Hi Guys,
Id like to buy one or two S28-400 Magmotors (and controllers if you have them). If anyone has some lying around or if you live in Melbourne and dont want to sell but would hire them out for a fee please let me know.
Best regards Mark
Sat Aug 30, 2008 2:38 pm
dyrodium Experienced Roboteer
Joined: 24 Aug 2004
Posts: 6476
Location: Sydney
I don't know if anyone even owns those motors in aus, they're really high tech! Much less so controlers. Is that much power really needed in your application? _________________ ( •_•)
Hi Thanks for your reply.
"Is that much power really needed in your application?"
Good question!
Actually I need quite a bit more, I was going to use the Mag motors for some preliminary testing. The motors Im going to use for the final design will either be Neu Motors 2230s 10kw or Plettenberg Predators 37/6s 15kw. The mag motors will be a relatively cheap alternative to fine tune the design before I order a pair of these expensive brush-less motors.
it not for robot use but I know you guys use some big motors so it was worth a try.
Maybe someone out there has some under their bed. Heres hoping.
Hey has anyone had trouble importing big motors from Robot Marketplace?
Regards Mark
Sat Aug 30, 2008 5:01 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Importing motors or anything else from the RMP is easy! The Mag motors are a special case as they are often shipped direct from the factory, which costs more shipping. If the RMP happens to have them is stock, they will knock off the expensive shipping.
The main trick is to ask that the custom form says "parts for model (or toy) robot" this category doesn't get GST applied and you avoid the extra 10%. Shipments under $500 almost never get GST no matter what they are.
If you do happen to import a long Mag, I would be interested to buy it after your testing is done. What needs two of those giant Neu motors, if you don't mind me asking?
Sat Aug 30, 2008 7:02 pm
markoid
Joined: 29 Aug 2008
Posts: 7
Thanks for the tips.
Im using the motors to power large model airplane propellers multiblade 20-34 inch. These are usually powered by 150cc -200cc two stroke motors up to 20hp. So I need extrapolate the data from lower rpm at half that hp to determine flow separation efficiencey etc. Unfortunately as good as computer models are at some point you still have to corrolate the date with real world tests. Expensive but fun.
Regards Mark
Sun Aug 31, 2008 10:59 am
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
if your gunna stick with petrol get a BZM 6 port 50cc motor, i have a dyno graph of mine with 17.9hp off the crank. id imagine theyd be a ton lighter too _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Sun Aug 31, 2008 11:09 am
DumHed Experienced Roboteer
Joined: 29 Jun 2004
Posts: 1219
Location: Sydney
yeah I'd just run a petrol engine and measure the torque it's putting into the prop (have the engine on a rotating mount with an arm to a spring balance or load cell)
I'm interested in these propellers though. Where do you get them? _________________ The Engine Whisperer
- fixer of things
Sun Aug 31, 2008 11:25 am
markoid
Joined: 29 Aug 2008
Posts: 7
Hi Guys thanks for the input. Very cool forum.
My experiments are to optimize Pitch distribution of the props & their relation to an aerodynamic shroud. The tip clearances for the shroud tolerances are important so vibration from a two stroke will just cause me grief also the 2 stroke powerband will also get in the way. There are many parameters to optimize so electric is the way to go.
The idea is to pump as much air through the duct/shroud with as little loss as possible.
The great thing about electrics is they are almost vibration free, and you can throttle them from 0-x rpm bit by bit watching whats happening to die/smoke trails and tufts of cotton to determine areas of loss eg turbulence and separation especially on the walls of the duct.
Too much fun really but getting powerful motors that are not physically too big means looking at the top end of the market.
Best regards Mark
Ps to begin with I will use off the shelf props from various makers eg Bolly.Mejzlik etc.
Sun Aug 31, 2008 4:43 pm
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
honestly for the power your looking at and the $$$ required youd be best off making your own brushless. been done many a time before and build it to fit the design perfect. _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Sun Aug 31, 2008 4:54 pm
markoid
Joined: 29 Aug 2008
Posts: 7
Yeh there are not too many Brush-less motors in the 10-15kw range especially if you want a reliable esc to go with it. Basically stuck with Plettenberg Nue or maybe Hacker but they have been promising the H200 for over a year now so Im not holding my breath.l So at the moment there is only 3 manufacturers worth looking at, the problem is if I dont have my numbers right I could end up withe the wrong winding and blow the efficiency. You are right Brush-less will be the way to go once things are finalized. Each motor + esc will cost around $2500.00 so Id better be right about my specs. I will need between two and four motors so even though it sounds expensive a couple of mag motors and controllers is actually the cheap way to get the design right. As for building my own Brush-less motors Ive made some small ones but the really big ones are out of my skill set.
Regards Mark
Ps Ive even considered belt driving an Etek on the test stand, not perfect but it might do the trick.
Sun Aug 31, 2008 5:09 pm
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
if you want dude i have a full brushless etek setup i want to get rid of for about $1000 or so. has the sevcon controller, solenoid and the wiring looms and power cables all done for it _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Sun Aug 31, 2008 5:21 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
If it is just for bench testing, how about a large car starter motor? You would have to hack off the gear on the end, but the motor would be very cheap from a car wrecker's yard. The Roboteq 2550 single channel controller should be about right for controlling it.
Sun Aug 31, 2008 5:38 pm
markoid
Joined: 29 Aug 2008
Posts: 7
Using An Ibc on a
I think a starter motor would be ok but the the Magmotor seems pretty versitile as a test motor. Heres another question: Would it be possible to run the Magmotor off an IBC. For example would I be able to run both IBC motor outputs to the one Magmotor and have double the current rating. Because the motor will be run for short periods of time and it will create quite a blast of air and the addition a finned heatsink plate might provide enough cooling.
Wed Sep 03, 2008 12:49 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
No, an IBC would be toast very quickly! Its a good controller but will not source the amps you need, even with a larger heatsink. The peak current a long mag motor will draw is likely to be over 200A and that sort of power will melt the FETs. BTW: the mag motors all have dual windings, so it is possible to use a dual channel controller with one output powering a separate winding. This opens up the range of controllers you can use and might save money.
The starter motor is the budget solution, while the magmotor is the Rolls Royce; which way you go depends on your budget...
Wed Sep 03, 2008 2:09 pm
markoid
Joined: 29 Aug 2008
Posts: 7
You are right! I love the IBC but it was not designed for a Magmotor.
If Bret made a bigger ESC I would buy that.
After much research Ive come to the same conclusion The AX2550sc is the way to go. Now I just have to figure out if I should order the separately motor and esc separately to keep underr the $500 per order limit to avoide costly attention from customs.
Mark
Wed Sep 03, 2008 2:30 pm
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