Author Topic: The "Little Pearl" Single Cylinder Marine Engine  (Read 74202 times)

Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #150 on: August 20, 2017, 01:23:02 AM »
Thanks Don. Yeah I know you have been getting a LOT of rain down there, more than needed I am sure. Maybe it will help the crawfish population :)

Bill

Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #151 on: August 20, 2017, 06:03:04 PM »
There are several smaller parts that require some threads that I don't have dies for and really don't want to buy the dies since they aren't sizes I use often...5/8-18, 1/2-20, etc.  Probably two years ago I had purchased the Sherline threading attachment for the late and had never even opened the box so this was a perfect time to give it a try. The simplest of these parts to do a trial on was the plug for the piston valve that plugs up the bottom of the through hole in the cylinder. This is just a simple cylinder threaded 5/8-18 on the OD and with two pin holes on one end for a pin type wrench for installation purposes.

Not the thing about the Sherline threading attachment is that you have to remove the motor/speed control from the lathe so before doing that I chucked up a piece in the 3 jaw and turned it to the 5/8" diameter required (photo 1). Then the motor was removed and the rest of the threading attachment with the proper gear train for 18 tpi was added to the head end of the lathe (photos 2,3 & 4). The spindle is then hand cranked to single point the threads, which are shown part way cut in photo 5.  Once the threads were cut I left the part in the 3 jaw and took it to the mill to add the two holes for the pin wrench (photo 6). Finally the part was parted off from the parent stick and the cut off end faced to the final thickness required. The finished part is shown in photo 7.

Bill

Offline zeeprogrammer

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #152 on: August 20, 2017, 11:18:02 PM »
Still here Bill.  :popcorn:

Say...are we getting close to a family shot?
Or did I miss one.  :-[
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #153 on: August 20, 2017, 11:52:28 PM »
Zee, just some partial family shots of sub assemblies so far. I need to get the base done and that isn't Sherline work. I'll get there before too long and provide a family shot.

Bill

Offline zeeprogrammer

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #154 on: August 21, 2017, 12:35:11 AM »
No rush.  :stickpoke:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Online Kim

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #155 on: August 21, 2017, 05:15:07 AM »
That's pretty neat Bill!  Glad you finally got to use your threading attachment.  I've never seen it setup, only heard about it. So its nice to see it setup and working!  Glad you shared those pictures with us.  Back before I had my Grizzly lathe, I was trying to figure out how to make something like that for my Taig. Never did, but it's really nice to see the Sherline in action.  And quite nice results too!

Kim

Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #156 on: August 21, 2017, 11:44:41 AM »
Thanks Kim. In actuality it was far easier to set up and use than I had imagined, still not as easy as quick change gear box, but for the odd single pointing task not too bad.

Bill

Offline steamer

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #157 on: August 21, 2017, 11:59:04 AM »
This is all coming together nicely Bill!   

Dave
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Damned ijjit!

Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #158 on: August 21, 2017, 12:06:59 PM »
Nice and slow Dave, but I'll get there :)

Bill

Offline steamboatmodel

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #159 on: August 23, 2017, 01:18:34 AM »
I am always amazed at what can be done with the smaller lathes, have a Emco compact 5 myself and though you can do threading under power with it I always turn the motor off and crank it around by hand.
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Gerald.
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Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #160 on: August 23, 2017, 01:28:55 AM »
Thanks for looking in Gerald. I can thread under power on the Cowells lathe but the change gears are for metric threads, and since I had the threading attachment for the sherline, I figured it was about time to use it. I was pleasantly surprised.

Bill

Offline crueby

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #161 on: August 23, 2017, 01:38:32 AM »
The threading came out nicely - I have the attachment for my Sherline too, but the time spent removing/replacing the motor and speed control wound up keeping me from using it for anything but really large threading sizes, and once for a winding drum on a clock (used a round tip to make a shallow depression, large pitch, to guide the cable around a 3" drum).
Maybe we can work out a way to extend the tubes that the threading attachment goes on to allow the motor to stay on when using it (just with the motor OFF!)

Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #162 on: August 26, 2017, 06:07:33 PM »
While I still had the threading attachment out I machined up the piston valve packing gland this morning. It needed the same 5/8"-18 threads on the OD and the plug machined a few posts back so the gear set up was the same. This part also requires 7/16"-20 ID threads on one side but I had a tap for that. I decided to do the internal threads with the tap first and machined everything on that side of the gland first (photos 1 & 2). Once reversing it you can see there wasn't much to chuck on, but it was enough cut the OD threads slowly taking about .003-.005" at a pass (photo 3). Using the tailstock gave good support for this also. Photos 4 & 5 show both sides of the finished gland and the last photo shows it with the packing nut screwed in as well. Only one more of these parts to go and that is the piston stuffing box packing nut. Should get that knocked out this afternoon.

Bill

Online Kim

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #163 on: August 26, 2017, 06:11:17 PM »
Your packing gland looks pretty sharp there, Bill! Nice work!
Kim

Offline b.lindsey

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Re: The "Little Pearl" Single Cylinder Marine Engine
« Reply #164 on: August 26, 2017, 06:15:12 PM »
Thanks Kim. The thread cutting attachment works a lot better and for that matter easier than I had suspected. The savings on the two dies I would have needed (and didn't have on hand) defrays most of the cost of the attachment and I m pleased with the results.

Bill

 

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