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  1. #1
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    Which motor should I chose?

    I have a brand new Summit that I want to install brushless from day one. I have bought a Keshaw Design ver 2.2 Lipo 4s with the Leopard 150A ESC but I saw that the motor is rather small in circumference with 2 pole and so I am wondering if a 6 pole motor with a bigger cricumference would be better suited for the Summit?

    This is Kershaw system and I got the 8XL motor, the lipo 4s type 2075KV, 2 poles
    http://www.kershawdesigns.com/

    however while I liked the ESC, I think the motor may be lacking in torque, i think this motor may be better? 2560kv

    http://www.*********.com/*********/s...dProduct=14632

    It's a 6 poles motor and so should have more torque?

    Which one should I install in my Summit to have more torque?

  2. #2
    RC Racer
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    I just got the 120amp esc with the 2370 leopard and works well from the 2 days i have had it. It came with the leopard 36 series motor and a fan. Is this simlar to what up got? Have up run it much yet?
    dewalt 14.4

  3. #3
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    No my Summit is still stock, the idea is to go brushless from day one, but I wanted to know which motor is best for it? Anyone with experience on these two?

  4. #4
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    Does anyone have any experience with these two motors?

  5. #5
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    I have heard that Kershaw designs systems are good power on a budget, but for all out quality, performance, and censored for crawling a Tekin RX8 and T8 motor are the way to go.
    Brushless Summit!!!!!
    Slash 4x4

  6. #6
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    so mant BL motors to choose, how would the tekin run on stock batterys till i got the lipos?

  7. #7
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    I have to narrow down to a level of expenses that I am willing to spend and these two motors satisfy it well, the Tekin is a whole different kettle of fish in terms expenditure altogether.

    If someone has experience of these two motors, please chip in. I read that 6 poles is more torquey than 2 poles, and in my own thinking the larger diameter rotor of the ********* ********* motor can excert a better torpue momentum than the smaller Kershaw motor, that alone give it advantages in torque

  8. #8
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    Let me elaborate some more, first in terms of value for money these two motors are hard to beat, I am sure that the Tekim/Castle/OEM brand are much better motors but they also do cost a lot more, so for this post I only want to compare between the two chosen motors.
    I have received the Kershaw and it is very well made on the construction level, I have no indication of its efficiency nor torque, only that it is a 2075kv, the ********* on the other hand is on back order, meaning I can't physically examine it, but it seems that it has a larger and shorter can size, almost the exact size of the 775 Titan fitted to the Summit and so would look well fit in the Summit, the Kershaw is narrowed and longer but would also fit well on the Summit.

    Kershaw recommend a 12t pinion which seems to indicate to me that the motor may be slightly less torquey, the ********* is a 6 poles design and with the larger diameter should possess a better torque characteristic. I intend to use the stock 18t recovered from the 775 to fit on the Summit, the better torque of the motor should allow it to work with this gearing, now with the higher gearing AND the higher KV of 2560 should equate to a higher top end too?

    So it seems with the ********* you can have the same climbing ability plus a higher top speed (assuming the same lipo battery arrangement of 4s 6000mA 25C that I have ordered), in addition it should also run cooler negating the need for additional fan and resulting wastage in energy, both in direct heat AND the cooling fan.

    So it seems to me that the ********* is the better choice all round? IS that conclusion valid?

  9. #9
    RC Turnbuckle Jr.
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    Meh.

    7" tires
    2650kv
    4s lipo

    You can forget climbing or crawling, that's more like a flying setup really.

    If your intention is to go slow still but with more power, then you would be wanting something more like ~1600kv tops with 4s lipo and switch between 1st and 2nd gear to get a bit extra speed over more open ground.

    Regards torque, the ********* would be the better motor for sure- seems to be more like a 1/8 buggy or truggy sized motor ( bare in mind the length of the cooling fins which make it seem fatter than it really is - equal to the castle 1512 2650kv motor pretty much ), though it would work fine in an MT if the gearing was restricted somewhat. The massive tires and extra weight of the truck ( 13lb... ) will result in higher temps so lower gearing will be required to prevent motor, esc or lipo damage from excessive current draw. The 8XL ( 36x74mm ) used to be standard equipment that early BL pioneers would install on their converted trucks or upgraded Emaxxes many moons ago- still a nice cheap option for a BL setup these days but it isnt a motor designed for going slowly or pushing a heavy truck; I have 3 9XL corpses stuck to my fridge as testament to that.

