Author Topic: Two Cylinder Engine  (Read 9607 times)

Offline fumopuc

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Re: Two Cylinder Engine
« Reply #60 on: May 20, 2018, 07:25:26 PM »
Hi Roger, I am still following along. I see also that your Proxxon tools are getting more and more. In my experience a good choice.
Kind Regards
Achim

Offline Roger B

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Re: Two Cylinder Engine
« Reply #61 on: May 29, 2018, 07:32:59 PM »
Thank you both  :ThumbsUp:

A few more bits on this one.
I machined the oil reservoir in the bottom half of the cam carrier, on the first version this was a separate component on the other side of the crankcase. I initially made the design 11mm wide with 3mm radius corners but decided that a quick cut with a 10mm end mill would work fine.
I then started on the water pump which will also be the support for the ignition system. First I drilled the various holes for the fixings and inlet and outlet passages and then drilled and reamed the main bore that will be used to set out the bores for the gears.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #62 on: June 25, 2018, 07:29:30 PM »
Due to all sorts of life things the next stages have taken some time  :(

The water pump body was set up on the mill to drill the idler gear bore and to rough out the cavities with a 10mm end mill. The main bore was then centred on the faceplate and the cavity and bore were finished using a 6mm 2 flute end mill as a boring tool. The idler bore was centred the same way and the cavity was bored out to 14mm. Problem   :facepalm: I had drilled the side port too deep and there was very little material between the two ports  :(  Time to start again  ::)
Best regards

Roger

Offline fumopuc

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Re: Two Cylinder Engine
« Reply #63 on: June 25, 2018, 08:11:00 PM »
Hi Roger, I feel your pain.
But the new one will be better, nicer and you will get it faster.
Why do I know this ?
Kind Regards
Achim

Offline Craig DeShong

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Re: Two Cylinder Engine
« Reply #64 on: June 26, 2018, 12:27:38 AM »
Been there, done that.  What I DIDN'T mention in my last Lauson post is that it took TWO attempts to carve a carburetor body out of a block of aluminum; but if you don't tell anyone I won't either, and they'll never know. :mischief:

One of the great things about working with bar stock is that you can always cut another piece and have another go.  Not like begging a new casting from a supplier (yea, and I've done that too).
 
Craig

Offline zeeprogrammer

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Re: Two Cylinder Engine
« Reply #65 on: June 26, 2018, 12:40:31 AM »
I hope this doesn't come across wrong...

It does us inexperienced, newbies good when the experienced have oopsies and tell us about it.

And it's just an oopsie.  ;D
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Roger B

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Re: Two Cylinder Engine
« Reply #66 on: July 11, 2018, 07:15:34 PM »
Thank you for the comments and support  :ThumbsUp:  :ThumbsUp:

Finally back to the water pump. As Craig said its just a bit more 20mm square aluminium and a bit of time not a catastrophe. I made a few changes to the way I made the cavities. In the first version I drilled for both shafts for the gears and then opened out to 12mm with an end mill. This had two problems, first the 4mm hole for the idler gear had a good chance of drifting slightly and second the 12mm endmill broke through into both ports and in the middle. This time I drilled and reamed the main bore and opened out with a 10mm endmill. I then moved across 12mm plunged nearly to depth with a 6mm centre cutting endmill (the biggest I have) and opened out with the 10mm cutter.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #67 on: July 11, 2018, 07:24:30 PM »
I then centre drilled and opened out the 4mm bore for the idler gear to minimised the chance of the drill wandering. After a quick check of the gear centres with some short lengths of silver steel I went back to lathe mode. This time I started with the idler side and using a 6mm endmill as the boring tool opened out the cavity to 14.2 mm diameter (to allow for expansion of the Delrin gears. I then centred the main bore and opened out that cavity with the depth stop at the same setting as for the idler cavity. Finally I bored out shaft hole to 9.8mm and reamed it out to 10mm.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #68 on: July 11, 2018, 07:25:09 PM »
And due to the 8 picture limit.
Best regards

Roger

Offline Admiral_dk

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Re: Two Cylinder Engine
« Reply #69 on: July 11, 2018, 09:29:44 PM »
Looks like you succeeded at last Roger  :ThumbsUp:

What can I say - I done my share of goofs lately - just not on engines, but it still bugs me  :-\
But I got my stuff done in the end like you.

Offline Roger B

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Re: Two Cylinder Engine
« Reply #70 on: July 30, 2018, 07:03:19 PM »
Thank you Per, remember that they are trial pieces not mistakes  :cheers:

I didn't have any long 4mm bore Oilite bushes so I turned the flange off one to make up the length. The next step was to drill the water inlet in the cylinder block and see how it all went together. As expected the connecting pipe will be a little tortuous but possible. I noted that the top fixing hole was closer that I liked to the cylinder block fixing. I decided to redrill it lower down knowing that it would interfere with the inlet flange. With a little hindsight there is no real need to flange the water connections, the horizontal engine works fine with the pipe Araldited in place. This will also make the connection between the pump and the block easier.
I received a small contact breaker from TS today so now I can measure it up and design the mounting.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #71 on: August 19, 2018, 03:20:26 PM »
On with the contact breaker. The mounting is made from piece of 3mm thick aluminium. The profile was cut the easy way with hacksaw and file.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #72 on: August 19, 2018, 03:30:32 PM »
Next up is the ignition cam. As this has an opposed crank the lobes need to be at 90░. I could have gone for a wasted spark system but fancied a challenge. The same techniques could be used for four cylinder system so it is not really wasted effort. The required shape was turned from 16mm silver steel. This was then marked with two horizontal lines 90░ apart and centered in the Keats angle plate. The angle plate was then offset 7.5mm and set vertical. The blank was then rotated until the first line was at 72.5mm (centre height + the offset). This was then turned down until the dimension across the cam was 14mm and the cross slide setting noted. The angle plate was set vertical again and the blank was rotated until the second line was at 72.5mm. The second cam was turned to the same setting as the first. The blank was then parted off and faced on a tapered mandrel.

Best regards

Roger

Online steam guy willy

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Re: Two Cylinder Engine
« Reply #73 on: August 19, 2018, 03:57:19 PM »
Hi Roger , may i ask you how you get the text onto the photos that you post ?? Engine build looking good.. Cheers

Willy

Offline Roger B

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Re: Two Cylinder Engine
« Reply #74 on: August 19, 2018, 04:07:32 PM »
Hi Willy, I use a photo editing programme to reduce the size of the pictures and when I am finished I go to 'Save As' rather than 'Save' and then type in the text. Some characters, like ? and . are not allowed so I always have to write 1 point 5 mm etc.
Best regards

Roger