noddywa

Hi All..Just the other day, while waiting for a friend (in public waiting area) I picked up a RC mag and had a read, dated from memory in the 80's an article on how someone was attemtping to place two motors inline , one in front of the other hence inline for those who are trying to follow,, the shaft on the first motor was a little longer to couple up to the motor behind ,,
unfortunately some of the article was torn out and couldn't find out exactly in what water vessel he was going to put it in ,,
the next edition that it was supposed to be in was not there to read bugger !!

anyone have any idea and how this could be used with todays rc technology ??
BE nice !!

jkotlanger

I have seen an inline configuration used in electric torpedos for scale PT Boats which allow one to use counter rotating shafts. John Drain's www.pt-boat.com site has a description of the inline motor approach and the gearing required to drive the torpedos. I am currently building the PT596 and will be using this same configuration. I have not seen it used on boat applications, but its purpose in the torperdo is to neutralize left or right pull of the prop so that the torpedo can be accurately fired at a target without additional steering mechanisms. The torpedos using this system are fast and accurate. We have built a prototype and tested in the pool last year and it ran straight and true right into my rib cage resulting in a cracked rib from a torpedo that is only 10 inches long (1/20th scale). We got the gears from the small little r/c car kits that Radio Shack sells. Props were home made from wheel collar with blades.

eboat

I was thinking of putting 2 motors in line also . I found at a surplus store for $4 each battery drill motors that had the shaft coming out each end and just hook them end to end . I am trying to put two pairs of them in this boat , 2 on each prop

Wheelnut

My Feedback: (81)

This was done not too long ago, the guy posted it in RCU but I can't remember what thread it was in. Not much came if it because the added weight was not worth the extra power plus the fact that two motors will never run exactly the same and therefore, efficiency will not be all that great. I believe he wound up getting a 700 or 800 motor that made much more sense.

Forgot to mention, there was also a guy that used a belt (like a fan belt but smaller) to connect the motor to the shaft.

ryan_t888

Mounting two power sources in line is more commonly found in larger gas boats.

Ryan

LtDoc

noddywa,
Two 'in-line' motors are used, generally, when a single larger motor isn't practical for whatever reason. If the two smaller motors are '=' to the larger motor, fine. If more powerful, maybe even 'finer'. If less powerful than the larger motor... @#$ just add a third motor in-line! With in-line motors you're sort of talking 'torque', not increased rpm. And if both motors aren't '=', then it's a waste of time, the weak one is a drag on the stronger one. And if the second motor is strong enough to make up for the weaker first motor, why have two to start with?
- 'Doc