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

[rickharris]

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

Diesel can/should run both ways - so if just need to run in stand then can start in prop nut tightening direction to save embarrassing moment as prop flies forwards. PS I ALWAYS put a lock nut on the prop to stop it getting loose.

 

[GailInNM]

We didn't have stuff like surgical tubing in my day.

I can't let you get away with that one John. I was using surgical tubing on model airplanes when you were still a little boy. ;D ;D

Gail in NM,USA

 

[Bogstandard]

Gotcha Gail, so now we know you are not an old fart, but a REAL old fart.

Those materials were most probably about in the early 70's, affording them was the problem at that time. I was so poor, I used to dip my feet in black gloss paint, so it looked like I could afford shoes.

You made do with what you could get your hands on. I think that is where my fetish for recycling came from.

Imagine models being built using aircaft quality high tensile precision machined nuts and bolts, but they were free (except to the taxpayer of the time).

John

 

[Twinsquirrel]

Ignore this if it has already been said,

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

The rubber cup in most commercial starters can be removed from the starters' pulley and flipped 180 degrees giving a flat face with a 10-15mm hole in the center. In my experience the flat face pushed against the prop is enough to turn the engine over and I've rarely had a prop nut come loose but I've only ever run glow engines this way.

David

 

[Twinsquirrel]

Sorry, just been out to the workshop to take some pics (first time I've been out there in about 2 weeks)

Standard cone start,

Prop nut start

 

[Metal Mickey]

Thanks for all the information and advice. I hope to be well enough to get back into the workshop tommorow so I will let you know how I get on........

 

[Metal Mickey]

Just an update really. Not started yet BUT it did fire today...blue smoke and all! However before we get to that I decided to try and start her again today. First I made a starter to run in my drill and after that I stripped the engine down and checked the contra piston, and piston in particular.

According to Ron Chernich's article the piston fit was spot on. i.e. the little end moving to the exhaust ports before stopping. It also showed the taper to be correct as well. Looking at the contra piston though, it was a pretty good fit but not as good as the piston so I made up another and made it fractionally bigger. It did not go into the cylinder liner quite as much as the other before becoming stiff. Indeed I would say this one was more on the very tight side, which is what I wanted.

Cleaned the engine parts again in the ultrasonic ring cleaner (stolen from under the nose of 'she who must be obeyed'!) and reassembled the engine. I must admit I was very surprised at the difference in compression for such a small adjustment. But then, I am new to this game........

Armed with renewed enthusiasm, I followed Ron's start up instructions and screwed the compression screw in, between trying to start her. Unfortunately it became a little discomforting so I decided to use the startering adaptor I made earlier. After three or four more adjustments to the compression screw, the thing fired! Whereas I 'hoped' I felt it fire before, I now know it didn't, because this was completely different. This time there was a puff of blue smoke from the exhausts and a definite smell......(no comments please).

I thought I would go back to the manual method again, as it may be near its setting, but it was too difficult. So I decided to retire before I broke something, and will try again tomorrow.

I may make another piston though, first thing, and see if this will make as much difference and the contra piston did. Its easy to dismantle the engine and change things.

I marvel when dissabling on how few parts there are, compared to how long it took me to make the thing! It is a simple job to disassemble and reassemble so hopefully I can report a more positive result soon..........

 

[NickG]

Sounds promising, yes a new better fitting piston may just do the trick. Although if it fired once, it can do it again, you'll find the setting you need soon! Good luck.

 

[Metal Mickey]

Thanks for the support NickG :bow:

 

[robert1352]

Fantastic work !! Great job!! Can't wait to see it running!!!

 

[Metal Mickey]

Robert, your too kind and it makes two of us that want to see it running! :big: many thanks for the support.

Mike

 

[NickG]

I've just been through the same thing with my first hot air engine, although I'd say yours is a bit more complex!

I was just about to give up despite it showing signs of life, but then I thought I'd dedicate 1 more day to it, turns out it only needed 30 mins of logical thought dedicated to it and got it running!

Your engine fired so I am confident it will run. I bet there are loads of people that can't wait to see it run.

Nick

 

[Jadecy]

For what it's worth...I built a MLA-17 which is a model diesel and very similar in nature to your engine. The biggest issue I had was with the carburetor. I finally did get it running and it ran very well but has always been very tempermental when it comes to adjusting the carb. I never did it but I thought about trying an adapted carb off of a Norvell model engine.

 

[Metal Mickey]

Well it has finally decided to run! It may not have been for long, but run it did! I have given a fuller description on my website www.mikes-models.com if you are interested and a SHORT video here....

[youtube=425,350]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/sG7nm-SaOGg&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/sG7nm-SaOGg&hl=en&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" width="425" height="344"></embed></object>[/youtube]​

The answer was the new piston and whilst it has not run for long, I now know it will, so its more tinkering with the settings. The trouble is the back doesn't match the needs of the engine! I don't want to use the drill starter as it does fire up OK and I would be worried it kick out.......so I will have a go over the next few days and get it running continuously......

 

[NickG]

Congratulations, that's fantastic. A bit of tinkering is all that's needed now!

Nick :bow: ;D

 

[Metal Mickey]

Thanks ever so much. I know its daft but its surprising how much enjoyment I felt when it first fired! Well shock really.

 

[CrewCab]

Nice one MM ............. sounds as good as it looks too 8)

CC

 

[Metal Mickey]

Thanks ever so much, I wonder how a smaller prop would sound? Does anyone know?

 

[Divided He ad]

Nice.... So very close to having it take off with the bench

Bet you are a happy guy right now..... Are people are talking to you and all you can see and hear is that little beautie? (and they're wondering why you have that permanent little smile on your face ;D )


Good stuff Mike.



Ralph.

 

[Metal Mickey]

Thanks Ralph, I will be able to get on with the refurbishment of a Myford ML7 lathe and the 2" scale traction engine........I must admit I am looking forward to next year so I can start on the 15cc Seal 4 cylinder petrol engine!

Oh happy days, oh happy days...... :big: :big: