Printable View
Can anyone think of a comparable motor to Motenergy ME-0708 Brush-Type Permanent Magnet DC Motor. Especially if its located in the UK.
http://www.evdrives.com/product_p/mot-me0708.htm
I have been looking for ages I cant come up with anything.
Cheers,
Regards Lewis
That looks like an Etec. Anything that comes close will be expensive and/or heavy.
What is the purpose for the motor?
You are correct its the replacement for the Etec-r I believe. Its use is a weapon motor. Its looking like £400 shipped from the states.
Regards Lewis
Don't forget the import tax and duty!
That is why I want to find something in the UK really.
Sadly you'll struggle, at least with brushed at those power ratings in the UK. Similar high power motors would be LEMs, Perms or magmotor (now called ampflow). You can occassionally find some of them on ebay but it is rare.
I can't recall the exact details, but a US heavy builder used a Perm motor and destroyed it in it's first match - apparently the winding is poorly supported and impact shock crushed the wiring & destroyed the motor. Have you tried searching Alibaba to see if the Motenergy motor is available cheaper direct from China?
Why not looking at the more modern solutions. A Rotomax 150cc for example.
http://www.hobbyking.com/hobbyking/s...dProduct=31195
I'd like to see how that performs in a heavy! IMHO, it is more expensive than an Etec brushed motor as you need a large ESC rather than a contactor to drive it. If Hobbyking has it in the local warehouse along with a suitable ESC, that might make it cheaper again. The Rotomax will probably also need battle hardening along the lines of what I did to my Rotomax 1.6.
The Rotomax 150 is over 10Kg lighter than the Motenergy ME-0708 and much smaller, which makes it an interesting option if you wanted extra armour.
Most of the commercial brushed pancakes seem to die every time they have a sudden stop or reverse. Brutus as point in case, and even the champion of LEM's , Storm 2 went over to the traditional side with the changeover to Ampflow.
In sort, even the venerable Bosch 750 needed battlehardening. But as far as I know, there isn't a EU or Aussie roboteer that battlehardened a Brushed Pancake with any degree of succes.
I know I won't even try. In my opinion the construction of the basics is way to feeble.
Agreed; any brushed motor has issues with impacts. I used to go through a set of Magmotor brushes every 3 or 4 matches and that's on a good day when the magnets didn't come loose :).
yeah you'd be silly to go brushed pancake *looks nervously over at perms in the corner of the room*
Has anyone ever looked at industrial frameless brushless motors? They are a DIY type of motor where you get the stator and rotor and you make your own case, bearings and output shaft. I used to think they were a bit too difficult to use but after hacking a Rotomax the idea is less daunting.
Motenergies are good motors indeed, much better than the original Etek IMHO. The brush setup is magnitudes better. Cant imagine any hobby brushless motors approaching its capability for the price.
I used a LEM 170 as the weapon motor on Supernova, never had any issues with the brushes, but then the motor was only required to work one way and there was a clutch to stop sudden shocks.
Why did Storm stop using LEMs?
Lemco changed the way the motors were produced to make them cheaper to manufacture apparently. The old ones were great but there's a lot of talk about the latest ones being by so good with shock or direction changes. A good hardened motor is the Agni 95 or or wind. Cedric Lynch moved on from Lemco and has been designing these newer motors with his new company (now called Saietta Group). They look the same as the Lem's but much improved.
Ok, my LEM is pretty old, 1980-1990s.
Good vintage :)
Thanks for all the input guys. Looks like I will be sourcing a couple of motors from china as per overkills suggestion. To be honest I am not sold on the brush-less motors yet. But to be fair Ive only used small ones in drones etc. Reading up on the RotoMax 150cc it looks promising, considering also you can couple two or more of these on the same shaft to increase torque. I guess the only way to see if it works is to try one. the weight saving would be nice.
The rotomax 100cc should reach 9nm of torque. The 150 is a size bigger. With the higher RPM compared to brushed motors you can play more with the gearratios. I believe with some gentle persuation and battlehardening the big brushless are a fine option for weaponmotors.
The biggest thing to consider with brushless motors in heavyweights for both drive and weapons are its thermal mass. An ETEK or other large brushed motors have a very large thermal mass and can be pushed to their limits for far longer periods before getting too hot and burning up. This means your brushless motors really need to be highly overpowered and geared correctly for the job they are doing to ensure they're running under far less load and in a more efficient state to minimise heat build up. Warhead runs the Scorpion 7050 motor with good success on the disc.
Did you modify the mounting at all? For all the motor's 10KW and 1.7Kg weight, Scorpion still uses M4 screws to hold it down.
Gearing motors to save them.
Due the higher RPM of the brushless motors compared to brushed motors (6000+ for the Rotomax 100cc @37V) you can gear 'm down more, making the workload a tad less straining.
Nick, the scorpion motor had an extended shaft made on the rear of the motor with a flange that bolted on the rear case to help minimise the outer casing from flexing and had a rear bearing to take the stress off the front bolts.