Author Topic: Mery Explosive Engine  (Read 14159 times)

Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #90 on: December 18, 2024, 06:36:14 PM »
Thanks Dave, I'll study that explanation this evening after dinner. I've just come in from my workshop having machined the stuffing box. I was particularly careful with this part because good fits are required to ensure the cylinder lines up with the bed of the engine and the gland will need to be gas light without pinching the piston rod.

Here are some pictures of the stuffing box, not finished but almost there...

  IMG_0665 by Andy, on Flickr

IMG_0667 by Andy, on Flickr

IMG_0669 by Andy, on Flickr

IMG_0671 by Andy, on Flickr

IMG_0673 by Andy, on Flickr

Andy

Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #91 on: December 19, 2024, 08:11:02 PM »
Another Mery part machined this afternoon - the bronze gland casting to fit in the stuffing box. I see the studs are arranged in the vertical plane on some models, the horizontal orientation would seem to make the nuts more accessible and adjustment of the gland much easier.
I intend to use Loctite 648 to retain the stuffing box in the end of the cylinder rather than the heat shrink fit as per the drawings.

IMG_0676 by Andy, on Flickr

IMG_0679 by Andy, on Flickr

IMG_0691 by Andy, on Flickr

IMG_0682 by Andy, on Flickr

IMG_0684 by Andy, on Flickr

IMG_0687 by Andy, on Flickr

Dave - I read the description and think I now understand what the mechanism is supposed to do, thanks for your post.

Andy

Offline Dave Otto

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Re: Mery Explosive Engine
« Reply #92 on: December 20, 2024, 01:22:01 AM »
You are welcome Andy, glad to be able to help.
I had to laugh about the shrink fit, Roland loves shrink fits. If you didn't know Roland Morrison ( Morrison & Marvin Engine Works) was really the driving force behind the Mery Model.

Dave

Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #93 on: December 23, 2024, 09:36:51 PM »
A little more progress this afternoon, I machined the piston and was able to part off five rings from the stub of the piston casting.

The piston is 3/4" long with three 1/16" piston rings. I used a 1/16" grooving tool for the piston ring grooves.

IMG_0699 by Andy, on Flickr

Bored out the stub to form piston rings

IMG_0703 by Andy, on Flickr

Parting off piston rings

IMG_0705 by Andy, on Flickr

IMG_0706 by Andy, on Flickr

Parted off five rings, I'll split and heat treat them tomorrow.

IMG_0709 by Andy, on Flickr

The centre of the piston is threaded 1/4" x 32 tpi and screwed on to the piston rod. It's a good sliding fit in the cylinder at the moment.

IMG_0711 by Andy, on Flickr

IMG_0713 by Andy, on Flickr

Merry Christmas

Andy

Offline Alyn Foundry

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Re: Mery Explosive Engine
« Reply #94 on: December 24, 2024, 12:51:24 PM »
Thanks Andy.

And a very merry Christmas to you too.

 :cheers:  Graham.

Offline propforward

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Re: Mery Explosive Engine
« Reply #95 on: December 24, 2024, 01:30:29 PM »
Excellent work Andy - continuing to follow with great interest.
Stuart - "He Meant Well"

https://www.youtube.com/@StuartsShed

Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #96 on: December 24, 2024, 05:16:12 PM »
Cheers Stuart, Graham and everybody else on MEM  :DrinkPint:

I split and heat treated the piston rings this afternoon, reckon that's it for a few days.

Andy




Offline Michael S.

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Re: Mery Explosive Engine
« Reply #97 on: December 24, 2024, 05:20:22 PM »
What a beautiful engine!
Merry Christmas Andy.

Michael  :cheers:

Offline pirmin

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Re: Mery Explosive Engine
« Reply #98 on: December 26, 2024, 04:48:21 AM »
Cheers Stuart, Graham and everybody else on MEM  :DrinkPint:

I split and heat treated the piston rings this afternoon, reckon that's it for a few days.

Andy


Hehe, nice work, i did the same today, i made a piston and the rings.... :cheers:

Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #99 on: December 26, 2024, 10:32:51 AM »
Hello Pirmin, I am following your engine build, well done with fitting your piston rings.