    I would ask what you are really wanting to do with the truck, so that you can choose a more suited motor for how you will be driving; a high kv is not preferable, but a larger & lower kv motor would be for crawling and general use with a speed roughly equal to the truck in stock form.

    if you were planning on making the summit into something more like a BL emaxx or erevo in terms of speed, then the summit isnt the right truck- it's setup for a completely different purpose and doesnt handle speed very well, the complicated diff and tranny setup doesn't react well to having too much power put through them..
    Keeping the Mods busy is my specialty...

  10. #10
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    Thanks for an excellent reply, to the point. But even with a 2560KV motor, the low ratio gear should still climb around the same rate as the stock 775. no? I am not into rock climbing, nor massive 50mph+ speed either, but would like a truck that can go nice and slow without too much effort over rough forest floor (with climbing over obstacle found) and a ***** perhaps 35/40mph cruising over flat ground

  11. #11
    RC Turnbuckle Jr.
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    I think the 775 motor is roughly equivalent to a ~1600-1800kv BL motor ( the 550 titans are equal to ~1800kv , I know that much for sure and the 775 is a little slower than them ). The issue, or major catch really with BL motors is that they dont like being span at high rpms ( nearer to full throttle for extended periods ) without much load on them- very much the opposite of brushed motors. You could certainly gear down a high-ish kv motor to produce buckets of torque, but it would run very hot within a short space of time which would result in failure of the magnet/ rotor, and a cooked esc as a result ( the heat weakens the magnet > creates a higher kv effect > greater current draw > cooked esc and batts- nearly did that myself once; ~350*F isnt good for a motor, lol ).

    What would be preferable is an already powerful motor of a fair size ( 4-6 poles, ~70-80mm long & 36-44mm wide- L to XL size if you like ) with a lower kv rating, then you can gear that up to get a better speed and still make lots of torque by using the 1st & 2nd gear ratios to your advantage.

    One setup idea would be to use a 2000kv motor, gear it 18/68, then you get 20mph in 1st gear, and 30mph in 2nd gear ( the stock summit tires wont like much higher speeds really as they have so much side wall and are rather soft ). Or, with a 2200kv motor you get 21mph & 35mph respectively for 1st & 2nd gear which is pretty nice; you can just limit you throttle usage so you can still crawl effectively at lower speeds.

    40mph though is more like a BL emaxx / erevo setup with 4s lipo, the 2200kv castleneu motor & 18/58 or 24/65 gearing, not something the summit will handle very well as it is such a heavy and tall truck- you can certainly alter the suspension, ride height, tires etc to make it handle better, but it isnt an all-rounder type truck really, it it best at crawling & trail-riding and then has a bit more speed ( ~20mph ) for more open spaces, but it wont keep pace with a truck designed for higher speeds from the get-go...
    Keeping the Mods busy is my specialty...

  12. #12
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    From your reply I seems to deduct that Kershaw 8XL at 2075KV would be better suited to my use than the ********* 2650kv? Did you take into consideration the 6 poles construction of the ********* agaisnt the 2 poles of the Kershaw?

    Furthermore from what I gathered, for the Summit an upgrade via the Dewalt brushed motor would seems more fitting to the nature of the car, namely:

    1 - Waterproof (you answered this is in the other thread), inc the ESC simpler DC type (using the Traxxas stock waterproof ESC)
    2 - Load more torque in the Dewalt than brushless motor
    3 - Simpler installation

  13. #13
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    By the way I won't be using the stock tyres but would upgrade to another type, just as big but with less sidewall flex

