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Mar 06, 2003, 10:07 AM
Strange Plane Central
frankenfoamy's Avatar
Great thread!!
May I add that typically we advance time about 5 mm in the opposite direction of intended shaft rotation. The mabuchi 370, for whatever reason, comes pre timed for the rotation of a direct drive tractor prop. No need to time it in that use.
The motor in a GWS gearbox comes, in effect, retarded timing!!!
That is why it needs 10 mm endbell (backplate) rotation.

Peter, your explaination is good or better than any I have seen.
(that means I could understand it )
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Mar 06, 2003, 10:10 AM
IAMCANADIAN
Grejen's Avatar
Thank you. I'm gonna try that for sure. My 300C has almost 100 flights on it now (just short of 600 minutes) mostly on 7 cell NimHs. Seems fine but more effeciency is always music to my ears.
Mar 06, 2003, 11:07 AM
Blissfully Ignorant
Biggles604's Avatar
One thing I have never understood, is why GWS keeps buying the Mabuchi motors with the brushes and timing set to run CCW when they are then going to put them into a gearbox and run them CW. Mabuchi motors are fairly generic, is there not a similar and equally affordable motor out there that has the brushes installed for the opposite rotation?

How hard would it be ro remove the end plate and pull out the brushes and re-seat them the right way? I know getting the spring tension would be really hard.
Mar 07, 2003, 02:11 AM
Registered User
kensp's Avatar
Quote:
Originally posted by Biggles604

How hard would it be ro remove the end plate and pull out the brushes and re-seat them the right way? I know getting the spring tension would be really hard. [/B]
Impossible. What is needed is a new set of mirror image brushes. It would be very simple to do during manufacturing though.

Ken
Mar 07, 2003, 11:23 AM
Blissfully Ignorant
Biggles604's Avatar
Yup, I realised it as soon as I sent it, I keep forgetting that the order is think, then type...
Doh!

Why doesn't GWS send motors built correctly for gearbox usage?
Mar 07, 2003, 12:01 PM
Registered User

Re: question


Quote:
Originally posted by scooternewbie
Great post!

I think I might like to try this in the future, but I just maidened my slow stick today (after some touch and go "learning" on a sky scooter). I wanted to break in the motor before flying with it, but couldn't get it out of the gear system it came with. I took out the screws, but it just wouldn't budge. Is there a secret to getting it out?

I hope to be able to break in the motor I'll buy to replace this one and maybe start tinkering around with the timing.
I usually just put both thumb nails on the pinion gear and holding the case start applying pressure - - - never hd a problem yet of getting the motor to slide out
Mar 07, 2003, 03:18 PM
Registered User
kensp's Avatar
Quote:
Originally posted by Biggles604
Yup, I realised it as soon as I sent it, I keep forgetting that the order is think, then type...
Doh!

Why doesn't GWS send motors built correctly for gearbox usage?
They probably purchased a large batch and havn't used them all up yet. Or the minimum order for specialy made reverse motors is to large.

Ken
Last edited by kensp; Mar 07, 2003 at 03:21 PM.
Mar 07, 2003, 05:55 PM
Space Coast USA
hoppy's Avatar
With some motors, it's possible to turn the end plate without undoing the tabs if you have a c or snap-ring pliars which gives a good grip on the plate.
hoppy
Mar 08, 2003, 02:30 AM
Birds do it, bees do it
ParkJeff's Avatar

S300 in reverse


Hi guys,

I have been doing some thinking about the lifetime issue with EPS-300 (Speed 300) motors (and others which we run opposite to their intended direction) and have what is no doubt a silly question. Hope you will bear with me.

Is it true that pusher props (for example http://www.hobby-lobby.com/grprop.htm#Pusher) are designed to spin in the opposite direction as normal (tractor) props when looking from the nose of the plane?

If so could we take a pusher prop, flip it around and install it on an EPS-300 gearbox so that the side that normally faces the motor (on a pusher plane) is now facing away from the motor on the EPS-300 and then run the motor the opposite way (ie. the direction Mabuchi intended it to be run)?

This would help with the problem of breaking brush wipes.

Comments? What am I not seeing?

Jeff
Mar 08, 2003, 06:02 AM
Professional idiot
Quote:
Originally posted by Biggles604
Why doesn't GWS send motors built correctly for gearbox usage?
Mabcuchi don't make one that runs CW. Even GWS is small fry when it comes to production of these things. Production of the 370 must be well into the millions by now.

I think a better question would be why GWS don't design their gearboxes to take account of this. Most other manufacturers seem to have got this right. It seems strange to cripple yourself from the get go by producing a system that is down on power from it's potential.

--
Dave
Mar 08, 2003, 07:21 AM
Space Coast USA
hoppy's Avatar
I like MPJet gear boxes, they spin in the right direction, and are a lot tougher than the GWS boxes.
hoppy
Mar 09, 2003, 08:24 AM
Registered User

split-ring pliers


Where can these be purchased?

michael
Mar 09, 2003, 08:31 AM
Registered User

Re: split-ring pliers


Quote:
Originally posted by msp1957
Where can these be purchased?

michael
About any auto parts store should have them. Maybe even a Tru Value Hardware store.
Mar 09, 2003, 08:48 AM
Registered User

pusher props and gearboxes


Yeah, if you get a pusher prop and put it on a gearbox that reverses the rotation of a motor, with a non-reverse timed motor, you should end up with a set-up that runs the motor the right direction. You will discover that your choices for prop size are quite limited, however. You could also always turn the motor to face the other way, a la Wingo. If you don't have a tach, you should be able to figure the way a motor is timed by listening to it, then reversing the power leads. The direction it sounds faster in is the direction it is probably timed to turn in. I would not be surprised to find that some of the cheaper motors used for park fliers are actually neutral timed, in which case they will be slightly more efficient if you change the timing for forward or reverse operation. But if you really are interested in efficiency and are willing to put that kind of effort into it, I have to ask why you just don't go out and buy a brushless motor and ESC????
Mar 09, 2003, 08:59 AM
Stupid Gravity

Thanks!


This thread is perfect! I can not wait to try this modification!