Author Topic: Myrick Eclipse one-third scale model part two  (Read 8242 times)

Offline Myrickman

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Myrick Eclipse one-third scale model part two
« on: April 16, 2017, 01:36:41 PM »
Part one was to construct the model shown and is described in a build log on another site. These were common pumper engines in the  oil and gas fields. About two years ago I happened onto another full sized, early engine like this one except with a ported cylinder. I took the model to several shows and got several requests for castings. This past winter, I had the patterns cast for those requests and also made with a modified ported cylinderfor myself. Since I had built one already, I could now get the port location right. Number one was built with no plans, just a cutaway drawing of the full sized engine.
The model has a 2" bore and 2-1/4" stroke. Fuel is propane and ignition is via hot tube. The hot tube is a piece of  1/4 stainless tubing about 2-1/2" long. She's a hefty girl weighing in at about 65 pounds finished. Governing is hit and miss via a lollipop weight pivoting about the flywheel. I'll be starting this one in the next few weeks as I have to add some sketches for the parts not documented in the original build.
« Last Edit: April 16, 2017, 01:40:51 PM by Myrickman »

Offline Admiral_dk

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Re: Myrick Eclipse one-third scale model part two
« Reply #1 on: April 16, 2017, 08:32:30 PM »
Very nice - but not quite a model in my eyes, since she is big enough to do real work  ;)

.... then again, where do you divide sizes ...?

Looking forward to the build  :ThumbsUp:

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #2 on: November 04, 2017, 07:59:30 PM »
Getting back to this build after a busy summer. First task was to square up the cylinder and turn the base for boring in the mill. Here it is in the lathe. The dimensions are shown as an aid to help the half dozen others with kits under construction.  I made a set of sketches for the first one I built and these add details to those sketches.  The cylinder goes in a steel ring which is clamped to the mill for boring. This ring also allows me to center the bore in the casting relative to where the core was. The ring locates on the 2.25" step.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #3 on: November 04, 2017, 08:05:07 PM »
Starting on the arch which supports the cylinder. Four 1/4-20 SHCS hold the cylinder to the base and go underneath. Here the top hole is bored  to receive the cylinder and then flipped over to mill the pockets for the screws.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #4 on: November 11, 2017, 08:32:34 PM »
One of my friends requested more detail on the intake chest. Here it is being machined out of the casting. This engine had a series of small holes in the intake valve seat to simultaneously admit air and natural gas in the oil patch. On the model, two 0.042" holes perform this function. Excuse the dimension cards but I find it an easy way to record my work for later use by others since I do not have formal plans.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #5 on: December 13, 2017, 11:45:43 PM »
Been off this build for a while and wanted to post some progress. Finished the piston and rod. Piston was straightforward. Indicate off the bottom end ID to ensure a uniform wall thickness in the four jaw. Once this surface is cleaned up, flip piston around, knock in a center and machine the OD. Rings are 1/8" wide so roughed out the grooves with a 0.093 parting tool. I made a nice holder for some teeny carbide inserts to finish to 0.001-0.002 side clearance. Rod is silicon bronze and it'll  receive Babbitt in the lower end. The wrist pin is stationary being retained by two 10-32 set screws. This one is going much smoother as I have an earlier set of sketches and am adding refinements.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #6 on: December 14, 2017, 12:00:18 AM »
I'm off on vacation until Christmas so I'm able to plow through some of the big parts of the build. Here I'm putting in the holes to mount the cylinder to the arch which bolts to the base. On the full sized engine, the arch and cylinder are one piece. Here they're attached together with four small SHC screws on the arch underside. I kept measuring and remeasuring everything so the center of the arch is concentric with the bore and ultimately, the base and crank. My DRO readout was acting wonky and needed to warm up for an hour to keep from skipping. Since I just bought it from DRO Pros just three months ago, they graciously and quickly are sending me a new one. As long as crank slow and double check with counting crank revs, it seems to be working.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #7 on: December 14, 2017, 12:08:50 AM »
After carefully referencing my xy datum marks on the base, I temporarily attached the caps to the base and machined the spacing between them to locate the crank. Tomorrow I'll flip the base 90 degrees and drill the caps for the Babbitt to be poured in. The nice thing is I have the jig to pour the mains to size with a plastic simulated piston to ensure the mains ar perpendicular to the bore. A test fit up of the base, arch and cylinder showed me they are all concentric to the bore....whew.

