Mills 1.3cc diesel - Plans by Ron Chernich from Model Engine Builder magazine

[SandyC]

;D

Hey MM, super job.

that sure brings back some great memories.... ETHER, PARRAFIN, CASTROL R and AMYL NITRATE...... can't get the last one now, it's illegal...rotten spoilsports  :big: .

I still have a matched pair of MILLS 0.75's (original, not run in) and sequential serial numbers... from way's back in the early 60's.  NO YOU CAN'T BUY THEM  ;D ;D ;D

Suitable fuel can be purchased from 'MODEL TECHNICS' in Shoeburyness, Essex.

www.modeltechnics.com

I would suggest the 2% Nitrate mix for your engine. (they use Isopropyl Nitrate these days and synthetic oils)

Hope this helps.

Best regards.

SandyC  ;D

 

[Metal Mickey]

Hello SandyC a single 0.75cc fetches over £100 on ebay so a matched pair as you describe must be worth at least two and sixpence! Sure you don't want to sell them! Thanks for the link re fuel. I tried to buy some diesel from Model Technics but they told me they only sold to trade and couldn't send any in the post anyway! There is a model shop in Newton Abbot who are trying to get me some but it seems its like gold dust!


Thanks for the comment Twinsquirrel...kind of you. That's one thing this site offers us lonesome modellers....the wife just says " that's a small one". I think she was referring to the engine........

 

[dave e]

Hi Metal. It looks like you're really getting close. Congrats on the beautiful build.

I have read about people using a starting stick. I guess that's simply a stick with some protection that is used instead of fingers? Any experience of using them, and a general description?

I flew RC planes competitively a few years ago. Starting sticks are ok, but the simplest method is to get about a 4 inch long piece of automotive heater hose. Get a size large enough to stick your finger in. If you're fingers are too big for the largest size, it's fine to split it lengthwise. All you do is flip the prop over with your finger protected by the rubber hose. It still smarts a bit if you get whacked, but there won't be blood or missing body parts. If you prefer to use the stick, just cut a length of broom handle about 8 inches long. Put the rubber hose over the business end to protect your prop, and flip away with that.

Also, for a prop that size you need to be sure to check the balance. I hunted around in Google for a couple minutes and was surprised that I couldn't find a nice step-by-step about how to do it. This is about the best I could find. http://www.rctoys.com/pr/2008/08/01/how-to-balance-rc-model-airplane-propellers/. If you look this over and still need help, let me know and I'll try to write up something. Lastly, I hope it's obvious, but the hole in the prop has to be the right size. If it's too big, either get a different prop or make up some bushings for a nice snug fit.

Good luck.

Dave

 

[Metal Mickey]

Sorry Dave e I didn't respond to you email. thanks for the tip re bushes. I checked both props I have and whilst one is fine the second will need a bush! So again thanks for the tip.

Tomorrow I hope to have the engine fully assembled and I found out tonight I have sourced some diesel just a few miles from me....so if all goes well I MAY be able to at least get frustrated trying to start her! Nervous or what......If I do there will be a video on here as soon as possible....if I don't you won't hear from me ever again............ :

Just a couple of photo's of the latest position........

Used the wife's ultrasonic cleaner.........

Some of the dirt that came off......

The parts prior to cleaning further with thinners....

So if the engine don't start... this is my last post..................(or until it does!) :big:

 

[kustomkb]

looks real nice, it'll run.

 

[Metal Mickey]

looks real nice, it'll run.

Oh I do hope so.............. :'(

 

[CrewCab]

It'll run Mickey ............ but on the off chance it don't ............ just pop back here and ask why, help is just a keystroke away 8)

Good luck mate.

CC

 

[Metal Mickey]

Well I thought I would give an update on progress. Its some good news - bad news.........

The good news is the engine is finished and I have also completed (nearly) a test stand (see photo's below)

and

and

Now to the bad news.....After making a couple of adjustments (which included making a new contra piston) the engine is now finished and the long job of trying to find the best settings to give it life has started. The bad news is that due to my disability, the energy required in flicking it over, does me no good so the time I can spend trying to start her is severely diminished! Something I never ever considered.

On a more positive note however is I believe I am getting near to the correct compression setting......time will tell...so I spent the rest of this morning tiding up the workshop and getting the Fowler Traction engine bits in some sort of order to start making progress on her build. My targets for this year requires me to get her sat on all four wheels and the steam cylinder bolted to the boiler. I have only 3 months of the year left and there is a lot to be done!

On a separate note where does all the time go? Its only another 15 weeks or so till the end of the year (I am away three weeks cruising to the Caribbean :big

 

[GailInNM]

Mike,
Most of the writings on model compression ignition engines say "do not use an electric starter". This is because the high compression ratio makes it easy to get a hydraulic lock. When this happens, a bent con rod or crank pin is the normal result when using an electric starter.

Now that that is out of the way, I sometimes do use an electric starter on compression ignition engines until I get the engine to a reliable starting condition. After the engine is broken in and I learn the engine, one or two flips will fire it up. You do have to be careful however. If you prime the engine in the exhaust port, be sure to turn the engine over slowly 2 or three times to make sure there is no hydraulic lock. In fact, always turn the engine over a couple of times slowly by hand before using an electric starter.

