Member postings for Ron Laden

Thanks Geoff/Jason and thanks for your help, much appreciated.

I am really chuffed with it I imagined a lot of fiddling and adjusting so it was a surprise when I turned on the air, gave it a flick and off it went..

I would like to build in some counter balance to the steel flywheel if possible but how do you calculate how much or is there an element of guesstimation..?

A video below with some sound, excuse the sound of someone taking their last breaths its the airbrush compressor which is an on demand type. Although it provides a constant air pressure it switches itself on and off constantly.

Edited By Ron Laden on 10/02/2020 17:07:51

Impatient as I am and having not yet received the steel for the flywheel as well as being mad keen to see if the engine would run, I searched the shop for something to fashion a temporary test wheel. The only thing I had was a short piece of 3 inch diameter 6082 so I used that, its not very true but as it turned out it served its purpose.

The good news is the engine ran straight away with no problems and I have made no adjustments to it, as it is in the video is how it ran from the start. I havnt shown it at its top end speed as it would take a walk across the bench with out it been held down. This is all new to me but I was surprised at the bottom end speed which I thought quite slow for a aluminium flywheel, it will be interesting to see if that changes with a steel wheel.

Anyway it goes without saying I am really pleased with it.

p.s Apologies for the poor quality video, the original is much better dont know what happened there. 

Edited By Ron Laden on 10/02/2020 13:33:17

Thanks Jason, it will only be running for display so I think the spring I am using should be ok.

I turned up a temporary plinth/work stand to save it lying around or having to prop it up on the bench.

Thanks Geoff/Jason, up early this morning and I lapped in the faces.

Something that has surprised me is the recommended compression spring, its quite a strong little spring 4.3mm i/d 0.7mm wire with 10 coils in 12.7mm length. Anyway I dont have one to that spec but I have one which matches the diameter and the wire but is more open with 7 coils per 12.7mm, I will give that a go it is adjustable of course.

Ron

The surface finish of the mating faces of the cylinder and column have turned out really good, excellent in fact but is it normal practice to lap them in to each other, I am guessing it is ..?

Thanks Jeff/George, I must admit I am enjoying making it and learning a few things along the way.

Ron

Finished the column this morning, well apart from going around it with the needle files. A couple of changes I have taken the inlet and exhaust straight through to the back of the column, I just thought it neater than on the sides. Also the brass bar I used wasnt big enough to include the column base fixing lugs/brackets as a one piece part but I will machine those in the base plate for the same effect.

A couple of pics, one showing that the parts actually fit together..

Turned the column this morning, it looks a tad different to the drawing mainly because I used a 4mm radius form tool I had ground up for another job and I used that for the shaping.

To the mill next, hope to get it finished in the morning.

Excuse the poor quality picture.

The small parts are ready and the brass bar has arrived for the main column, I have also got a 100mm x 10mm steel round on the way to have a go at making a flywheel.

The cylinder is honed and the piston lapped in, my first time doing that and I really enjoyed it, very satisfying. The piston fit I think is good, its smooth, free and as close a fit as I could get, so here,s hoping it will prove ok when running.

That's neat Jason I can see how it keeps the piston/rod true, if threaded only and fitted dry do the pistons tend to unscrew in running.

Nice work Jason as usual, I noted that the bottom cylinder cover has a recessed spigot to allow for the piston retaining nut. I wondered is the piston threaded and then the nut acting as a lock nut or is the piston rod plain but with a shoulder and the nut pulling the piston onto a shoulder.

Thanks Jeff/Geoff,

It just seemed a bit easier for the same end result and I do tend to enjoy a bit of filing to shape, quite satisfying.

Ron

Crank arm made and fitted, its not perfect but the best I can do by hand with a couple of files. Its reasonably tidy and the hole centres are good so I think it will do.

Thanks Jason

I will give it a try.

Jason, I have found some Pine dowel in the shed would that do for the cylinder honing or does it really need to be hardwood.

Ron

Just out of interest it is quite recent that I got myself some GT inserts, previously I had been using MT inserts and HSS tooling on most of the lathe work. I have to say that I am very impressed with the GT type, not only are they excellent on alu, brass and the like I have found them very good on steel, well on EN1A at least.

The crankshaft I turned this morning from 1/2" EN1A down to 5.0mm and used a GT for all of it, not just the finishing cuts. I guess there must be a limit on the depth of cut but I took some 1.0mm cuts with no problem at all and even at 1.0mm the surface finish was very good.

I dont know how you guys find them but I think they are excellent.

Edited By Ron Laden on 02/02/2020 17:16:24

Hi Bob, I would never have thought of a nebuliser but I needed a new airbrush compressor anyway so I have killed two birds with one stone (hopefully)

The engine looks nice which model is it..?

Ron

Turned up the crankshaft and its bearing this morning, went with a different approach to the drawing. The drawing shows the crankshaft as a plain shaft with the crank arm added (close fit) then pinned, also the same fixing for the flywheel.

I have turned up the shaft with a stepped boss as a one piece to which I will lightly press on the 4mm thick connecting arm plus a dab of retainer. The end result will look the same, I thought it just bit easier then machining up the one piece arm and boss.

Edited By Ron Laden on 02/02/2020 09:29:08

Only had time for two small parts today, the big end and the piston. The piston is 0.004" oversize, hopefully that is enough for adjusting its size ready for lapping in once the cylinder is honed.

Should have some brass bar on Monday so I can make a start on the column.

Jason,

I found the drawing for this little engine on the "MEWS Models to Build" site and this morning I found your build thread of the Monitor Ball Hopper Hit n Miss Engine, I have to say that it is seriously impressive, quite a large lump of an engine and quite involved to. The setting up for machining of some of those awkward castings was impressive in itself let alone all the other parts you had to produce.

Excellent stuff Jason was it a good runner.