Mery Explosive Engine

[Dave Otto]

Nice work, innovative setups, and great progress!!

Dave

[Chipmaster]

In reply No 5 posted 11 September Jason asked "It would be interesting to know what method they used to cut it,"

On my travels this morning I called in to Redditch Gears to ask, they showed me the machine they used, it was a Drummond Maxicut 2A.

The Lathes.co.uk website describes the Maxicut machines and contains several pictures of the machines.

https://www.lathes.co.uk/drummond-maxicut-gear-shapers/

Andy

[crueby]

Those machines are amazing!  Gleason, another maker of gear cutting machines, has a big plant here in Rochester, someday I hope to wrangle a tour there.

[Chipmaster]

Hello Crueby, yes they are fascinating. There were many machines at work this morning machining gears of all sorts and sizes all producing very high finishes. The cutting action was usually obscured by the flood of cutting oil.
Andy

[Chipmaster]

The flywheel is just the right size for my faceplate.

Flywheel casting by Andy, on Flickr


Flywheel casting by Andy, on Flickr

Flywheel casting by Andy, on Flickr

Flywheel casting machined by Andy, on Flickr

Flywheel casting machined by Andy, on Flickr

After broaching  keyways in the flywheel and spur gear I cave it a spin.

Flywheel and spur gear keyed on to dummy crankshaft. by Andy, on Flickr

Andy

 

[Jo]

Always a good bit to make as it give you something to twirl and watch go round and round   

Jo

[crueby]

Great looking flywheel,  excellent proportions.

[Jasonb]

Starting to look like an engine now and thanks for the gear cutting details.

Been doing a bit of flywheel twirling myself today.

[john mills]

interesting to see the gear cutter i have used a similar machine made by TOS  it would have been similar size
john

[Roger B]

Looking good     

[Chipmaster]

Now for the cylinder jacket which was bored out to 1.75" diameter.

My four jaw chuck couldn't be expected to hold the casting without it moving due to the length of the casting and the interrupted cuts. I machined the flange on the end of the casting to be supported with a fixed steady. I ran the lathe at a slow speed.

  Cylinder casting held in a four jaw chuck. by Andy, on Flickr

 Cylinder casting supported by a fixed steady by Andy, on Flickr

 Cylinder casting supported by a fixed steady by Andy, on Flickr

The cylinder liner casting was held in an Edwards Four Jaw Self Centring Chuck which has a very strong grip.

Machining the outside of the cylinder liner by Andy, on Flickr

The drawings specify the liner should be a shrink fit. However, I preferred to use Loctite 638 which has been completely reliable retaining the liners on other engines I have built. My wife wouldn't let me use our oven anyway. I thought the passages for the water inlet and outlet looked rather restricted so I used a Dremel with a grinding point to improve the flow. Some of the completed Mery engines on YouTube use pumps to improve the coolant flow, I would like to avoid having to pump the coolant if possible.

I allowed two days for the loctite to cure then it was back on the lathe to bore the liner out to 1.5"

Boring out the cylinder liner to 1.5" diameter by Andy, on Flickr

It took a long time to produce a parallel bore because the boring bar was deflected, perhaps I should have taken the time to set the casting up for between centres boring.

The cylinder was machined to length 5.532" facing the ends by mounting it on a aluminium  snug / tight fitting mandrel that was machined in the collet chuck  to ensure the faces are at right angles to the bore.

Facing the ends of the cylinder by mounting it on a snug that was machined in the collet chuck  to ensure the cases are at right angles to the bore. by Andy, on Flickr

I used a piece of the 1.5” aluminium snug to temporarily attach the cylinder, it’s a long engine, about 22 inches long!

IMG_0236 by Andy, on Flickr

IMG_0231 by Andy, on Flickr

IMG_0228 by Andy, on Flickr

IMG_0237 by Andy, on Flickr

Andy



 

[Chipswitheverything]

Very nice work and set-ups shown in the photo sequence.  A cylinder of that length and bore is quite a demanding machining prospect, the larger lathe probably an asset in handling it rather than using a Myford sized machine.  Flywheel looks very good ....   Dave

[Chipmaster]

Hello Dave, yes the cylinder was certainly demanding, it is just too long for my longest indexable boring bar as used for my Stuart Major cylinder which was only 1/2" shorter than the Mery cylinder.

Boring my Stuart Major cylinder (5.125" long) 8 years ago.

  S Major 0316 by Andy, on Flickr

I considered buying a longer indexable boring bar say 10"+ but at that length the diameter is usually too large for my toolholder, they're also expensive.
The blue painted carbide tipped brazed boring bar that I had to use is probably best for rough turning but a few minutes work with a three stone hone produced a satisfactory finish.

Andy

[Chipswitheverything]

Thanks Andy : I haven't got any photo of boring my Major cylinder, so long ago that it predated waving any sort of digital camera at it ...  I seem to remember setting it up for between centres machining on the Myford boring table.  Made up a fairly hefty Geo. H. Thomas adjustable boring bar, which has been useful for the Quorn and at other times. 
  As it looks like a week of mostly rain ahead of us in Southern England, and not much good for other than indoor activities, I will have a go at getting my Major Beam finally assembled, at immensely long last!.  Been doing a few of the last drips and drabs of left over jobs, pipe bending and brazing flanges, making the curved crank well trough.  'Spect that I'll find a few more overlooked oddments to need to attend to while building, a few things that need measuring off from the components in situ, or the odd stud and nut that has gone AWOL.   Dave

[Chipmaster]

Go for it Dave I'm looking forward to seeing your Stuart Major assembled and running.

Andy