Micro 12VDC Generator with a Cox .049 Sure Start Diesel Engine

for more power you need more kerosene
the ether only makes it run hotter

i use 1-1-1
and no boosters
my engine is direct drive
and has more then enough power to start and run with it

i would decrese the ether to 25% and increse the kerosene
and for starting use a 75% ether 25% castor mix (as so i am told on a other forum)

my engine just starts after the right choke even on a 7.2V battery (witch is almost to weak to pull it trough the compression)

robot797 wrote:for more power you need more kerosene
the ether only makes it run hotter

i use 1-1-1
and no boosters
my engine is direct drive
and has more then enough power to start and run with it

i would decrese the ether to 25% and increse the kerosene
and for starting use a 75% ether 25% castor mix (as so i am told on a other forum)

my engine just starts after the right choke even on a 7.2V battery (witch is almost to weak to pull it trough the compression)

Thank you for the start up fuel of 75% Ether and 25% Castor Oil. This says a lot.

You have chosen the right mixture of 1 to 1 to 1. You get good power and good protection. You can afford this because you use a battery start although the battery is not of high voltage and can only overcome the compressions.

With a spring start one must not only ignite the fuel immediatelly but the engine must have enough power to go through the next compressions and ignite. This is difficult with a spring start.

After your input, I will definitely use more Ether.

I wish I have a pull start or a handle crank start. I tried to use a drillcas a starter but unsuccessfully.

For your setup, another way to start your engine may be to have an electric dril with a wheel of some sort to touch and rotate your flywheel. This is as a secondary way to do the job. Your battery start up is fantastic.

Can you find some 12V motorbike or a tiny size car battery to start thevengine as opposed to the 7.2V battery you currently use?

i wanted to keep it portable
do i chose a 7.2V battery
i have bought a 8.4 just to test if it is easyer

and when i have my buck converter i can finaly do some power tests

my generator puts out 16-30V and i want a constand 12V

i will also place a ntc inline with the engine
this way the load gets applyed slowly instead of instand

StevenStanleyBayes wrote:Yes. I am to be blamed. I screwed up the fuel.

Regardless. Managed to start the engine with different settings but without the dynamo. The engine worked perfectly with the new fuel and allowed for a wide range of control by all three controls.

However, the system could not start with the dynamo because of the 2 to 1 pulley ratio, 2 for the engine pulley and 1 for the dynamo.

The dynamo puts a big load to the engine which the engine cannot overcome at start. Still managed to start the system but for a few seconds only. Was unable to sustain and I was unable to react quickly to switch the electrical load.

Considering I have to run the dynamo with 4 to 1 pulley ratio,  even higher, 6 to 1 welcome, I am disillusioned and I am not sure I would be able to ever start the engine with the dynamo. Will see but looks impossible now.

I was reading this thread weeks ago, where you mentioned treating the belt with some type of lube to slip "initially".. then grab. Maybe a "wax" would work? Maybe even a crayon? A crayon or small tapered candle could possibly be rubbed on the belt without removal.. and would burn-off after a few seconds of running?

robot797 wrote:i wanted to keep it portable
do i chose a 7.2V battery
i have bought a 8.4 just to test if it is easyer

and when i have my buck converter i can finaly do some power tests

my generator puts out 16-30V and i want a constand 12V

i will also place a ntc inline with the engine
this way the load gets applyed slowly instead of instand

What is an NTC?

A good dynamo will be able to give you 12VDC with some load when you get 16 to 30V without a load. Your dynamo looks big and powerful as well as looks like there are internal gears to reduce the RPM at the expence of torque.

You may wish to lower the RPM by reducing the compression, then to put a load, then to increase the RPM thus increasing the voltage thus the power slowly. This is without a regulator or with a regulator before regulation.

With a rlossless egulator which always regukates, you may wish to increase the RPM before applying the load.

I have found the engine works more consistently at low compression when load is applied ( during a stress ) and then you can increase the compression after the initial stress.

The flywheel will definitely help you overcome the load stress as well as the inertia of the dynamo.

Because you have an electric start, you can even start the engine with the load applied to the dynamo. This way, the initial load stress will be covered by the electrical start.

You can also put the batteries in series to give you 15.5V.

roddie wrote:

StevenStanleyBayes wrote:Yes. I am to be blamed. I screwed up the fuel.

Regardless. Managed to start the engine with different settings but without the dynamo. The engine worked perfectly with the new fuel and allowed for a wide range of control by all three controls.

