/RC%20Jet%20Boat/IMG_1830.jpg[/IMG] [IMG]http://i101.photobucket.com/albums/m41/exaturbo/RC%20Jet%20Boat/IMG_1831.jpg[/IMG] plexiglass hatch mounted under the drivers to try to keep some of the H2o out..... [IMG]http://i101.photobucket.com/albums/m41/exaturbo/RC%20Jet%20Boat/IMG_1832.jpg[/IMG] [IMG]http://i101.photobucket.com/albums/m41/exaturbo/RC%20Jet%20Boat/IMG_1833.jpg[/IMG] [IMG]http://i101.photobucket.com/albums/m41/exaturbo/RC%20Jet%20Boat/IMG_1834.jpg[/IMG] and here's how the grill looks right now. thinking ill have to get something a little better ? i don't plan to run in very shallow water, so maybe this will be sufficient. i have no idea yet. [IMG]http://i101.photobucket.com/albums/m41/exaturbo/RC%20Jet%20Boat/IMG_1836.jpg[/IMG] Jason.
Posted on: 11/18/2011 8:39 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10818933
RE: Unofficial
hello everyone. first post here. i have wanted a rc jet boat for many years. stumbled upon this massive thread via Google, and i just HAD to get me one. i cheated somewhat though, and found a pre modified unit for sale on ebay. the boat has a water cooled 4800kv inrunner (im planning to run 2S with this boat) running the seaking 35A marine ESC. there has been some discussion as to what battery to run. would a 30C 7.4V 2800 pack be sufficient for this combo ? i will post up some pictures of the boat shortly. im in the process of removing the decals so i can paint it. it also has the brass sleeve mod already performed. only thing for me to do really is to put a more substantial grid on the water intake. can't wait to get this little boat wet ! Jason.
Posted on: 11/18/2011 7:05 PM by Author "Ratrunner"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10818825
| 
