Economy Hit & Miss Engine Build.

[Anonymous]

Posted by Nick_G on 03/03/2017 03:30:48:

The steel has arrived for the conrod so it seems logical to make that next.

In the early kits the conrod was supplied as a flame (laser?) cut blank. I didn't get one in my kit, and it took a lot of argy-bargy to extract it from the supplier. Having received the blank it was thinner than the finished size on the drawing. So I binned it and hogged it out of hot rolled steel.

Andrew

[Ian S CParticipant @iansc]

Coleman fuel contains a mixture of Cyclohexane, Nonane, Octane, Heptane and Pentane. Octane rating is 50% / 55%, there is no Naptha in it

Ian S C

[JasonBModerator @jasonb]

Probably bad spelling on my part its a Petrolium Naphtha product eg a mixture of hydro carbons.

see wiki and the wiki for "white Gas" as it is often known (option 1)

Edited By JasonB on 03/03/2017 12:12:23

[Neil WyattModerator @neilwyatt]

Posted by Ian S C on 03/03/2017 12:00:17:

Coleman fuel contains a mixture of Cyclohexane, Nonane, Octane, Heptane and Pentane. Octane rating is 50% / 55%, there is no Naptha in it

Ian S C

Ah a mixture of flammable hydrocarbons! Sounds like naptha

The trouble with 'naptha' is it is just a vague word for readily burnable oil l. I've always thought of it as an all-inclusive word for more volatile oils like petrol, diesel, paraffin and maybe white spirit in contrast to vegetable and lubricating oils.

Neil

[Martin CottrellParticipant @martincottrell21329]

Nice progress Nick! How did you produce those lovely smooth curved corners on the crank webs?

Martin.

[Nick_GParticipant @nick_g]

Posted by Martin Cottrell on 03/03/2017 21:14:26:

How did you produce those lovely smooth curved corners on the crank webs?

Martin.

.

I would 'like' to say I am a demi-god with a file. But I would be lying .!

The truth is they are courtesy of an ARC product in the form of :- **LINK**

If I had done them freehand they would have looked like a well chewed wine gum.

Nick

[Martin CottrellParticipant @martincottrell21329]

Posted by Nick_G on 03/03/2017 22:11:42:

Posted by Martin Cottrell on 03/03/2017 21:14:26:

How did you produce those lovely smooth curved corners on the crank webs?

Martin.

.

I would 'like' to say I am a demi-god with a file. But I would be lying .!

The truth is they are courtesy of an ARC product in the form of :- **LINK**

If I had done them freehand they would have looked like a well chewed wine gum.

Nick

Ah yes, hadn't thought of using one of those! I thought maybe you had rounded them off on a belt sander but they looked too uniform to have been done like that freehand. All looking fabulous so far, will be an impressive engine when finished!

Martin.

[Nick_GParticipant @nick_g]

.

I am on with making the conrod. ………… It's taking ages as there is a lot of metal to carve away. Getting close to the shape now but getting the 'jitters' at each new machining section as I have a lot of time invested in this part and to make a bad cut now would be ……………. Bad.!

Anyway. The cast iron casting for the cylinder / water hopper turned up today. Postman remarked that everything I seem to have delivered is heavy.

Nick

[Michael GilliganParticipant @michaelgilligan61133]

That 'looks the business' Nick

MichaelG.

[Nick_GParticipant @nick_g]

Posted by Michael Gilligan on 07/03/2017 19:30:26:

That 'looks the business' Nick

MichaelG.

.

I just wish they would not have letters or numbers on the castings as I have to grind them off.!

Nick

[JasonBModerator @jasonb]

I hate that too, often done with a Dymo lable, suppose it helps the foundry keep track of patterns and castings. Could so easily have put that number on the push rod pad where it would get machined off.

[Ian S CParticipant @iansc]

Why take the numbers off, full size motors have casting numbers on them?

Ian S C

[JasonBModerator @jasonb]

If the number is not a scale representation of the originals then I take them off, some do replicate the original number so in my case they stay. I have even been known to add lettering/numbers but i try to do it to scale not stick a dymo lable on

[Ian S CParticipant @iansc]

I see what you mean with the number on the hopper opening, it looks likely to be a Dymo stick on, I was initially looking at the letters ECH on the side.

Ian S C

[Nick_GParticipant @nick_g]

.

The conrod.

I eventually got 2 pieces down to the major size required and drilled and tapped. The big end cap is a little longer as I want to turn a section in the lathe and then shorten it to remove where the live centre recess has been. – This rounding is not on the original drawing as it's shown as just a block. I thought it would look a bit better.

Decided to get the holes in each end while it was all a uniform shape and simple to grip. This is the first time I have used a boring head in a mill but there was no drama.

Checked the size of the split bearing (made previously) that is still soldered at the joint.

Then split it and checked it against the big end it's self. – Mmmmmm, twas a little tight. Not much, so had to lap the 2. A conversation with Jason gave me advice on the best way to do this.

Over to the lathe for that rounding shaping I mentioned.

Milled the sides down to the required width.

Then milled in the roundings for the taper of the rod. – By now I was getting concerned of doing something stupid and ruining a part that by now I had invested considerable time into.

This concern reared it's head when it came time to cutting the recess groove along the side of the rod. It should be following the line of the rods taper. But I ran out of balls.! I admit it would look better so I really should have grown an extra pair and gone for it.

Milled into the edges to form the taper and round off the little end.

Made some proper studs from 6mm silver steel and shortened the bearing cap to length.

I still have to make the PB bearing for the little and and drill in some oil holes etc. 