Offline b.lindsey

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Re: Myrick Eclipse one-third scale model part two
« Reply #8 on: December 14, 2017, 12:44:47 AM »
I an envious of the holiday shop time, but you are sure putting it to good use. Great update!

Bill

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #9 on: December 14, 2017, 08:16:57 PM »
Here Are the bearing caps being bored to 1". The crank is 3/4" so there will be 1/8" of Babbitt on the mains. Had my angle plate pre drilled from the last one I built so setup was a breeze. Lower cap center was spot on the center when it punched through the top with a pilot drill.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #10 on: December 14, 2017, 08:22:01 PM »
The fan side of the arch which supports the cylinder gets a cutout to access the rod. Since I didn't have a 3.8" hole saw, I cut the offending piece out on the rotary table using an end mill. With the rotary table centered in I took the opportunity to also cut the cam on the cam gear.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #11 on: December 14, 2017, 08:32:32 PM »
The cam is cut on the side of a standard 16DP gear with 40 teeth. On the original, full-sized engine, the cam is a simple tangential affair with no additional radii. On the rotary table with a sharp 3/4" end mill, I was able to cut it in one pass albeit going slowly. The shoe which rides the cam is rather long so this should help it open more smoothly as opposed to it being a true, what is it, constant velocity or something like that cam. Also, this is a ported engine so there is very little exhaust load on the valve. Having the wax mockup helped in turning the rotary in the correct direction. My work with the rotate table is done so it is unbolted and hefted back into the cabinet. At close to 90 lbs, my back was thanking me for only making one trip.

Offline b.lindsey

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Re: Myrick Eclipse one-third scale model part two
« Reply #12 on: December 14, 2017, 10:16:14 PM »
More nice work and the cam came out especially nice!!

Bill

Offline yogi

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Re: Myrick Eclipse one-third scale model part two
« Reply #13 on: December 14, 2017, 11:16:35 PM »
Coming along nicely!!!  :ThumbsUp:  :ThumbsUp:  :ThumbsUp:
Looking forward to see more...

Offline wgrenning

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Re: Myrick Eclipse one-third scale model part two
« Reply #14 on: December 15, 2017, 01:10:38 PM »
Great Progress!  It wont be long now
Builder of historical models / Restorer of engines

Offline fidlstyks

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Re: Myrick Eclipse one-third scale model part two
« Reply #15 on: December 15, 2017, 01:25:53 PM »
Than you for sharing. I always enjoy some one else's genius and creativity.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #16 on: December 28, 2017, 01:16:15 AM »
Continuing work on the cylinder head. The  head is mounted to an aluminum block first gasket surface down to spot the head bolt bosses and the spot where the intake goes.  The head bolt holes are also drilled. The head is flipped over and the gasket surface faced flat. Head is then flipped and spot drill/tapped to the plate. The main bore for the intake and exhaust chest is reamed to 5/8" and a 90 degree countersink forms the exhaust valve seat. Head is then tipped up on a 55 degree angle to drill/ mill out the passage between the intake/exhaust chest and the combustion chamber. Since this my second rodeo, the passage cutting went way quicker...for that matter the whole head. Still have to counterbore the underside of the head for the exhaust valve guide and drill/tap for the exhaust. Since this is a ported engine, the port takes most of the hot gas load and the exhaust valve merely seals off the combustion chamber for the intake stroke. Did I mention, this is also a hit and miss engine?

