Engines > Your Own Design

Reinventing the Real.

(1/10) > >>

Jasonb:
While making the Stuart Victoria last year I started to feel like I would also like to make the Real to go with it. So I bought Andrew Smith's book (cheapest source of drawings) on building the Real and started to look a pictures of them on the net, the more I looked the more I saw that I did not like and that included what Stuarts are asking for the kit. So over a few winter evenings I developed a different version that has gone by the working tile "Unreal" which addresses some of these issues and also more closely follows the etching from Andrew's book that was his inspiration.



Although I could have made the flywheel and cylinder from scratch I decided to use just these two Stuart castings as I felt that others who may want to follow suit would find these the most difficult parts to make from scratch. I also went for a metric design based on nominal sizes rather than direct conversion of the old imperial sizes again with many beginners now of an age where they were taught metric at school that make sense and if using handwheels on modern metric machine sit is easier to keep track of whole metric numbers rather than working to several significant figure after the decimal point. This results in a model with 25mm bore and 50mm stroke

I'll go into more detail during the build about the various modifications but a summary is as follows

Base - This is a very expensive casting at 45 for what is little more than a rectangle with tapered sides and rounded corners So something with a bit more shape and detail
Columns - Again something with more shape and detail than the plain tapered ones
Entablature - This is shaped the wrong way for any form of classic architecture being larger at the bottom than the top all for the sake of easy removal from the sand so that needs to be corrected and some additional detail added at the same time
Pulley - change for one closer to the one shown in Andrew's book not the standard Stuart one used on all their 2 x 1 models
Flywheel - remove the "lumps" they now cast on the rim, add some counterbalance weight and fit with a gib head key
Valve/eccentric - modify layout to do away with the dog legged valve rod and make an eccentric correctly shaped for vertical use
Cylinder - move exhaust position as it gets a bit tight between column and exhaust position
Crosshead and guides - change to rod guides which was another feature of the engraving in Andrews Book.
Conrod - change from the tuning fork design to one similar to the other 2 x 1 Stuarts and Andrew's etchings

On the cost front this model work out at about 200 which is half of what Stuarts are currently asking. This is based on buying most materials by the 300mm length so you will have some over for the next engine. Larger diameters by the 25mm length where available. The cost also includes enough for fixings etc as well as the price of the two castings.

A few more bits of tooling and cutters may be needed but those will last a long time and if used over several more models will not amount to much. I did make use of my CNC for some of the parts but just about all could be done with manual machines and only one part would need a bit more of a redesign to make it a bit easier to cut from solid.

Next time I'll start on the construction of the base. And don't worry as unlike the Wall engine this one is finished and runs very well so there will be a happy ending to the build.

crueby:
Nice proportions on that! Looking forward to seeing this one develop...

Jo:
The Real engine is rather nice  :embarassed:



Jo

samc88:
Thus sounds great, I shall be keenly following along

Sent from my SM-A127F using Tapatalk

10KPete:
That's quite the impressive engine, Jo! What was it powering?

Navigation

[0] Message Index

[#] Next page

Go to full version