Topic: Two motors on one shaft (Read 8676 times)

Southern Sailor · « **on:** August 23, 2015, 01:38:19 pm »

Has anyone used two motors on one shaft? I am looking at driving the Billings Zwarte Zee using two type T4a motors from MMM on the one shaft. It would need a gearbox, pulleys and belts. Any tips out there? Thanks and Cheers. Brian

Jerry Hill · « **Reply #1 on:** August 23, 2015, 02:14:21 pm »

Can't help with experience other than recommending motionco.co.uk for HTD drive belts and pulleys.

Tug-Kenny RIP · « **Reply #2 on:** August 23, 2015, 03:35:48 pm »

May I ask why you need to use two motors. Are you after power or speed. ?

ken

Mark T · « **Reply #3 on:** August 23, 2015, 03:36:19 pm »

Hi Brian - I have never done this but just thinking it through I was wondering how the motors could be at exactly the same speed at the same time throughout their rev range.

I could see one motor pushing the other along to a certain extent and as the motors you want to use are powerful low torque motors maybe this could cause heat build up in one or both of the motors. I may be way off here and I will be very interested to see if anyone has ever done this successfully.

An interesting post :)

Martin (Admin) · « **Reply #4 on:** August 23, 2015, 03:42:28 pm »

Yes the motors would best be identical otherwise you would get efficiency losses.

... there was another topic about this subject recently: http://www.modelboatmayhem.co.uk/forum/index.php/topic,51776.msg530324.html#msg530324

John W E · « **Reply #5 on:** August 23, 2015, 03:54:42 pm »

http://www.modelboats.co.uk/albums/member_photo.asp?a=32229&p=574295

aye
John

sparkey · « **Reply #6 on:** August 23, 2015, 03:55:34 pm »

Many years ago I saw a rather large tug powered by two MFA 850 motors in tandom,why the owner none it I have no idea,I know it was turning a big prop and he wanted extra power who knows,I can't see any advantage in this power train and don't know the problems this may cause,I never seen two motors driving one shaft before or since,I myself would have used a fan motor which is ideal for this application.......Ray.

Southern Sailor · « **Reply #7 on:** August 23, 2015, 04:17:56 pm »

Wow, how's that for a quick response. Sunday afternoon seems to be a good time to post if you want a quick answer. I have two T4as and really like them - but one seems a bit small for the tug. Of course that is just a feeling and no technical reason, but the saying from one of our forum members "if it ain't broke, fix it anyway" comes to mind, and this is an interesting little exercise. Truth is that the T12 from MMM (the next size up in their range) seems a bit heavy and large for this model (by looking at the quarterdeck area of this model there seems to be very little freeboard - in our club, and before my time, a member went astern too fast with a model of the same boat and sank it) and costs a bit too much for me at the moment (exchange rate is twenty-to-one right now), hence the thought process. I suspect there will be a problem of the one motor having slightly different characteristics to the other and as such some power will be lost in trying to overcome the difference. What I would be looking for is the design of belt and pulley systems and I see there are some references in the replies to a possible source of decent pulley-and-belt sets which could be built into a gearbox. Thanks for the help so far. (I see there are some more answers on the topic while I am writing so I may have duplicated in this post but I'll send it anyway). Cheers. Brian

Shipmate60 · « **Reply #8 on:** August 23, 2015, 09:59:21 pm »

Some of the early Kyosho fast electrics had a fixed gearbox with 2 x 550 type motors driving single shaft so the gearboxes should be available.

Bob

Martin (Admin) · « **Reply #9 on:** August 23, 2015, 11:27:46 pm »

Oh yes! I forgot about those!
I used a couple of Graupner Hydrosdpeed units..... very power hungry!

Southern Sailor · « **Reply #10 on:** August 24, 2015, 07:13:10 am »

Seems the general consensus is stick to one T4 and use a larger motor if required. The T4 or similar has been recommended for the ZS. Thanks for the discussion. Cheers . Brian

thething84 · « **Reply #11 on:** August 25, 2015, 03:26:25 am »

Quote from: Southern Sailor on August 23, 2015, 04:17:56 pm

Wow, how's that for a quick response. Sunday afternoon seems to be a good time to post if you want a quick answer. I have two T4as and really like them - but one seems a bit small for the tug. Of course that is just a feeling and no technical reason, but the saying from one of our forum members "if it ain't broke, fix it anyway" comes to mind, and this is an interesting little exercise. Truth is that the T12 from MMM (the next size up in their range) seems a bit heavy and large for this model (by looking at the quarterdeck area of this model there seems to be very little freeboard - in our club, and before my time, a member went astern too fast with a model of the same boat and sank it) and costs a bit too much for me at the moment (exchange rate is twenty-to-one right now), hence the thought process. I suspect there will be a problem of the one motor having slightly different characteristics to the other and as such some power will be lost in trying to overcome the difference. What I would be looking for is the design of belt and pulley systems and I see there are some references in the replies to a possible source of decent pulley-and-belt sets which could be built into a gearbox. Thanks for the help so far. (I see there are some more answers on the topic while I am writing so I may have duplicated in this post but I'll send it anyway). Cheers. Brian

haha my saying has been mentioned.

jarvo · « **Reply #12 on:** August 25, 2015, 09:36:19 pm »

As shown in the link above, thats my club mate Bob Able, those motors and the boat have been in a very long build thead on the model boats web site, he used 4 MFA850 motors in paired belt drive units, boat goes well but big and heavy. Great experiment but why????, fan motors would do the job better for far less cost

Mark

RAAArtyGunner · « **Reply #13 on:** September 03, 2015, 04:48:01 am »

Found this in my archives.

Tried to find web link but it appears defunct, not surprising seeing print date was 2006.

However it might further confuse the issue.

Southern Sailor · « **Reply #14 on:** September 03, 2015, 04:28:00 pm »

Looks interesting. My penny's worth is that presumably the ESC (or MSC) would need to be able to handle 14.4 V. Further than that, I am way out of my depth and leave it to the clever guys to comment further. Brian

Martin (Admin) · « **Reply #15 on:** September 03, 2015, 05:08:10 pm »

resampled...

TheLongBuild · « **Reply #16 on:** September 03, 2015, 06:28:14 pm »

Its all good fun.. Maybe no benefit but it looks good compared to two stand alone motors..

Perkasaman2 · « **Reply #17 on:** September 03, 2015, 11:59:34 pm »

This installation above an interesting one-off but a single larger motor will provide a lot more torque and turn a larger prop. A comparison test to see which configuration is more battery efficient would be very interesting.

Martin (Admin) · « **Reply #18 on:** September 04, 2015, 06:32:05 am »

What it lacks in efficiency it makes up for visually appeal! Win!

inertia · « **Reply #19 on:** September 04, 2015, 07:59:15 am »

Quote

What it lacks in efficiency it makes up for visually appeal! Win!

Not necessarily - beauty being in the eye of the beholder. Ugh!
DM

Martin (Admin) · « **Reply #20 on:** September 04, 2015, 09:47:12 pm »

Here Dave, borrow my beer goggles:

RAAArtyGunner · « **Reply #21 on:** September 04, 2015, 11:47:33 pm »

Thats Aussie beer in that glass

Martin (Admin) · « **Reply #22 on:** September 05, 2015, 06:21:40 pm »

Topic clean up and locked.

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Author Topic: Two motors on one shaft (Read 8676 times)

inertia