I will remove all the tooling marks and give it a polishing when it come time for final, final, final assembly. That way I will hopefully not do my normal trick of bashing, dinging and dropping totally finished parts during the rest of the build.

Nick

 

Edited By Nick_G on 10/03/2017 10:46:12

[JasonBModerator @jasonb]

Looking good (and big) Nick. When you do the next one remind me to tell you the easy way to get that tapered recess to follow the outside of the rod.

J

[Anonymous]

Looking great.

I didn't round the big end corners on mine; didn't think of it. But I did mill the flutes parallel to the sides. I can't remember the precise details but it involved a box table and the horizontal mill, plus a T-slot cutter that looked rather lost on the mill.

Andrew

[Nick_GParticipant @nick_g]

.

Thanks for the kind words people.

Nick

[Willliam PowellParticipant @willliampowell36769]

Enjoying watching the build. Nicely done..

[MalcBParticipant @malcb52554]

Hi Nick,

Have to say am very much liking the progress to date. Think you are doing fine job with your machining.

Its my next project after finishing off one or two things, as I ordered the alloy kit from them at last years Doncaster show, along with the gears already cut etc. Hope to start shortly and this will help considerably and set high bench marks by the look of things.

Soldering the joints on split bearings can be a little hit and miss on the final diameters once split. If you put/use just 0.0010" at each joint that would give you 0.0020" on peripheral length, divided by pye would mean that when the tinnning/solder was completely removed after splitting both the original machined O.D. and I.D. Would reduce by 0.0006" and more than that pro rata if the solder/tinning is thicker than 0.0010". Not easy to control.

I follow with great interest.

[Nick_GParticipant @nick_g]

.

I have spent the last few days doing a 'mish-mash' of several things not really concentrating on one particular area or part. i.e. making studs, rounding bearing caps and part finishing the cylinder liner etc. – This was most;y due to be having to build up width of the tops of the crankshaft pedistals as they were shy on width of about 1.5mm once I milled out between them to allow the crank webs to be able to pass. I did this with JB weld in several layers, each of these taking 24 hrs to cure. …………… Andrew Johnsons solution would have been the better option had I not already made the main bearings.

Milled to give clearance for the webs to rotate. The lack of metal on the outside of the bearings can be seen.

Started to build up the lacking width with JB weld.

Decided to start the outside of the cylinder liner. So went to my mates workshop to put a hole through the solid cast iron blank. This was 38mm and the bore will end up at 42mm.

So first made a stepped aluminium mandrel to 38mm to support at the tailstock end while I machined the outside.

Thus :-

There are 3 different diameters to the liner. The smallest being 50mm (bore will be 42mm)

Rounded off the crankshaft end as a short section will protrude and be visible once it's in the hopper and I will not get the chance to do it easily again.

Parted off to the correct length.

Bearing cap corners rounded and a few of the studs I made. – The thickness of about 1.5mm of JB weld build up can be seen. (damn tuff stuff when it's properly cured)

Had a delivery from The Engineers emporium of parts. – They do a very good deal on them if they are ordered as a batch. I was going to have a go at cutting gears myself for this engine but was not really worth it with the deal by the time good quality cutters had been bought.

Could not resist having a little layout play to get the general feel of things.

Nick

[Nick_GParticipant @nick_g]

.

Decided to do a little on the timing govenor plate and gears. – So spent a while drilling out the plate, boring gear centers, making PB bearings and shafts.etc.

The plate was supplied laser cut. Nice.! But the edges where it had been cut were as hard as the hobs of hell.

THEN LOOK. – This is the 3rd time today I have done this.!!!! – I never usually do this at all. Then I do it 3 times in as many hours. – Time to call it quits for a while I think.

I have a large angle plate now. borrowed from a friend so I can bore out the base to accept the main bearings. So I will start that with a fresh head. – I really cannot afford time wise and certainly not financially wise to make a dogs danglers of that bit.

Nick

[Nick_GParticipant @nick_g]

.

After a break it was time to carve out the base to accept the main bearing.

The squareness of the casting in the important areas was checked and adjusted until I was happy. One of these was checked with the laser indicator.

Castings were step drilled in stages until I got to a 20mm drill.

Then using a boring head in enlarged to the required 26mm

And the main bearings test fitted. – They did.!

Then the moment of truth in seeing how the crankshaft fitted. – Rotating smoothly but without any play.

I still obviously have much to do. But getting the bearings in means things are starting to come together and I can now establish the final positions of much more. It's actually starting to look like an engine.!

Nick

[JasonBModerator @jasonb]

Looking good Nick. .

Now we must get you to show some self control and not be in such a rush to play with your bits. Think I would have tried to resist the temptation and machined the flat for the timing plate at the same setting to keep things true and relative to the crankshaft ctrs. This would also save having to set the whole thing up again in the same position

 

J

Edited By JasonB on 19/03/2017 07:43:29

[Nick_GParticipant @nick_g]

Posted by JasonB on 19/03/2017 07:27:48:

and machined the flat for the timing plate at the same setting to keep things true and relative to the crankshaft ctrs. This would also save having to set the whole thing up again in the same position

 

 

.

The setting up again is not an issue really. – 10 mins, a cup of tea and a cigg.

The main reason I did not do it at the same time is I need to get the position of the driving gear on the crankshaft to give me the plate recess depth as it's not on the drawing. (that I can see) Also throw into this that I had to increase the width of the pedistals at the top which I think will be a factor upon the plates depth.

Having said that there is a spacer (part 13) that goes over the crankshaft that sits between the side of the crank bearing and the driving gear. That's width could be adjusted so that it and the gears on the timing plate sit nicely together.

Nick

Edited By Nick_G on 19/03/2017 09:46:12

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