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

roddie wrote:A spool can be drilled/bushed to spin on small dia. (.062"/1.6mm) rod.. using common Brass tubing. Having an assortment is something useful for any hobbyist. Craft stores may sell the tubing (K & S brand) or Tower Hobbies sells bags of assorted size cut-offs ("shorts") which are quite useful and inexpensive.

Tower Hobbies tubing link

Tubing will definitwly help but there will still be friction. Tiny bearings are a solution although they also have frictiin yet not as much.

Still, this is an excellent idea for which I thank you. These are also good as hose connectors.

A 0 to, say, 50 Ohm potentiimeter, 50 W in series to the load may allow for a gradual load.

I have not looked for availabity but I know there are high current potentiometers for heaters.

The higher the Ether content the easier to start, the lower the heat amount and the lower the power.

The engine has ti be able to start but also has to give enough power to overcome the load.

Here is the question : has anyone used a higher amount of Ether and how much is the power output?

The lower tension the belt the lower the pull the lower the mechanical load to the engine but the higher the possibility for the belt to jump out bwcause of vibrations.

So, I have installed guides, through which, the lower portion of the belts go. However, I am pesimistic this would work because, when the belt vibrates, the belt touches the guides thes creates a load. This would increase the load to the engine and may brake the belts. To decrease vibratiins, the belt myst not be elastic but I do not have such a belt.

Anyway, I have installed the guides and will try to start the system with 2 to 1 engine to dynamo pulley ratio and will see what happens.

I have also found some grease from a garage around and will grease up the pulley, the belt, the guudes and the dynamo and hope the belt would slip.

As said, I do not think tge guides would workbut I hope so. However, I have been able to start the engine with the sane pulleys and standard fuel, so, I hope to be able to start the engine again in the same circumstances.

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.

So far, after all the good ideas, I think the sliding tray dynamo is the best because no external components are needed. Apart from the difficulty to make this, there is one problem which, I think, is possible to overcome.

Belt is a nasty thing. Even when loose, the belt may touch the rotating engine pulley and vibrate and jump up and down, left and right. To overcome this, belt guides over the pulleys and throughout the belt are welcome. These guides will not be functional during a normal run but will only keep the belt when the belt is released. When tightened, the belt would go the normal way.

This system does not require any external components and, I think, is the best.

Obviously, a car clutch is even better. However, I will leave this opportunity for the future because of the difficulty to find a right clutch and because I do not even know at what RPM the engine starts and to what RPM I need to have the clutch disengaged. In case the clutch engages too early, the engine may not be able to overcome the mechanical resistance of the dynamo. Also, because the Cox Kyosho .049 clutch may be difficult to find, selecting and finding another clutch would be a nightmare. I love the idea and the correctness of the way to solve the problem but I would leave for the future. I am happy to know such a solution is available and I cannot thank enough to the people who have posted this and conversed in regards to this. Also, such a clutch would probably be extremely expensive when new, probably $100 after the mailing charges. I have looked very briefly at eBay and have not been able to find a used one.

In case an adjustable clutch exists which allows for an adjustment of the RPM at which the clutch engages, this would probably be the best solution. While I was browsing, I thought I read something alike but I was not sure.

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)

Sorry, I did not fully respond before. Reducing the Ether to 25% and increasing the amount of Kerosene is a great idea for your setup. This also is a great advantage for your design : straight coupling with preliminarily selected dynamo to match the RPM and load of the engine and, most importantly, electrical start. Because of the electrical start, you can afford to get rid of Ether as much as possible and to use as much power giving Kerosene as possible. As a result, you will be able to achieve much higher power. I have not measured or calculated how much more but, I just think you would be able to get 75W out of the engine provided the engine gives 50W with normal fuel. I expect your dynamo to have more than 80% efficiency at high loads, thus, you would be able to get 60W.

I am not fighting, I am just trying to help by sharing this thought and I would like to be corrected in case I am wrong, so the truth is known : Kerosene burns at higher temperature than Ether and, when you reduce the Ether content and increase the Kerosene content, you would increase the temperature of the engine. A possible decrease may come from the fact you need much lower RPM to achieve a given goal because of the more powerful fuel. Also, you have plenty of power to burn rich or at lower compression which would lower the temperature even more. I do not know which of the two factors will take precedence : whether the increase of the temperature because of the higher burning temperature of the fuel or the decrease because of more power.

In case you run the engine at the maximal RPM, you will get higher temperature but you do not want to go too high because you may shatter the Teflon gasket because of the higher power you get.

At low RPM, you are OK. You mentioned your dynamo gets 48V at 11000RPM. You will probably never need to go so high because you would be able to get 12V at less than or around 6000RPM for most of the loads. Your dynamo is very powerful and you would be able to respond to most loads without a significant decrease of the zero load voltage at these RPM.

Your design is more correct in every single aspect : a better start and much higher power not only because of the dynamo but also because of the higher power fuel you can use.

I so much wanted to use a mechanical start but I am not sure whether I would be able to do so.

I can only hope your dynamo has bearings on all points where the rotor is supported. This way you would get even higher power.

kerosene burns hotter but also slower
so you have a greader power during the whole stroke

and for the dynamo bearings
stock metal bearings
last a lifetime in a printer
will last a little shorter on this engine

and for the heat
i have run the engine at full power
without a cooling fan but with a heatsink
i can hold my hand on the heatsink for upto 20 seconds
and then it gets to hot

so my temperature is kind of okey

robot797 wrote:kerosene burns hotter but also slower
so you have a greader power during the whole stroke

and for the dynamo bearings
stock metal bearings
last a lifetime in a printer
will last a little shorter on this engine

and for the heat
i have run the engine at full power
without a cooling fan but with a heatsink
i can hold my hand on the heatsink for upto 20 seconds
and then it gets to hot

so my temperature is kind of okey

OK. The heatsink does the job. You can still make some indentations on the flywheel for some fan effect but best do not because of the symmetry and balance.

I will still send you some tiny fans which I have tried to use as propellers unsuccessfully because they break but they work well as fans. You do not need to install them but with them you will be able to hold the engine continuously for as long as you wish.

A tiny amount, lower than 5% of cetane booster even not amil nitrate based, will allow you to squeeze even more power from the high content of Kerosene.

A dynamo with ball, cylinder, barrel or any other type of bearings will waste less power. No need to change anything. Your dynamo is OK. Metal bearings are better than plastic.

You may wish to fill your dynano with nonconductive grease and or Castor oil. When rotated, grease would spread everywhere, most importantly, on the metal bearings. This will reduce the power loss and may allow you to decrease the amount of Ether.

I think I have read somewhere people are able to manually start RC diesels with 20 %of Ether. I am not sure whether Cox or other. You can even go lower than 20% with the electric start.

Your project is very important for another reason : looks like I would not be able to succeed with a manual start and this dynamo even with a clutch. But you will, based on the preliminary results you have posted. Thus, we will have one fully functional generator which is the goal I have tried to achieve.

You have also mentioned a regulator. Is this just an electrical regulator or the regulator controls the engine to ensure 12VDC?

hi
good idea of the oil for the dynamo
maybe i can redirect the exhaust into it

and for the regulator
http://www.ebay.com/itm/LM2596-DC-DC-Adjustable-Buck-Converter-Step-Down-Module-Power-Supply-1-23V-30V-/261826975246?pt=LH_DefaultDomain_2&hash=item3cf61a960e

i could also use a buck/boost converter combo
but i think my voltage is high enough most of the time

robot797 wrote:hi
good idea of the oil for the dynamo
maybe i can redirect the exhaust into it

and for the regulator
http://www.ebay.com/itm/LM2596-DC-DC-Adjustable-Buck-Converter-Step-Down-Module-Power-Supply-1-23V-30V-/261826975246?pt=LH_DefaultDomain_2&hash=item3cf61a960e

i could also use a buck/boost converter combo
but i think my voltage is high enough most of the time

Please,  do not redirect the exhaust anywhere near the dynamo and keep as far away as possible. The exhauset contains unburned fluids which are electrically conductive and will blow your dynamo up.

The IC is OK. Will not allow much more than 36W. Lossless,  around 90% efficiency. Requires an inductor which I hate but is OK.

I used a combined step up and down regulator which would take anything from 3V to 18V and make 5V or programable output voltage at 50mA but can be boosted by a MOS transistor to give higher currents. Inductorless. Forgot the IC and manufacturer. Emailed to possible manufacturers. No answer so far.

You can probably put 2 in sequence or parallel with diodes. You can adjust the voltage to 6V or 12.7V.

it seems that your not an electrical guy

so i will explain

the buck converter i did send you has the inductor on board and it is a complete funktional unit that can deliver 3A max

all voltage above the voltage you want gets turned into extra amps

so that is cool

and a boost buck converter can be gotten in diverent forms
you say only 50ma
this is not true
there are 10A versions
http://www.ebay.com/itm/DC-DC-Boost-Buck-adjustable-step-down-Up-Converter-XL6009-Module-Solar-Voltage-/171754383577?pt=LH_DefaultDomain_0&hash=item27fd5be8d9
this is a 3A version

you set the output and it makes it regardless of the input (as long as it within the marges)

robot797 wrote:it seems that your not an electrical guy

so i will explain

the buck converter i did send you has the inductor on board and it is a complete funktional unit that can deliver 3A max

all voltage above the voltage you want gets turned into extra amps

so that is cool

and a boost buck converter can be gotten in diverent forms
you say only 50ma
this is not true
there are 10A versions
http://www.ebay.com/itm/DC-DC-Boost-Buck-adjustable-step-down-Up-Converter-XL6009-Module-Solar-Voltage-/171754383577?pt=LH_DefaultDomain_0&hash=item27fd5be8d9
this is a 3A version

you set the output and it makes it regardless of the input (as long as it within the marges)

Yes. These are switching power supplies. Hoever, the one you have chosen does require an external inductor.

