The Workshop Progress thread 2018

As Santa failed to get the CNC mill with 4th axis down the chimney I had to resort to manual knob twiddling to make this. It is the cylinder for my current project which takes a lot of its features from an engine with spiral cooling fins.

I used the 72 turn rotary table from ARC and did it in half turn steps so the z-axis and rotary table had to be adjusted and the quill plunged 144 times per rev. I used a 7.2mm pitch which worked out nicely at 0.05mm per half turn of the handle. Did most with a 5.5mm 3-flute cutter and then swapped to a 3mm to feather out the ends.

Excellent Jason, but how long did that take..?

About 3hrs milling spread over 5-6hrs as I needed a break after each rev and it also let the motor cool.

Can we all start a whip round to buy Jason a tripod for his camera?

Edited By David Standing 1 on 28/12/2018 21:05:29

I thought it would have taken much longer than 3 hours. Thats an impressive piece of machining and just goes to show what can be achieved on a manual machine, providing you know what you are doing of course..

Nah. We'll just get him the plans for the George Thomas Universal Steadycam Attachment.

What use is a tripod when you want to move the camera about to show different views of the engine? The actual square on shots are quite steady. Mark is more on the right track with his GT giro balanced gimble but even then would still be moving the camera to various positions.

That would have taken me 5-6 days and then I would have b*****ed it up near the end!

Russell

Jason, is this an engine of your own design or is it still under wraps until its finished. I,m intrigued by the spiral cooling fins, never seen those before but they do look good.

Ron

Phones and ipads etc are inherently difficult to hold steady IMHO

If you are using a camera monopods are a good idea as is also a length of cord with a fitting for the tripod bush on the camera on one end and loop for your toes at the other. Tension the string and the camera is suddenly a lot steadier. (Works best when the camera has a central tripod bush)

Ron, it is loosly based on a 1/15th HP Forest engine of 1883. I hope it will work as a flame licker though the original was a non compression external flame ignition design which is hard to model and get running without some fancy cocktail of gasses. It will have the spiral cooling fins and the "Evans Beam" conrod arrangement of the original. I'm doing it with my usual 24mm bore so scale is about 1:2.5

Cylinder looks a bit more like a casting now it has been fettled

Interesting Jason, is a flame licker the type of engine which has an external burner next to the cylinder.? Also is that a balloon on the forest engine, it looks like one, something to do with the gas maybe..?

Flame licker has an external flame that is drawn into the cylinder as the piston moves one way then that hot air which was drawn in cools and sucks the piston down by vacuum. Like my Chuky if you have seen that.

The Forest first draws in gas/air and then a small flame is also drawn in which ignites the gas driving the piston to the top of it's stroke and then the spent gas is exhausted on the return stroke.

The balloon is known as a gas bag, you regulate the supply to a slow steady flow which inflates the bag and then it can rapidly draw in from the bag at low pressure, bag refills during the rest of the cycle.

This is a 1:1 replica of the Forest in action on a Hydrogen based gas cocktail.

Jason, also watched the video of your Chuky engine running, great stuff, I love the sound. Look forward to seeing your new build up and running.

Ron.

My last bit of progress for this year. More rotary table work on the bracket that supports the crankshaft and takes the exhaust valve housing.

Soldered on a couple of lumps of steel and pokes a pair of holes in for the bearings

Seems to fit OK, just need to shape the bearing caps and then soften all the hard edges to make it look like a casting