Offline Dave Otto

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Re: Myrick Eclipse one-third scale model part two
« Reply #17 on: December 29, 2017, 12:48:33 AM »
Hi Paul

Great progress on the new engine, I have been following along since the beginning but had forgot to post a comment on your work.


Dave

Offline Jo

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Re: Myrick Eclipse one-third scale model part two
« Reply #18 on: December 29, 2017, 09:20:10 AM »
Nice castings and proress :)

Did I mention, this is also a hit and miss engine?

Don't say that too loud around JasonB he likes making Hit and Miss engines especially out of castings  ;)

Jo
Enjoyment is more important than achievement.

Offline Jasonb

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Re: Myrick Eclipse one-third scale model part two
« Reply #19 on: December 29, 2017, 10:10:59 AM »
Flywheels are too big on this one for me to be able to machine :(

Offline Jo

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Re: Myrick Eclipse one-third scale model part two
« Reply #20 on: December 29, 2017, 11:35:43 AM »
Flywheels are too big on this one for me to be able to machine :(

 :ShakeHead: Feeble excuse. It will be good practise for when you do the winding drum for the Superba  :naughty:

Jo
Enjoyment is more important than achievement.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #21 on: December 29, 2017, 12:47:42 PM »
Thanks all for the encouraging comments. I'll be on the flywheels soon and I must say they tax the size capability of my Boxford 280. I purchased the lathe at an auction of a school shops contents being sold off. There were three of them at the auction and sadly, one of them went to a guy who left it in an unheated shed where it rusted badly.
I'm partial to the larger sic models as they can be run slowly and can be made to work on a hot tube.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #22 on: December 29, 2017, 01:04:25 PM »
Finishing the head up here. The casting is mounted to the aluminum chucking block and the combustion chamber is finished machined on the rotary table. I was pleased with the passage between the valve chest and combustion chamber. The exhaust stub is machined also on the rotary table by flipping the whole affair vertically. This setup maxed out the height capability of the Index 747 mill. Had to use a collet and mini chuck to get the pilot hole started. Luckily the drill size for a 1/4 NPT is 7/16...so a collet worked here also to get it to fit. All there is to go is two 10-32 tapped holes for the exhaust valve guide. I'll be working on the guide later today.

Offline Jasonb

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Re: Myrick Eclipse one-third scale model part two
« Reply #23 on: December 29, 2017, 01:20:16 PM »
I thought the flywheels were about 12" if you can fit them on your Boxford 280 they may fit my Warco 280

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #24 on: December 30, 2017, 04:55:10 PM »
Jason, flywheels are about 10.5" finished...made of heavium aka cast iron with thick cross sections. Paul

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #25 on: December 31, 2017, 09:13:38 PM »
Some last of the vacation progress on the build.... With the head completed, next step is to align it with the engine frame to drill the mating holes in the cylinder. Here a piece of 5/8 drill rod orients the center of the valve chest with the main bearing as the thru hole in the head is also reamed 5/8. The head is stuck to the cylinder with double sided tape in the correct position and  a transfer punch is used to spot the female threaded hole locations.
The exhaust valve guide is then machined from the casting. The large round end is turned to fit into the bottom of the valve chest on the head. From there, the turned end is held in a 5C collet in the lathe and the sides of the guide are cleaned up until parallel. The center cutout is made on the mill with the top end filed square for the exhaust valve spring. The valve is a piece of cast iron round stock silver soldered onto 3/16 drill rod.  Happy new year...all the best in 2018. Paul

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #26 on: March 13, 2018, 10:39:36 PM »
Was away from this in early Feb. The fuel mixer gets a thimble cap to cover the intake valve spring so here is the copy based on the factory blueprint. It is about 1-1/8 on the base diameter and about 1-1/2" long