Be gentle with the starter. I use a 12 volt starter. On small engines, I use a 9.6 volt NiCad pack. This helps limit the power some and provides plenty of power. Never increase the compression with the starter running.

I suggest that, due to your disability, an electric starter may be the correct answer for you. If you do decide to use one, I can provide more details on my startup procedures for new engines or engines that have not been run for a while.

Gail in NM,USA

 

[Metal Mickey]

Hello Gail,

Thanks for your post. I appreciate your advice and I will follow it with the cautions you mention. I am sure its close to starting. Do you think if I made up a fitting using two nylon small diameter rods, that would help? Some sort of fork arrangement. That way it may be a little safer?

Mike.

 

[Metal Mickey]

Ignore my last post in regards to the fork thingy. I didn't think it through in regards to if/when it starts it won't disengage! A severe case of ooooppppppssssss :wall: :wall:

 

[CrewCab]

MM ............... much better to sort it out at the "Drawing Board" stage, well done.

CC

 

[GailInNM]

Mike,
I was going to comment on your posts, but you got that figured out rather quickly with out any prodding. Actually, there was a commercial starter that did something like that. It was a wind up spring affair and the posts were folding, so they would fold out of the way when the engine started. I don't know of anyone who liked them.

I think all of the commercial ones now use a rubber cone which can be pressed against a large spinner, or can just be pressed against the prop. I have always just pressed against the prop, and if a small spinner or tapered prop nut ,like you have, is used, it just fits into the recess of the rubber sleeve. The rubber sleeve is replaceable so if it gets chewed up it is only a couple of dollars to replace. Mine needs to be replaced, but just because it is dried out. I have used it for a long time.

The starter I use has not been made for a number of years, but it is similar to the following one by Tower Hobbies that sells in the US for under US$20. You probably have something similar available in your area.

Gail in NM,USA

 

[Metal Mickey]

I was thinking of using some neoprene to make "something" that would have two slots in the neoprene. I will have ago and post the first attempt......... :fan:

 

[NickG]

Good luck, we're all waiting with baited breath!

 

[rickharris]

Hello Gail,

Thanks for your post. I appreciate your advice and I will follow it with the cautions you mention. I am sure its close to starting. Do you think if I made up a fitting using two nylon small diameter rods, that would help? Some sort of fork arrangement. That way it may be a little safer?

Mike.

In my youth - I owned and flew a PAW 1.5 cc diesel - in fact still have the engine although not run for many a year.

My method - which worked for me - Screw in the throttle needle all the way (be gentle) back off (open) 2 full turns.

Back off the compression and turn the prop over to push contra piston up to the stop.

Put finger over air inlet and turn the prop over 2 full cycles to draw fuel into the crank case.

Turn prop until compression is felt and flick with vigour! make sure to pull hand back on each flick and DO NOT put hand/finger back into the spinning prop (it's easy to get into a pattern and not register the engine has started).

if no joy after a few flicks - tighten the compression down and repeat - eventually it will start to cough - your close then. These simple diesels draw the fuel into the crank case and then pass up to the cylinder getting some in there for a start helps.

you can prime the cylinder with a short squirt of fuel from the bottle through the exhaust port = this can give you a quick route to firing and you may well get a few cycles and a chance to adjust the settings.


mind the prop when adjusting the fuel/compression. I agree most "experts" advise against a starter as too much fuel/too much compression can see you shoot the head right off the engine. fingers work and its not all that dangerous - probably less danger than you were in when making it.

Good luck - a suitable model is next to fly the beast - I can guide you to some on line plans

 

[Bogstandard]

Mike,

I think Gail was on about a friction cone starter.

Your spinner is rather small for a commercial unit, so I have done an ideas sketch to show you how it works. Just a piece of rubber tube glued into a holder, and is pushed against the spinner to turn the engine over.
The drawing shows a cut thru, it should be a full circle.

John

 

[CrewCab]

Bit like the Moto GP slave starters, particularly favoured by Ducati, however in this case I think "much smaller" is required as aptly illustrated by Mr BS ;D

John, have I missed a "Crap-O-Cad" update, I see new fonts and better rendition ....... I'll send mi' 50p for the upgrade

CC

 

[GailInNM]

John,
You are right, but you leave the tubing stick out a ways, 3/16 inch or so, and you can press it against the prop without using s spinner. If pressing against a prop nut like Mike's it is easy to loosen the nut if you are not careful. Just use the prop nut to help initial centering. Large natural rubber tubing, like surgical tubing, works better than a stiff rubber like garden hose or neoprene when doing this.
Gail in NM,USA

 

[Bogstandard]

Thanks for that Gail, it is about thirty odd years since I have used a starter. We didn't have stuff like surgical tubing in my day. You used what you could get hold of and hope for the best. Us old farts are like that, try anything once.


You have got to admit Dave, a couple of minutes sketching saves hell of a lot of fingerwork typing it all out, and even then it might not be understood.

Just designing new fonts, but they tend to change the more tired and ratty I get, so a bit unstable yet for an upgrade. You can still send the money though, donations always welcome.


John