However, the system could not start with the dynamo because of the 2 to 1 pulley ratio, 2 for the engine pulley and 1 for the dynamo.

The dynamo puts a big load to the engine which the engine cannot overcome at start. Still managed to start the system but for a few seconds only. Was unable to sustain and I was unable to react quickly to switch the electrical load.

Considering I have to run the dynamo with 4 to 1 pulley ratio,  even higher, 6 to 1 welcome, I am disillusioned and I am not sure I would be able to ever start the engine with the dynamo. Will see but looks impossible now.

I was  reading this thread weeks ago, where you mentioned treating the belt with some type of lube to slip "initially".. then grab. Maybe a "wax" would work? Maybe even a crayon? A crayon or small tapered candle could possibly be rubbed on the belt without removal.. and would burn-off after a few seconds of running?

These are excellent ideas. Car wax may help. Castor Oil does not help much because the pulleys start to grip very quickly. Standard grease for cars may also help.

ah that is the awsome part
it is a ungeared engine


when used as a motor 48V 11000 rpm custom selected just for that spec

and for my regulator
i want to regulate my output so that the rpm can stay the same

and for the ntc it is just a negative temperature coefficient resistor

high resistance when cold
low resistance when hot
and becaus they are selfheating
when pulling amps the resistance drops and you get a slow load

robot797 wrote:ah that is the awsome part
it is a ungeared engine


when used as a motor 48V 11000 rpm custom selected just for that spec

and for my regulator
i want to regulate my output so that the rpm can stay the same

and for the ntc it is just a negative temperature coefficient resistor

high resistance when cold
low resistance when hot
and becaus they are selfheating
when pulling amps the resistance drops and you get a slow load

This resistor will help. Another way is to achieve tge same with a delay circuit : a transistor will switch the output off and will wait for a capacitor to charge to release the output. This way, any sharp change will close the transistor which will slowly open untill the capacitor is fully charged.

To use this, the dynamo must give a stable output which can be achieved with a large capacitor in parallel to the dynamo which will also cover for the initial load to an extent. Too big capacitor may blow the dynamo up. Although circuit for prwvention of this is possible, similar to the described, best choose a capacitor which will not overload the dynamo during the initial as well as quick load change.

Is it possible to use a centrifugal clutch from an RC car?

yea
that would be posible
if there was a type that had a 3.17mm axle hole

Cribbs74 wrote:Is it possible to use a centrifugal clutch from an RC car?

I did not know such exist but, yes, a centrofugal clutch would probably solve most of the problems.

Pretty sure the Cox/Kyosho cars ran clutches on the .049's

There are some on Ebay. Even if the hole is/was bigger it would be easy to fit a spacer.

Cribbs74 wrote:Pretty sure the Cox/Kyosho cars ran clutches on the .049's

There are some on Ebay. Even if the hole is/was bigger it would be easy to fit a spacer.

Thanks.

Had a quick look. Yes, thank you all for the information : the real way to make this project is with an RC car clutch and flywheel. The .049 Cox Kyosho flywheel and clutch are the best. Others may be OK too. An important consideration is the RPM at which the clutch engages. Also, looks like there is a gear wheel coming from the clutch and I must put a pulley there, I hope, as mentioned, there will be a possibility for an axel to come out of the gear wheel to attach a pulley to.

The problem is these cost a lot of money but they are worth. Hopefully, I would be able to get some, I do not know when and where. In case anyone has and want to sell, please inform.

While I was looking at the running engine and the belt, I came up with a design of an easy clutch system, the easiest I can think of, yet not as easy when made in a home environment. Two freewheeling pulleys have the belt round on them. They are either behind the engine or behind the dynamo. The belt goes over them and does not touch the main pulley of, say, the dynamo. The axels of the two freewheeling pulleys can travel on two rails and the axels are connected to each other with a connecting rod. When the two pulley system is pulled, the system goes even more away from the main pulley ( of the dynamo ). When the system is pushed, the belt goes closer to the main pulley. When pushed more, the belt starts to touch the main pulley and, hopefully, slide over the main pulley. When pushed more, the belt stops sliding over the main pulley and starts to engage the main pulley. A spring may ensure the main pulley will stay engaged after the system is released.



The picture depicts the simple system without the spring. Looks like a slingshot clutch.

Simple or not, even this may be difficult to make in a home environment.

For now, I would concentrate on belt holder ( s ) which will hold the lower portion of the belt, i. e., the belt would slide into a holder's circle like a thread into a needle, hopefully, without touching. Thus, the holder would become a guide through which the belt is guided. This would allow to use a lower tension belt with grease and the lower portion of the belt would not vibrate so much to drive the belt out.

