Timing GWS 370 motor - a picture tutorial - Page 2

frankenfoamy · Mar 06, 2003, 11:07 AM

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

)

Grejen · Mar 06, 2003, 11:10 AM

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.

Biggles604 · Mar 06, 2003, 12:07 PM

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.

kensp · Mar 07, 2003, 03:11 AM

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

Biggles604 · Mar 07, 2003, 12:23 PM

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?

uncled · Mar 07, 2003, 01:01 PM

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

kensp · Mar 07, 2003, 04:18 PM

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

hoppy · Mar 07, 2003, 06:55 PM

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

ParkJeff · Mar 08, 2003, 03:30 AM

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

wildpalms · Mar 08, 2003, 07:02 AM

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

hoppy · Mar 08, 2003, 08:21 AM

I like MPJet gear boxes, they spin in the right direction, and are a lot tougher than the GWS boxes.
hoppy

msp1957 · Mar 09, 2003, 09:24 AM

Where can these be purchased?

michael

uncled · Mar 09, 2003, 09:31 AM

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.

BEA flyer · Mar 09, 2003, 09:48 AM

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????

WhiteCloud · Mar 09, 2003, 09:59 AM

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

Mar 08, 2003, 03:30 AM	#24
ParkJeff Who moved the runway? Join Date: Feb 2003 Location: Australasia Posts: 704	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 09, 2003, 09:24 AM	#27
msp1957 Registered User Join Date: Oct 2002 Location: W. Bloomfield, Mi Posts: 505	split-ring pliers Where can these be purchased? michael

Mar 09, 2003, 09:48 AM	#29
BEA flyer Registered User Join Date: Jun 2002 Location: Concord, MA Posts: 829	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, 09:59 AM	#30
WhiteCloud Stupid Gravity Join Date: Aug 2002 Location: alsip, ill Posts: 499	Thanks! This thread is perfect! I can not wait to try this modification!

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Mar 06, 2003, 11:07 AM	#16
frankenfoamy Strange Plane Central Join Date: Dec 2000 Location: Poway (near San Diego), CA US Posts: 1,843	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 )

Mar 06, 2003, 11:10 AM	#17
Grejen IAMCANADIAN Join Date: Jul 2002 Location: Gibsons, B.C. Canada Posts: 3,705	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, 12:07 PM	#18
Biggles604 Blissfully Ignorant Join Date: Oct 2002 Location: Port Moody, BC, Canada Posts: 235	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, 12:23 PM	#20
Biggles604 Blissfully Ignorant Join Date: Oct 2002 Location: Port Moody, BC, Canada Posts: 235	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, 06:55 PM	#23
hoppy Registered User Join Date: Oct 2000 Location: Key West Posts: 13,109	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, 08:21 AM	#26
hoppy Registered User Join Date: Oct 2000 Location: Key West Posts: 13,109	I like MPJet gear boxes, they spin in the right direction, and are a lot tougher than the GWS boxes. hoppy