Andy

Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #100 on: January 26, 2025, 06:20:49 PM »
Not much time for model engineering so far this year but I have fabricated the crankshaft using 16 x 12.5mm steel for the webs and 1/2" silver steel for the crankpin and shafts. I followed the usual method and the crankshaft seems to be ok so far....

Crankshaft webs by Andy, on Flickr

Drilled and reamed on the faceplate.
Crankshaft webs by Andy, on Flickr

Ready for silver solder. HT5 flux applied to the joints then correction fluid used as a barrier to prevent the solder adhering to the crankpin and journals.
Crankshaft prepared for silver solder by Andy, on Flickr

Cooling down.
Crankshaft red hot after silver solder applied. by Andy, on Flickr

Test fit in the main bearings.
Test fit in the main bearings. by Andy, on Flickr

Shaft stayed straight after removing the section between the webs.
Test fit in the main bearings. by Andy, on Flickr

So far so good
Crankshaft looks OK by Andy, on Flickr

Next job is to mill keyways in the shafts then clean and polish.

Andy

Offline crueby

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Re: Mery Explosive Engine
« Reply #101 on: January 26, 2025, 07:34:19 PM »
Great  job on the crankshaft, you make it look easy!


Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #102 on: February 03, 2025, 06:21:31 PM »
Thanks Crueby.

After milling 1/8" keyways in the crankshaft my next job was the connecting rod.

The connecting rod has a bronze big end bearing mounted on the foot of the rod and the other end is connected to the crosshead just like a steam engine. The only material to hand was 1.3/8" diameter mild steel so a lot of swarf was going to be made. I assumed the steel was EN1A PB that I bought years ago but it was hard work. I achieved the best results using a button tool taking 0.030" cuts at 1,000 rpm, the finish was excellent but the swarf came off in continuous long coils sharper than razor wire.

IMG_0863 by Andy, on Flickr

IMG_0860 by Andy, on Flickr

IMG_0860 by Andy, on Flickr

The connecting rod is supposed to have a taper of 0.008" per foot. That entailed a lot of messing about trying to get the taper turning attachment on my lathe to work properly but I got there eventually. The taper was more consistent machining towards the tailstock, I suppose there must be excessive backlash somewhere.

IMG_0862 by Andy, on Flickr

On to the milling machine to form the ends of the connecting rod.

IMG_0869 by Andy, on Flickr

IMG_0872 by Andy, on Flickr

IMG_0876 by Andy, on Flickr

Using a square collet block.

IMG_0880 by Andy, on Flickr

Nearly there.

IMG_0883 by Andy, on Flickr

Little end bored and reamed to 3/8" and the end rounded.

IMG_0884 by Andy, on Flickr

 IMG_0885 by Andy, on Flickr

Andy

Offline Michael S.

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Re: Mery Explosive Engine
« Reply #103 on: February 03, 2025, 07:01:10 PM »
Hello Andy, the connecting rod looks very good. A nice smooth surface.

Michael

Offline Chipmaster

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Re: Mery Explosive Engine
« Reply #104 on: February 05, 2025, 08:14:03 PM »
 :ThumbsUp: Michael

Two pieces of leaded bronze parted off to be the split line of the bearing then soldered together.

 IMG_0889 by Andy, on Flickr

IMG_0893 by Andy, on Flickr

Bored and reamed out to 1/2" to fit the crankpin.

IMG_0897 by Andy, on Flickr

Then machined to fit between the crank webs.

IMG_0904 by Andy, on Flickr

Mounted on a mandrel and machined to match the width of the foot of the connecting rod.

IMG_0907 by Andy, on Flickr

IMG_0910 by Andy, on Flickr

IMG_0911 by Andy, on Flickr

I used silver solder to hold the two halves of the bearing together and was surprised when it started to come apart as I used a 1/2" hand reamer so I added the two 5BA bolts at an earlier stage than planned. The bearing seems to have survived but had some scratches in the bore so it will benefit from a dose of Timesaver lapping compound to improve the reamed surface.

Will be attached to the connecting rod next.

IMG_0913 by Andy, on Flickr
Andy
 
« Last Edit: February 05, 2025, 08:53:00 PM by Chipmaster »

 

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