  14. #14
    RC Turnbuckle Jr.
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    Hmm, tricky one. The feigao-type motors ( 2 pole construction ) are known for running hot regardless of how you gear them due to inferior construction and materials ( they are copies of a German motor brand called 'Hacker' ), so given the choice I;d take the ********* motor, but I would prefer a lower kv ideally; have a check on ebay for some hobbywing motors- the blue 2000kv 4274 motor & the blue 2250kv 4168 motor are both nice options and less than $90 each. There are also the Leopard branded motors which look like red/ black castleneu motors essentially, they have gotten a fairly good rep as cheap 4 pole motors and cost as little as ~$60 for something ideal:

    http://cgi.ebay.com/HOBBYWING-XERUN-...item2a0b26c60c

    http://cgi.ebay.com/HOBBYWING-2000KV...item3f04879cf3

    &

    http://cgi.ebay.com/leopard-BM-4065-...item588daa5d22

    http://cgi.ebay.com/LEOPARD-Boat-367...item5ae07ad93c

    http://cgi.ebay.com/LEOPARD-Boat-367...item45fa93409c

    http://cgi.ebay.com/leopard-BM-4074-...item43a6be923d

    http://cgi.ebay.com/Leopard-LB-4274-...item2a0b3dc94d ( the nicest option regards spec vs price )

    They are all somewhat more $$ than the ********* or 8XL, but you get something much more powerful and durable/ resilient for what you spend- pair one of those with a solid ~80-150amp 4s esc and you cant go wrong.

    I hear you on the tire issue, many guys are swapping over to something different as new designs appear on the market.

    A nice fat dewalt motor installation would be great in my eyes- you get more power and better temps than the stock setup, a motor than lasts much longer and is rebuildable quite often ( replaceable brushes ), and there are also many threads around on the subject so you aren't short of reading material & know what to expect as such- 14.4v dewalt is prefered for 4s lipo use/ 14 nimh cells, direct fit more or less and very little setup work to do besides a little soldering to fit the wires...

    Tough call, but I would go dewalt and enjoy the extra power- you can always grab a new truck later down the line to embrace your inner speed-freak
    Keeping the Mods busy is my specialty...

  15. #15
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    Not really that into out and out speed although would enjoy a ***** drive by. Since I will use 4s Lipo I would have thought a Dewalt 12V with a bit of overvolting should give more than a 14.4v which is running at almost the designed voltage (4s = 14.8v)?

    I can reuse the stock Traxxas ESC (but I would go for a separate BEC as I don't like the way Traxxas tap off one side of the battery which end up with one pack always draining faster than the other)

    In this case I should really sell my brand new Kershaw Gen 2.2 system? I have not fitted in yet

  16. #16
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    I been reading this and Iwasalso wondering about the kershaw system, but Armyofdarkness says a dewalt will run smooth on the truck. Does it run better then the 775?

  17. #17
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    Quote Originally Posted by rockeater View Post
    I been reading this and Iwasalso wondering about the kershaw system, but Armyofdarkness says a dewalt will run smooth on the truck. Does it run better then the 775?
    Yes much better I am about to order me two more dewalt motors for trucks I'm building.... I have the 12v now but would suggest the 14.4 as it will run cooler
    No you cant drive it
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  18. #18
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    Is there a specific 14.4 to look for? I see alot on ebay or is there a better vendor?

  19. #19
    RC Turnbuckle Jr. jamann's Avatar
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    QUOTE=tranworld;4803155]Not really that into out and out speed although would enjoy a ***** drive by. Since I will use 4s Lipo I would have thought a Dewalt 12V with a bit of overvolting should give more than a 14.4v which is running at almost the designed voltage
    (4s = 14.8v)?
    A fully charged 2s pack is 8.4v so 16.8v for 4s

    I can reuse the stock Traxxas ESC (but I would go for a separate BEC as I don't like the way Traxxas tap off one side of the battery which end up with one pack always draining faster than the other)

    In this case I should really sell my brand new Kershaw Gen 2.2 system? I have not fitted in yet[/QUOTE]
    I am trying a ******* sensored/sensorless 150a esc and the xerun sensored 2250kv as mentioned by army above.Waiting on the motor..rotating postal strike in Canada so that may add some wait time just ordered it after doing some research.
    Gambling the sensored function will work together?Not sure if all sensored esc's and motors are compatible.Keeping the dewalt setup for fall and winter when it's wet full time.....Changed tires long ago..... shredded the canyons they are very thin but grippy
    Mountains cant stop me
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