Author Topic: AOG’s version of Elmer’s number 5 geared engine  (Read 3254 times)

Offline AOG

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #15 on: April 30, 2019, 03:22:14 AM »
Thanks Bill, now onto the cylinder itself. I started by squaring up a blank. It was inserted into the four jaw and taken to length.



Then the blank was offset in the chuck and the bore drilled and reamed.



Next the end was turned round.



The part was removed from the four jaw and placed on a mandril. Then it was held in the collet chuck and the other end turned round.



The blank was moved to the mill where the mounting holes and the exhaust port were drilled.



The part was rotated 90 degrees and I drilled the exhaust holes and milled the valve slots. I screwed up one of the slots and ended up filling it in with JB weld and remaking the slot.



Then the steam chest mounting holes were drilled.



The part was turned on end and notch cut into both ends of the cylinder.



Then the passage between the valve slots and cylinder end was drilled.



While drilling the other side disaster struck. the drill bit broke about 3/4 of the way through the part. Worse yet the drill was carbide so the alum trick wouldn’t have worked. I was tempted to trash the part and start again but I decided to try to save it. A trench was milled from the valve slot towards the end of the cylinder on centerline until the top of the drill was met. Then using my smallest punch the remains of the drill were drifted out. Now I have a hole in the wrong place and a big trench in my cylinder. The holes were filled with JB weld and I will try again after it sets. Thankfully Elmer uses a brass valve plate between the cylinder and the valve. If I can get the JB weld flat enough to seal I should be OK.

Till next time

Tony


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Offline bent

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #16 on: May 01, 2019, 11:49:38 PM »
Argh!  That's the nightmare I have every time I go to drill cylinder passages...hope you can salvage the work you did already!

Offline AOG

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AOG’s version of Elmer’s number 5 geared engine
« Reply #17 on: May 05, 2019, 12:42:20 AM »
When last we left this build I had filled in the holes from my broken drill debacle with JB weld. The JB weld set and the excess was cleaned up leaving this.



the slot was recut and the port drilled. If you look at the picture you can see the remnants of the trench that was cut to get at the broken drill. I’m going to call that a successful save and move on.



The next step was to drill the cylinder cover mounting holes while the stock was still square.



With that completed the two of the sides were milled down to final dimension.



Then the corner between the two sides was faceted in preparation for rounding over.



The corner was rounded on the belt sander and all of the holes were tapped.



I’m going to end this with a family shot with the cylinder in it’s approximate final location. I need to order some longer 5-40 screws to finish mounting it to the base.



That’s it for now. Till next time

Tony


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« Last Edit: May 05, 2019, 06:27:45 AM by AOG »

Offline crueby

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #18 on: May 05, 2019, 01:12:05 AM »
Nice recovery!
 :popcorn: :popcorn: :popcorn:

Offline b.lindsey

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #19 on: May 05, 2019, 02:34:47 PM »
Nice save Tony, and that will all be hidden anyway. Gotta love JB Weld :)

Bill

Offline AOG

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #20 on: May 05, 2019, 04:59:36 PM »
Thanks guys

Tony

Offline bent

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #21 on: May 06, 2019, 09:12:26 PM »
Phew!  Good fix!  Gotta love JB Weld. :agree:

Offline AOG

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #22 on: May 13, 2019, 02:32:58 AM »
This weekend I got the cylinder covers done. I started by turning down a length of bar to match the cylinder diameter. Then I drilled and tapped the hole for the gland nut.



Having learned from painful experience, I always drill any kind of center holes before turning the profile. If you do it the other way around and the center hole is big enough there may not be enough material to support the stress from the drilling operation. In this case it’s not really an issue but I try to keep good habits. That brings us to the next operation turning the profile.



Next the bar was taken to the mill and the mounting holes drilled. I drilled them deep enough to make both cylinder covers without having to go back to the mill.



Both covers were parted off. Then the bosses were turned to fit the cylinder.



The last thing I did was to clean up the top face of the second cover. Here is a current family shot.



Till next time

Tony




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Offline b.lindsey

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #23 on: May 13, 2019, 02:52:57 PM »
Some nice progress there Tony!!  Keep it coming :)

Bill

Offline bent

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #24 on: May 13, 2019, 05:43:49 PM »
Good tip on the tapping prior to machining the boss.  Keep up the good work, Tony!

Offline AOG

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #25 on: May 20, 2019, 02:19:28 AM »
This weekend I got the piston and piston rod done. I started with the rod end. First I drilled the end 3/32 to take the piston rod.



Next I profiled the end to make it more aesthetically pleasing.



Then it was over to the mill to drill the end and mill it to width.



The part was cut off of the parent stock and rounded over. Then the piston rod was cut to length and the end was threaded.



The piston rod parts were put aside while I started on the piston. I turned down the OD 5 thousandths oversize to allow for trueing up on the piston rod.



Then I drilled and tapped the center of the piston.



The piston was parted off and screwed onto the piston rod. Then the rod assembly was mounted in the collet chuck. I am using a silicone o ring on the piston for sealing. Normally I cut the groove in the piston to the SAE dimensions for the gasket I’m using. This leads to a good seal but a relatively large amount of friction. I was reading the model engineer’s handbook and Tubal Cain recommends a different set of dimensions more appropriate to the lower pressures that model engines tend to operate. I cut the groove to the recommended dimensions and then trued up the outside and brought it to dimension. That also took care of any burs thrown up by cutting the groove.



The assembly was removed from the collet chuck and tested in the cylinder. It certainly has less friction but we’ll see how well it seals after assembly. The piston was unscrewed from the rod and set aside. The last thing I did was to solder the piston rod to the rod end. Here it is after the pickle and before clean up.



That’s it for now. Till next time.

Tony


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Offline AOG

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #26 on: June 02, 2019, 11:18:39 PM »
I’ve been out of the shop these last few weeks because of a back injury from working on my car. I’m up and moving again but it will be a while before I’m ready to get back to the shop. Unfortunately that means that this build is on hiatus until then.

Tony

Offline Ye-Ole Steam Dude

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #27 on: June 03, 2019, 12:17:00 AM »
Hello Tony,

Sorry to hear about your back problems. From first hand experience let me encourage you to take all the time needed to fully recover.

Have a great day,
Thomas

Offline b.lindsey

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #28 on: June 03, 2019, 03:05:33 PM »
No fun at all Tony. Take care of the back and don't rush as Thomas said. We will be here when you get back to the build.

Bill

Offline Admiral_dk

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Re: AOG’s version of Elmer’s number 5 geared engine
« Reply #29 on: June 03, 2019, 11:48:49 PM »
Get well soon  :LittleAngel:

Best wishes

Per