1895 Otto Vertical Gas Engine

[Jo]

I do have a sack I put all teh swarf and scrap metal in that I could introduce him to

It was once someone's pride and joy, they put their heart and soul into making it  . Ok so they were a bit on the optimistic side  you should never start with one of those engines but that is no reason to commit a model engine to the recycling bin 

Jo

[Jo]

Lunch has been cancelled: Both are staying with their current owner 

Jo

[RayW]

Photo CD received from Engineers Emporium looks as if it will be of some help, as it does, at least, show how most of the parts fit together and how to fabricate some of the smaller, more intricate components.
Made a start today on the base casting as this is the easier to hold and machine.The underside was pretty flat already so just needed a light sanding on a surface plate to finish it. Tidied up the edges of the base with a file to remove excess flashing and milled the top to reduce the overall height to the correct level. Next step will be to machine the faces for the inlet and exhaust valve housings

[RayW]

I have now completed the boring out of the base casting to accept the cylinder liner and machined the faces for the inlet and exhaust housings.The top face of the casting needs to be drilled with seven holes to attach the upper yoke casting which supports the crankshaft. I had intended to use my rotary table for this, but the combined height of the table and casting was too high for my mill, so the alternative was to make a drilling jig as shown in the photo.
Also shown is the cylinder head which locates in a recess in the base.

[RayW]

Completed the cylinder liner, but not totally happy with it, so debating whether to remake it or not. There is a shallow, but visible, smooth groove near the top end of the bore which has not completely honed out. As far as I can see, it is well above the level reached by the piston rings, so will probably have no effect on compression, in which case, I may well decide to live with it.
On a more positive note, I made good progress today boring out the top casting to fit over the cylinder. With top and bottom castings assembled, and with the cylinder in position, it is actually starting to look like an engine!

[Dave Otto]

Great progress Ray.

Thanks for the update; it is starting to look like an engine.

Dave

[b.lindsey]

I'm still following alone too Ray, nice progress and thanks for the update!!

Bill

[RayW]

Horrible wet weather here for the last couple of days so the ideal excuse to disappear to the workshop for a few hours!
I ended up making a new cylinder liner after all, having purchased a new piece of pipe from Engineers Emporium(EE) and I am much happier with the bore on this one.
I have also finished the crankshaft, which has turned out pretty well.The shafts and main journal are silver soldered to the webs, with the main journal also being pinned with hardened steel pins.
Next step is to cut off the bearing caps from the top casting, then machine them and the top casting to size before re-attaching the bearing caps ready to bore out the holes for the bearings.

For those of you also building this engine, I have definitely found an error in one of the drawings and this has been confirmed as such by EE.On drawing number 4 - Bearing carrier, the bottom view shows 6 holes on a 19mm radius, but a sectional view at the bottom of the same drawing shows these holes as being on a 20mm radius. The base casting, with which these holes marry up, also shows a 19mm radius. If anybody is aware of any other discrepancies on these drawings, please feel free to post them here so that we all benefit.

[Jasonb]

Ray I think the 19mm radius refers to the single hole which matches the singel hole on  drawing No 3.

The 20mm radius is for the six mounting holes

On drawiong 3 you can see more clearly that the dotted 19mm radius circle is withing the six holes

[RayW]

I see what you mean Jason, but if you look at drawing 1,it just shows a single radius of 19mm for all seven holes. I have checked the drawing with a pair of dividers and all seven holes are definitely drawn on the same radius.This is clearly different from drawing 3 but consistent with drawing 4, It looks, therefore, as if drawing 3 is the odd one out.
As shown earlier, I have made up a drilling jig for all seven holes on the same radius. As far as I can see, the radius is not critical, as long as the holes in both castings match, and the water holes line up in both.

[Myrickman]

Nice job on the crank Ray....bummer about the dims being off. Looks like a speedy recovery was had though.

[Dave Otto]

Yup, I was thinking the same thing Paul; the crank shaft looks real nice!

Dave

[RayW]

Work is progressing steadily with the crankshaft now mounted in its bearings. I made the camshaft out of stainless steel, with the cam lobe being made as a separate item, then silver soldered to the main disc. The drive pin is Araldited in place. The first attempt at silver soldering the lobe proved a bit of a disaster, when I managed to solder the whole thing to the clamp that was holding it in place!! Fortunately, the second attempt was more successful.
As far as I can see from the plans, there does not appear to be any provision for a bearing for the camshaft, with it just running in the aluminium casting, but I plan to use a bronze bearing.

[Roger B]

Coming along well    That's an interesting way of making a cam. Was it easier to make the lobe separately? Couldn't you use whatever technique you used to form the lobe directly on the cam blank?

[RayW]

Hi Roger. As you say, an unconventional way of making a cam, but this was actually how it was shown on the CD supplied with the kit, except that the disc and the shaft were to be made as two separate components, then somehow fixed together.
The cam is simply a flat strip of 1.5mm thick strip with the ends filed to a taper after silver soldering to the disc.I also cleaned up the faces of the cam in the lathe after soldering.
I couldn't see the point of making the disc and shaft separately so turned them as one piece.