Poppin Double

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ShedBoy

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I have decdided that I am going to make my partners Grandfather a motor for his birthday which just happens to be on christmas day. I never give him a xmas present but he always gets a birthday present. I have decided on a Poppin engine because it is easy to run, just needs metho. Also decided I was going to make two of them just incase I kill one in the process or if all goes well I will have one to keep.

Had some suitable hunks of aluminium lying around that needed cleaning to size

Does not take much longer to make two. Reaming the pivot hole. Some things are being changed to metric to suit tooling.

Drilled some holes where required. There is a bit of an error which I didn't pick up because I am using a different size bearing and did not make allowance for it but I can save it with some clever shaping when finishing the standard.


This is how they sit at the moment. They are quite small these engines.
More shed time tomorrow :)

Brock
 

lazylathe

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Will be following along Brock! ;D

Love the look and sound of these engines.

Andrew
 

ShedBoy

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Well I come down with the flu last night which is not handy. Heater behind me in the shed and away I plod. Got to a point where I need a drilling jig so I took a break from the blocks and made a start on the heads and said jig.

Turned and centre drilling some stock and moved it to the rotary table.

It has all been drilled deep enough so I can part off both heads and have some left over to make the drilling jig for the standards and the cylinders. Hole size is 2mm. I still hate drilling small holes but I succeeded with no breakages :)

Brock
 

ShedBoy

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Got more done today. not feeling real good but nothing better to do :)

Vacuum chamber in head I suppose. I think it is stainless but turns nice.

Lapping begins


Heads are all but done just need a final clean up.

Made a drilling jig it is 5/8 one side and 11/16 the other so it can be used to drill the standards and the cylinders.

Had to tap the oppisite end of the standard to tighten the jig down.

Like so

Took minutes to drill both. Simple :)

Turn another spigot while I was at it and moved the chuck to the table again, drilled out the thread and bolted the standard to the table and machined the front where the cylinder mounts.

Easily finished later on. I have made a jig to hold through the bearing and will start shaping the bearing stands tomorrow, then hog out the unwanted bits, instal the clamp bolts and it will just need finishing. Thanks for looking in. :)

Brock
 

fcheslop

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Hi Brock,Nice build. Poppin is a great engine to make when I made mine I added an 1/8 or 3/32 to the length of the cylinder and turned a spigot on the end to engage in the frame just to keep every thing in line.
They are great fun,good luck with the build the best cure for flue is a good double or two :big:
best wishes Frazer
 

NickG

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Good idea that Frazer, I found it difficult getting that spot on.

I also made two Brock, one for dad ... although they didn't get finished at the same time, I got bored of making 2 of everything! The first ran that well though that I did go back and finish the other for myself and that was just as good! Both ran first time just setting the cam by eye ... Couldn't believe it considering the struggle I had with my Jan Ridders version ... Think I learnta lot from that one though. Enjoy the build, looking forward to watching it unfold!

Nick
 

ShedBoy

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Thanks for the tip Frazer, I will hopefully make a start on the cylinders later today. Not looking forward to the 2mm tapping :-\ slow and steady
Nick, I have a mistake part which I have at first, it has only suffered one mistake so far but still quite useable. Making two at a time saves with set up time. The sun has come up and I am feeling better so some chores then into the shed.

Brock
 

ShedBoy

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Well I didn't make a start on the cylinders yet ;) but got all but the final finishing done on the standard. Afetre the lapping yesterday my fingers refuse to do it.

Machining the bearing uprights

Set up to machine the cylinder upright to thickness

Nearly look like standards

First one done with more than 1 mistake now but still useable, the 2mm threads pulled out (steer clear of Garvin taps, had nothing but issues with them) so they were upped to 3mm.



The second one came out good and added some good looks to it. They just need some sanding and filing and wet and dry and polish to finish ::). Will do all that when I have stopped fitting parts to them while building. May even go into the shed again today and start on some cylinders maybe. Might do some easy little bits. Thanks for looking in.

Brock
 

ShedBoy

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MAde a start on the cylinders last night. Cast iron bar and a home made tool on the tool grinder, it works great.

Lots of notes and instructions

Cast Iron bar and 0.047 wide tool

One done. Will start on the boring later and lap it to size. I am just going to use a piece of copper pipe held in my hand.
Brock
 

tvoght

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I know any variation on the spacing of those fins would stand out like a sore thumb, and it looks like you nailed it!
--Tim
 

ShedBoy

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I stressed alot making them fins as I have no DRO, I just locked saddle in place and used the topslide to move towards the chuck. I have been too sick to go outside for the past day. I may try to get out there this arvo if I feel better.

Brock
 

ShedBoy

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Well I have been out in the desert acting like a wombat for another week so it is back to real work now.

My lash up for drilling

Spot at 2mm on the drill press

Drill through 1.6mm on the mill, just held by hand and worked fine

Tapping 2mm, smallest tap I have used so far


The easiest way I could figure to get the holes in line, pick up one threaded hole and move the guage around and mark the same side on the other end. Quick, easy and seems accurate.

Second cylinder with one booboo

Lapping paste from CTC Tools, whole lot under $10.


Hand held copper pipe, I started with fine valve paste and worked my way down. The hand held stick is so simple to use and and I managed to get the bores
within 0.01mm end to end. Pipe has a good feel to it worst part is the razor sharp corner on the end of the bore. Need a longer bit. Turned at about 325rpm.

Brock
 

ShedBoy

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Bolted the cylinders on for a photo shoot.



That is all for now, should get a full day tomorrow as it is raining supposedly :)
Thanks for looking in.
Brock
 

NickG

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Good idea to get the holes right Broc, that's one of those daft little things I struggled with!
 

vcutajar

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Brock

Still following this interesting build.

Vince
 

ShedBoy

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I have been lazy but it is nearly xmas so I thought I should show what has been happening in my neck of the woods.

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