Elmers Engine 2x#33

[timo_gross]

For some time I am thinking if it is a "good idea" to hook up two of those Elmers Mill Engine #33 on the same crank shaft?


Something similar to this.

Questions:

Do or do not? haha

Is it O.K. to put the valve chests into the middle facing each other?

I wonder if I can make the cylinders out of cast iron? I still want to make the base from Aluminium is that a weird combination?

Greetings Timo

 

[Jasonb]

The only thing to think about is getting the chest covers off to set the valves which will need a spanner rather than nut spinner.

Cylinders would be quite easy from a block of CI, bore, face and turn one flange. Reverse in chuck and turn the other flange then mill away the mid section to shape.

It will be OK mixing materials

 

[timo_gross]

It will be OK mixing materials

Hello thank you for the reply, I think I will give the cast iron bar a try then.
And keep the hint for the covers in mind.

 

[johnmcc69]

Any particular reason why you would want the valve chests inward?

John

 

[Jasonb]

Makes for a simple crankshaft where the single crank webs just fit either end of the shaft, if you have them facing out you need two webs to each crank and a shaft out either side. If you have them ontop which is another option you then need a more complex linkage from eccentrics to valve rods

 

[johnmcc69]

But what about the valve eccentrics? How do those work when the valve gear is inside the crank throws?

John

 

[GreenTwin]

I think "spanner" is British-speak for a wrench?

I don't know what a spinner is, but my guess is that means socket wrench?

I have seen lots of British words that I have had to think about, such as nappie, flat, bin, lorry, etc. (diaper, apartment, garbage can, truck).

.

 

[GreenTwin]

Just put the eccentrics inboard of the bearings, with the crank disks being outboard of the bearings.

.

 

[johnmcc69]

Sorry for that question (Eccentrics) . "Duh". Must be Monday.

I hope the rest of the week gets better...

John

 

[Richard Hed]

Makes for a simple crankshaft where the single crank webs just fit either end of the shaft, if you have them facing out you need two webs to each crank and a shaft out either side. If you have them ontop which is another option you then need a more complex linkage from eccentrics to valve rods

Well, I would consider putting them on the outside, not inside

 

[Richard Hed]

I think "spanner" is British-speak for a wrench?

I don't know what a spinner is, but my guess is that means socket wrench?

I have seen lots of British words that I have had to think about, such as nappie, flat, bin, lorry, etc. (diaper, apartment, garbage can, truck).

.

Lift, and I thot the Brits knew English!

 

[timo_gross]

Haha I thought spanner and wrench are basically same thing? I am not native writer, so my English can be very off at any time.

Yes the valve chests inside make for a easier crankshaft, with the flywheel in the middle.
The idea is that I basically mirror one and put them side by side.
Put the valves on top? ..... That would be 2x#41....
Keep it in mind.

Greetings Timo

 

[Jasonb]

On a lot of simple models the eccentrics are slid onto the crankshaft before the crank arms are finally fixed.

More detailed model would have the eccentric split and suitable clamping arrangement so the two halve scan be fitted to the shaft, much like you see on the middle eccentric of a triple expansion engine

This image shows why putting them on the outside is a lot more work, you need to extend the crankshaft so that there is something to fit the eccentric to, that then really needs supporting with additional bearing and pedestal and you then end up with a four bearing setup which is a lot harder to get all 4 lined up. The insid eoption is a simple shaft with a single throw at each end

This is a nut spinner, lot easier to use that a spanner (wrench) Same would apply for a hex ball driver for those that use socket head screws. But as you only really need to be setting the valve position once (hopefully) it's not such a big issue.

https://ghw-modellbau.de/Steckschluessel-mit-Laengsgriff-CrVhttps://www.modelfixings.co.uk/tools.htm#Ball Drivers metric
There are some popular models out there that have the inward facing valve chests such as the Double Tangye which has the same layout as the full size which was more compact that an similar engine with the chests sticking out the side

 

[awake]

Just to round out the confusion ... I thought all of the eccentrics were members of this forum!

 

[timo_gross]

Just to round out the confusion ... I thought all of the eccentrics were members of this forum!

Yes, apparently they are made of all sorts of materials. Organic, Brass, Aluminium, some even may have some titanium parts inside. Or Ceramics for that matter.

I decided to start making the first parts. If I really cannot get it assembled no one can say that I have not been warned.
Plan B would be to relocate the valve chest to the top version (#41) It shares enough parts to be able to it without starting over again.

 

[Jasonb]

I don't think you will have a problem getting it assembled, it is just a bit more fiddly with them facing inwards. You could probably actually set them before final mounting of each engine.

You could make setting up easier if you have some additional countersunk or counterbored holes to screw the chest to teh cylinder and then only teh cover needs to come off for setting the valve

 

[timo_gross]

I don't think you will have a problem getting it assembled, it is just a bit more fiddly with them facing inwards. You could probably actually set them before final mounting of each engine.

You could make setting up easier if you have some additional countersunk or counterbored holes to screw the chest to teh cylinder and then only teh cover needs to come off for setting the valve

Yes that makes sense.
Have to see if it is possible, because the cover will be is quite small. 22x15 mm or (0.9x0.6"), not much material to hide a screw inside, but maybe a pin does it too.

I am thinking of 95 mm flywheel diameter.

Greetings Timo

 

[Richard Hed]

Yes, apparently they are made of all sorts of materials. Organic, Brass, Aluminium, some even may have some titanium parts inside. Or Ceramics for that matter.

I decided to start making the first parts. If I really cannot get it assembled no one can say that I have not been warned.
Plan B would be to relocate the valve chest to the top version (#41) It shares enough parts to be able to it without starting over again.

It's good that you decide for yourself after seeing all the advice. As for myself, I disagree with Jason. It is true that one needs to extend the crank shaft, but not necessarily have extra bearings or pedestals.

 

[timo_gross]

It's good that you decide for yourself after seeing all the advice. As for myself, I disagree with Jason. It is true that one needs to extend the crank shaft, but not necessarily have extra bearings or pedestals.

A lot of the advice is valuable for near future. Maybe I have to read through it once over.
The "free floating" eccentric without the extra bearing would probably look a little awkward. But now as you mention it. Still some extra parts and more complicated to align everything properly.

67 parts to make and not one yet finished..... so far only talk (type).

Greetings Timo

 

[Richard Hed]

A lot of the advice is valuable for near future. Maybe I have to read through it once over.
The "free floating" eccentric without the extra bearing would probably look a little awkward. But now as you mention it. Still some extra parts and more complicated to align everything properly.
View attachment 145465
67 parts to make and not one yet finished..... so far only talk (type).

Greetings Timo

But that's good to plan ahead for exactly what you want. When I was in college (last week) the professors would always like what I proposed as a project, however, the first thing they would say is "Draw it up and let me see it". Of course to a young whipper snapper that is throwing cold water on two dogs itting. But now in my old age (12 years old) I see that they are right. MY projects were never really thot thru properly and doing a drawing clarified what I had not even considered. So you seem to be thimpfking carefully about your intentions. Good

My son is going thru that stage but he only makes a poor sketch and it barely gets him to see his mistakes or omissions. Him and I want to make a couple revolvers or some other kind of hand guns but we have no drawings. One of the places I visit somethimes is John-Toms. I thimpfk they have pistol and guns in general plans for sale. Does anyone know of other gun plans for sale?