The one I have used does not and can provide any current you want with an appropriate external transistor. The transistor consumes 0.1V.

Neither of these consumes a lot of power hence 90% eficiency : 90% of the input energy goes to the output.

You will also need a heatsink for the one you have chosen.

no it has a onboard inductor like all othe chips

it is the black squar with 470 on it (470uH)

it does not need a heatsing becaus it is designed for3A max
if i would heve bought the 5A version it does need a heatsink

robot797 wrote:no it has a onboard inductor like all othe chips

it is the black squar with 470 on it (470uH)

it does not need a heatsing becaus it is designed for3A max
if i would heve bought the 5A version it does need a heatsink

External inductor is required and they even list the manufacturers and numbers. This is the problem with this type of switching power supplies. The one I have used does not.

then you have weird buck converters
i only use the complete units
they need no parts and have a input and output

the title of the link does say the type number of the part
but it does not mention it is a ready to use board
no need for external transistors/mosfets and resistors-inductors

StevenStanleyBayes wrote:

robot797 wrote:no it has a onboard inductor like all othe chips

it is the black squar with 470 on it (470uH)

it does not need a heatsing becaus it is designed for3A max
if i would heve bought the 5A version it does need a heatsink

External inductor is required and they even list the manufacturers and numbers. This is the problem with this type of switching power supplies. The one I have used does not.

See the quote thereafter and the typical schematic in the spec.

An iductor is required. You best use a heatsink regardless of whether required which I am sure but I did not check the documenyation. Otherwise you will burn your IC very easily. 3A is a lot of current even for a switching power supply. This is also why they sell them in heatsink friendly packages. Remember alsi the spec may tell you they are OK AT ROOM TEMPERATURE. When you add the heat from the ambient and the engine, you may go to more than 60 degrees Centigrade.

Here is a quote from the technical documentation of the component on the first of your regulator IC's : LM2596 :

"  

A standard series of inductors are available from several different manufacturers optimized for use with the LM2596 series. This feature greatly simplifies the design of switch-mode power supplies.

"

again there is an inductor onboard

pleas klik the link
you will see a pcb not a chip
and then you get what i am saying

and here is a screen of the link
as you can see its a ready to use pcb
with uses the pcb as a heatsink

i dont want to fight about it


i am right and you are right
but i aint got enough time to design my own buck converter

StevenStanleyBayes wrote:

StevenStanleyBayes wrote:

robot797 wrote:no it has a onboard inductor like all othe chips

it is the black squar with 470 on it (470uH)

it does not need a heatsing becaus it is designed for3A max
if i would heve bought the 5A version it does need a heatsink

External inductor is required and they even list the manufacturers and numbers. This is the problem with this type of switching power supplies. The one I have used does not.

See the quote thereafter and the typical schematic in the spec.

An iductor is required. You best use a heatsink regardless of whether required which I am sure but I did not check the documenyation. Otherwise you will burn your IC very easily. 3A is a lot of current even for a switching power supply. This is also why they sell them in heatsink friendly packages. Remember alsi the spec may tell you they are OK AT ROOM TEMPERATURE. When you add the heat from the ambient and the engine, you may go to more than 60 degrees Centigrade.

Here is a quote from the technical documentation of the component on the first of your regulator IC's : LM2596 :

"  

A standard series of inductors are available from several different manufacturers optimized for use with the LM2596 series. This feature greatly simplifies the design of switch-mode power supplies.

"

The trick of the one I used was : the IC does only the switching job and the transistor : the power job at no consumption. In case you can find this you have the perfect arrangement and reliability.

its already done

robot797 wrote:

its already done

I am not fighting but trying to help. I did not know you are using a ready board, sorry. In case you are, no problems. Use any. Even when burns, they are so inexpensive, you can put another. Since they are just a dollar, you may get a few of them just in cases.

I think you would be able to get 5A,12V with your design. A good idea is not to go to the top of the possibilities, though, so 3A is OK.

robot797 wrote:no it has a onboard inductor like all othe chips

it is the black squar with 470 on it (470uH)

it does not need a heatsing becaus it is designed for3A max
if i would heve bought the 5A version it does need a heatsink

robot797 wrote:again there is an inductor onboard

pleas klik the link
you will see a pcb not a chip
and then you get what i am saying

i tried to tell you

if you just had done kliked the link

but that is why i didnt wanna fight about it (yea i know it is a discusion)