Reverse on a starter

[OldNick]

My Valk trike has a reverse system based on some car's starter motor, connected to a flywheel on the drive shaft. It's primitive but effective. Trouble is, being a starter motor it draws huge current and is is way too fast and powerful for the job, as geared.

I tried it fpr the first time last evening and, because the battery was a bit low, it was not that fast, but stalled very quickly. Firing up the motor, I lifed the battery and got some reverse. But it takes so much power that unless the battery is top hat, if I have the engine running and ask for reverse, the engine dies! So the reverse is sucking away the ignition!

The previous owner warned me that the reverse is scary fast if the battery is charged. So it is way overpowered and high geared, both because it is too fast and because it draws huge current and demands a lot from the system.

I can think of various ways to gear the system, or PWM the motor (I know that at several hundred amps starter motors are a biznitch for this) , but are there standard, accepted, reasonably-priced ways to deal with this?

Any ideas? I can fix this, but I do not want to reinvent the wheel.

Nick

 

[clint44]

How about a slower rpm motor?

 

[Dirtydan]

And maybe one that uses less juice. maybe a motorcycle starter. Sounds like you are using an automobile starter.

 

[OldNick]

Howdy. Thanks for the replies. Yes it is a car starter motor. I _think_ a Hilux.

I doubt I would find a starter motor that was significantly slower. They tend to be of similar speed, because they all work on the ring gear of a flywheel, which will be of much the same size, and crank speeds will be pretty much the same on different engines.

I wondered about a bike starter, because I imagine they are not only less powerful but slower. But the problem is actually linking it to the drive shaft. Even a bike starter has serious torque and would need a pretty capable driven gear to handle it. And finding such a gear that will then fit the driveshaft of the trike....obviously the beauty of the flywheel ring gear is that it just sits on a spline on the existing driveshaft, all nicely designed and built for me by a Japanese car maker.

I guess I need to look at a bike starter and hope that the teeth on its cog match the rig gear on my flywheel. It's either that or some sort of belt system, I guess.

Nick

 

[rhino 2]

If you can find a reverse motor from a Tri-Glide, Their made by Hitachi and spin/turn very slow...
That might work for you ???

 

[OldNick]

If you can find a reverse motor from a Tri-Glide, Their made by Hitachi and spin/turn very slow...
That might work for you ???

OK. Thanks! AFAIK Triglides are pretty rare in Aust, as I gather they can only be imported by individuals or boutique buyers and not Harley dealers. Supposed to tip over too easily. Maybe it's being upside down here!

Nick

 

[Bikerbozo]

In the past, I have had to rev a little throttle when using reverse on my TriGlide to avoid engine dying.
A smaller gear on your reverse motor would also slow it down. Think of it this way. If gear has 10 cm circumference. That is how far it goes after 1 rpm. Smaller gear, say 5 cm, would travel 1/2 the distance. So reverse would go slower when backing up.

 

[OldNick]

In the past, I have had to rev a little throttle when using reverse on my TriGlide to avoid engine dying.
A smaller gear on your reverse motor would also slow it down. Think of it this way. If gear has 10 cm circumference. That is how far it goes after 1 rpm. Smaller gear, say 5 cm, would travel 1/2 the distance. So reverse would go slower when backing up.

Interesting that even "official" reverse motors can kill the engine. I will keep note of that.

Yeah I get that about the gearing. But the trouble is, as with most starter motors, the cog that's on there is about as small as it can get and still go around the shaft! Any less teeth, which have to match the teeth on the ring gear in size, and you would have to have gaps to make a cog. I could maybe manage ....one less tooth, but that's probably 1 in 12-13 and that's not much gain, in slower speed or torque. I would be looking at halving the speed and doubling the torque as you mentioned.

I actually thought about one of those electric pushbike motors, because you can get 1000W ones. But trouble is they need 48V to get there.

I am sorry if I seem to be nay-saying suggestions. I am taking them all on board and they may well give a hand somewhere. Thanks, guys.

Nick

 

[cavie]

OK. Thanks! AFAIK Triglides are pretty rare in Aust, as I gather they can only be imported by individuals or boutique buyers and not Harley dealers. Supposed to tip over too easily. Maybe it's being upside down here!

Nick

tip over????????? who thought that up????????? Nothing has tipped over since the 70's Honda ATV 3 wheelers!!

 

[rhino 2]

tip over????????? who thought that up????????? Nothing has tipped over since the 70's Honda ATV 3 wheelers!!

:Agree: I had 3 Honda ATC's [Big reds] Yep if you didn't know what you were doing the'll turn Turtle on you real quick.. But Street Trikes don't tip... They have differentials not locked rear's like ATC's have..

 

[OldNick]

tip over????????? who thought that up????????? Nothing has tipped over since the 70's Honda ATV 3 wheelers!!

Not me mate! It is what I have seen said. Yeah I have ridden the 3-wheel ATVs and having to lean _out_ on a turn was just weird.

Nick

- - - Updated - - -

I had 3 Honda ATC's [Big reds] Yep if you didn't know what you were doing the'll turn Turtle on you real quick.. But Street Trikes don't tip... They have differentials not locked rear's like ATC's have..

I do have to mention the people killed and injured on "quad bikes".

Nick

 

[rhino 2]

Not me mate! It is what I have seen said. Yeah I have ridden the 3-wheel ATVs and having to lean _out_ on a turn was just weird. Nick - - - Updated - - - I do have to mention the people killed and injured on "quad bikes". Nick

People that do nothing also get injured and die.... And the sad part is while their getting injured and die, They weren't having any fun in the process:laugh::laugh: