As it's been a bit quiet in this part of the forum I thought I would post some of the parts that I used the CNC to make for this engine that I started on the 2nd of April and got to the stage of a test run today. I have had the main parts 3D modelled for a few years but never got round to completing the design but Lockdown found me wanting a new project so this is the result, get your ear plugs ready Roger
Completed model in Alibre inspired by and roughly based a Filer and Stowell rocking valve engine.
First parts were the two 16mm thick pieces of aluminium that form the bearing supports, rough cut on the vertical bandsaw then contour cut on the CNC
More details of cutter, feeds etc under the Youtube description, you may want to skip some of this.
These were followed by the bearing caps
I often use a bought in flywheel casting for my own design engines but this time decided to cut from solid so a piece of 130mm dia EN3 got roughed out on the manual machines then finish shaped on the CNC.
Again details in description and definately worth skipping a few bits. ramp was probably not the ideal finishing strategy but I learnt a lot for the next one
Also did the plates that go at the bottom of the main "castings" from 3mm steel
The oval piston rod gland and boss, screwed together and machined as one
The recess either side of the crank disc were also ideal jobs for the CNC
Got the other critical small bits finished today and tacked it together with a few odd screws, no piston ring, gland packing or gaskets and the valve links only have screws instead of fitted pins but it ran as soon as I put air to it. Bit of a tidy up and some finishing touches needed now.
I'm not usually that interested in stationary engines although I appreciate what goes into them like any model but that is lovely and a bit different and I love the models you produce. Please post more about them as you seem to produce quite a few!
Trying to Finish 5" 9f Producing Scale fittings using 3D wax printing and lost wax casting - www.crofittings.co.uk/ Renovating house stopping all of the above!
Thank's for the comment guys, the engine has had the detail bits added and a coat of paint. If you can bear to watch to the end where it is running slowly I think the valve rod needs a tweak as the instroke is stronger than the outward and I also need to get a longer belt for teh governor as the standard mamod one is too short and putting a lot of strain on teh overhanging pulley which is just on a 1/16" shaft.