Meanwhile, I may try to make the same clutch idea, yet a lot simplified. I may use thicker Copper wire, the same as for the guides, to replace the clutch pulleys with a guides which can bend. Thus, I can bend the guides to move the belt away from the engine pulley and start the engine. Then, I can bend the guides to bring the belt closer to the engine pulley until the belt slips and then engages. I may even try to do this with one steady guide and only one which bends. I am not sure whether this would work but this is the simplest idea I have and may try to see.

Any other simple idea is welcome, so, please, advise.

Hi Stephen, I realize it's expensive to source items that may not work for your application.. and difficult if not impossible to make at home because of the lack of proper tools.

Have you thought about trying "cone" or "stepped" pulleys? I'm not sure that this would solve your immediate concern.. but it would allow for easily altering the ratio of engine rpm vs. dynamo rpm. You might be able to make them using hardwood discs of graduated diameters, stacked together? Perhaps a cone-pulley set could be configured as a sliding clutch?

Here's a link that my be useful

http://chestofbooks.com/crafts/scientific-american/Recipes/How-To-Design-Cone-Pulleys.html#.VS4zYRtFBMs

roddie wrote:Hi Stephen, I realize it's expensive to source items that may not work for your application.. and difficult if not impossible to make at home because of the lack of proper tools.

Have you thought about trying "cone" or "stepped" pulleys? I'm not sure that this would solve your immediate concern.. but it would allow for easily altering the ratio of engine rpm vs. dynamo rpm. You might be able to make them using hardwood discs of graduated diameters, stacked together? Perhaps a cone-pulley set could be configured as a sliding clutch?

Here's a link that my be useful

http://chestofbooks.com/crafts/scientific-american/Recipes/How-To-Design-Cone-Pulleys.html#.VS4zYRtFBMs

I have not thought of cone or stepped pulleys but they are a good idea. The problem is I do not have such an installation accuracy so the belt can be positioned ay a given place exactly.

I have thought of a bicycle style of pulleys but I am not sure whether I have enough room.

I may attempt the simplest thing : to manually hold and slowly slip the belt over the engine pulleys by using 2 Copper wires. The problem is I am not sure whether the belt would slip over the Copper wires.

Another option may be to mount the dynamo in a sliding tray. Moving the dynamo pulley away from the engine pulley would tension the belt. You could figure out how to lock it in the running-position easy enough. Possibly slot the tray or the base, for a machine-screw/wing-nut? This would also allow for belt-stretch over time.. or trying different size/length belts.

roddie wrote:Another option may be to mount the dynamo in a sliding tray. Moving the dynamo pulley away from the engine pulley would tension the belt. You could figure out how to lock it in the running-position easy enough. Possibly slot the tray or the base, for a machine-screw/wing-nut? This would also allow for belt-stretch over time.. or trying different size/length belts.

Yes. This was the original idea : like a car. Either this way or another movable tension pulley. Just like the two options of a car. This may be the easiest way. Thank you!

Please, keep giving ideas. Your ideas have been great so far.

You're Welcome Stephen. I enjoy building things too. If you know of the movie character "Caractacus Potts"... then you'd know my personality!

roddie wrote:You're Welcome Stephen. I enjoy building things too. If you know of the movie character "Caractacus Potts"... then you'd know my personality!

Well, I do not know this character but I know another one from another movie who has designed engines for Chrysler and now flips burgers at McDonalds. : )

StevenStanleyBayes wrote:

roddie wrote:You're Welcome Stephen. I enjoy building things too. If you know of the movie character "Caractacus Potts"... then you'd know my personality!

Well,  I do not know this character but I know another one from another movie who has designed engines for Chrysler and now flips burgers at McDonalds. : )

An easier way to make cone pulleys is from conical wine cork. Such are sold in the local automotive stores.

In case I am able to have a large belt which stays inside the pulleys' chanels and does not jump over when not engaged, then a simple clutch can be made of a bendable Copper wire with a freewheeling pulley which would engage the belt when bent.

StevenStanleyBayes wrote: In case I am able to have a large belt which stays inside the pulleys' chanels and does not jump over when not engaged, then a simple clutch can be made of a bendable Copper wire with a freewheeling pulley which would engage the belt when bent.

How about using a small wooden spool as an idler-pulley? You could make a music-wire (spring-steel) idler-shaft that locks under a hook when tensioned. Craft stores sell the little wooden spools.