Self starting generator without separate starter motor?

Poor old sod

Joined Jul 25, 2017
108
Thinking in the early morning: try a sewing machine motor [Singer, external, bolt-on, pulley drive] driving an inertial engagement [Bendix] of a rubber wheel onto the rotor. use a tapered wheel with the shaft at an angle will make engagement better than parallel shafts. Far easier than limiting/interrupting the current to protect my low power inverter. I only need to deliver 80W or so for up to 20sec.
 

shortbus

Joined Sep 30, 2009
7,760
Thinking in the early morning: try a sewing machine motor [Singer, external, bolt-on, pulley drive] driving an inertial engagement [Bendix] of a rubber wheel onto the rotor. use a tapered wheel with the shaft at an angle will make engagement better than parallel shafts. Far easier than limiting/interrupting the current to protect my low power inverter. I only need to deliver 80W or so for up to 20sec.
What make and model is the engine you want to start? Most modern day engines have two versions - electric start or pull start. If this was my problem I would look for a similar engine that was electric start and take the flywheel and starter from an electric start motor and put it on my motor, as long as it is the same basic engine they will interchange. The only difference between the two types is the electric start one has gear teeth machined on the circumference of it and the pull start doesn't.
 

Poor old sod

Joined Jul 25, 2017
108
1.5aH AEG Li-ion 12v battery; inverter to 240vac, sewing motor with belt onto starter pulley. Perhaps ramp-up initial power over a few seconds. all easily do-able, and I have most parts. use 12vdc genset winding to recharge AEG batt w charge control. Min run time perhaps 1hr to recharge batt?
 

jpanhalt

Joined Jan 18, 2008
9,706
Your battery is fine, probably. I have my doubts about a sewing motor and belt drive. Gear to flywheel as @shortbus mentioned will give you a higher reduction than you can get efficiently with a single reduction belt drive. The amount of belt in contact with the smaller pulley gets less with the increase in reduction ratio and decrease in center to center distance. I suspect you will be done in by belt slip. Cogged belt may work. At the very least, I would use a small starter motor for model airplanes or motorcycles.

Here's on model example:

1594772558070.png

That's for a 1.6 in^3 engine (about 26 cc = string trimmer). It's direct drive. With a gear drive, it could handle something considerably larger.
 

strantor

Joined Oct 3, 2010
5,290
Drill rivets out of the pull-start cover, remove pull start, and expose the large nut which holds the flywheel to the crankshaft. Select your least favorite cordless drill, attach appropriate sized socket. Engage cordless drill with socket onto crankshaft nut, pull trigger. Yank cordless drill away from motor (with trigger still pulled) *the very instant* (this is important) the motor fires. Hesitate for more than 100mS and the engine will take your cordless drill away from you and throw it with the power of Thor's hammer in a direction of its own choosing.

If you were to walk my gallery of pull-start small engine powered equipment, you would note that all either have the pull start removed and discarded, or rivets replaced with screws for easy access. I simply refuse to put up with an engine that won't play nice. It puts the lotion on its skin or else it gets the drill again.
 

jpanhalt

Joined Jan 18, 2008
9,706
My 1975 vintage Ariens snowblower as dual pull and electric start. I am glad it does, too.

In other words, the pull start will be a backup when for whatever reason the electric start fails. I would not remove it. As an alternative for my equally old Snapper mower, I just drilled a clearance hole in the shroud and used my electric drill to start it when it is handy. The flywheel disengages from the pull start or visa versa..
 

Reloadron

Joined Jan 15, 2015
5,504
My 1975 vintage Ariens snowblower as dual pull and electric start. I am glad it does, too.
I have a pressure washer like that, I think it's a Husquvarna either 8 maybe 10 HP. Has a 12 V battery but no charging system so after so many starts it needs plugged in. Came with a lousy wall wart which I replaced with a battery tender. Small engines aren't too bad but a 10 HP pull start can be a little hard. :) Not in my 20s anymore.

Ron
 

JMW

Joined Nov 21, 2011
127
Hi,
I'm hoping some of you can save me some time and explain why this is a bad idea. I have a 2kw pull start inverter generator that I'd like to convert to electric start. The obvious solution is to fit a separate starter motor kit and move on but where's the fun in that. Instead, I'm wondering why the generator side of generator/engine pair couldn't be temporarily repurposed into a starter motor to get the engine running before switching back to "generator mode".

At first glance, it would appear that the generator is similar to a brushless motor in that it has coils surrounded by rotating permanent magnets. I have not taken my generator apart to verify this so please correct me if you know otherwise. Anyway, that being the case, would it not be possible to use somet
I had a Honda Civic hybrid.
The main electric motor serve the triple purpose of starting the
Hi,
I'm hoping some of you can save me some time and explain why this is a bad idea. I have a 2kw pull start inverter generator that I'd like to convert to electric start. The obvious solution is to fit a separate starter motor kit and move on but where's the fun in that. Instead, I'm wondering why the generator side of generator/engine pair couldn't be temporarily repurposed into a starter motor to get the engine running before switching back to "generator mode".

At first glance, it would appear that the generator is similar to a brushless motor in that it has coils surrounded by rotating permanent magnets. I have not taken my generator apart to verify this so please correct me if you know otherwise. Anyway, that being the case, would it not be possible to use something like a VFD or an oversized brushless motor speed controller to drive the generator as a motor using a 12v battery? I realize it's likely more complicated than it sounds or otherwise you'd see self starting generators available for sale. Doe anyone have any insight as to why this isn't a thing? Cost, complexity, just won't work?

Thanks!
a VFD or an oversized brushless motor speed controller to drive the generator as a motor using a 12v battery? I realize it's likely more complicated than it sounds or otherwise you'd see self starting generators available for sale. Doe anyone have any insight as to why this isn't a thing? Cost, complexity, just won't work?

Thanks!
Cadillac did it in 1916. Dauphin helicopters for one do it. I know, as I replaced the starter brushes on one. Of course you will need a DC output generator, and then a suitable inverter. I have 3000 watt 48 volt UPS that I would consider parting with, the shipping alone will shut that down.
 

Reloadron

Joined Jan 15, 2015
5,504
@Reloadron

Actually, the starter on the Ariens is 110 V. So, if/when it dies and you are way out in the snow, a pull starter is very appreciated.
Now that you mention it we had a snow blower like that at work. You could plug it in and electric start it but unless you had a long extension cord you had to pull start it once you left the bay door area. :) It was a big two stage blower.

Ron
 
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