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #27 on: March 13, 2018, 10:55:41 PM »
The governer uses a "lollipop" which pivots under centrifugal force a bit and drives a dog on the inboard side which in turn, rotates a brass sleeve. The brass sleeve rides on a pin in a 45 degree slot in the sleeve rim. As the sleeve rotates, it moves in and out to actuate the governer latch arm. First step is to put a pin in the inboard flywheel hub for the sleeve. It was tight drilling and tapping the 6-32 hole. I need to clean up my slot in the sleeve a bit and make the pin a tad larger to get the most movement.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #28 on: March 13, 2018, 11:03:18 PM »
Cam and governer arm pivot assembly. The center threaded portion is offset about 50 thou  from the larger shaft to allow the gear lash to be adjusted. The pivot on the left was hogged from a piece of round stock.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #29 on: March 13, 2018, 11:24:57 PM »
To pour the bearings, I made a tee-shaped rig to align the bore perpendicular to the axis of the crankshaft. The saddles are spot drilled to hold the Babbitt and shims inserted under the caps and everything smoked with a candle. A sleeve the ID/OD of the saddle and shaft is inserted in the side opposite the pour to assure alignment. My old school Johnson forge melts the bearing alloy. I preheat the pour area to about 250F; spit sizzle or hand held IR pyrometer... The whole affair is repeated on the other side but using the poured bearing in place of the sleeve. Finished results are shown sans oil swipes and holes.

Offline Dave Otto

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Re: Myrick Eclipse one-third scale model part two
« Reply #30 on: March 14, 2018, 11:44:52 PM »
Nice work on the bearings Paul.
The engine is looking great.

Dave

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #31 on: May 07, 2018, 10:02:24 PM »
Have not posted progress in a while, other projects in the works. Wanted to show my detail on the hot tube burner. Rather than trying to drill a very small gas jet hole, I use a piece of 1/16" OD hobby brass tube which projects into the  fuel/air tube. This has the effect of drawing in air via a Venturi effect and is less prone to breeze effects. The tube is progressively crimped down at the gas pressure being used to adjust the fuel air mix. If you go too far, simply uncrimp it a bit. This is from my other working model of the same engine and so appears used. From light off, this heats the tube to red heat in 2-3 mins. My hot tubes on the models are 1/4" SS tube with TIG welded ends. I also use this on all my larger full sized engines. For the purists, this may be out of bounds, but for having a reliable draft insensitive burner, I'm happy with it.

Offline Myrickman

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Re: Myrick Eclipse one-third scale model part two
« Reply #32 on: May 28, 2018, 10:29:25 PM »
Well, with a box of completed parts, it was time for assembly. This one was tricky as the piston has to go in the cylinder from the bottom as the bottom of the rod will not clear the bore. Then the arch, supporting the cylinder is added. The crank was previously shimmed and fitted to the mains and disassembled. Since the rod journal is made from 3/4 drill rod, a dummy shaft was used to set the bearing clearance on the big end. I removed the rod cap and installed the crank on the cylinder and rod. Next, the whole affair was lowered into the block and mains and the mains caps installed. Everything fit nicely and the auxiliary exhaust port is cleared "just right" at the bottom of the stroke. Lot of fiddling with the governer to get it operational. There was one spot on the latch mechanism where it was rubbing a bit; an easy fix with a file. Base made from ~50 year old tongue-and-groove 3/4" mahogany. Valves still need some minor lapping to get compression up to par. Still have to finish making the cooling fan and plumb up th gas system. The tin shroud was made with new material and then made sweaty using the stuff you darken stained glass came with. She's a third scale and weighs in at about 65 pounds...about 1/9-th the weight of the full sized engine.

Offline jeff l

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Re: Myrick Eclipse one-third scale model part two
« Reply #33 on: May 29, 2018, 03:13:38 AM »
Nice work on the engine for sure .
I'm interested in how good the hot tube is going work and if it will be easy to light .I just finished a Reid engine which has a hot tube and it is difficult to light when it's cold.Jeff

 

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