MadModder
Gallery, Projects and General => How do I?? => Topic started by: AcieraF3 on November 16, 2011, 06:48:48 PM
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I have almost finished building an Elmers 25 wobbler engine. The only thing I need to do is drilling the port hole in the cylinder. I was triggered by this discussion in Spuddevans project report:
Now, I went back and looked at your cylinder with the pivot in it. Are you going to forget to drill the entery hole for the air into the cylinder? :poke: Just wondering. :)
Well spotted!! Actually I deliberately have not drilled it yet. I figure on assembling the whole gether, positioning the crank so that the cylinder is in the right position for the exhaust hole in the frame to line up with where the inlet hole is meant to be on the cylinder, and then spotting through to accurately mark up the postion. Does that make any sense outside of my head?
Tim
My question is: what is the position of the crank so that the cylinder is in the right position for the exhaust hole. A sketch would be very helpful.
thanks all :Doh:
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My question is: what is the position of the crank so that the cylinder is in the right position for the exhaust hole. A sketch would be very helpful.
Hi there AcieraF3 :wave:
I'm not sure if what I did was the correct way, but it worked for me. What I did was to assemble the engine, and position the crank with the crankpin at the very top of its rotation. That will position the cylinder at the right angle. Then I just made a little mark with a drill held in a cordless drill, guided by the exhaust hole in the frame. Then I dissasembled it and then drilled the inlet/outlet hole in the cylinder on the mill.
It may not have been the proper way, but it worked for me.
Let us know how you get on, even better, take some pictures and show us :worthless: :D
Tim
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The correct position of the crank for alignment, is at 70*. Not the 90* that most engines are drilled at....... :scratch:
This gives an overlap of the holes, allowing longer opening time of the port. :thumbup:
David D
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The correct position of the crank for alignment, is at 70*. Not the 90* that most engines are drilled at....... :scratch:
This gives an overlap of the holes, allowing longer opening time of the port. :thumbup:
David D
David, what do you mean exactly by 70 degrees. A small sketch would be very helpful. :Doh:
thanks
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The correct position of the crank for alignment, is at 70*. Not the 90* that most engines are drilled at....... :scratch:
This gives an overlap of the holes, allowing longer opening time of the port. :thumbup:
David D
David, what do you mean exactly by 70 degrees. A small sketch would be very helpful. :Doh:
thanks
Ace.
I really hoped you wouldn't say that! :palm:
Please excuse the 'orribly horrible scribble........
(http://i110.photobucket.com/albums/n95/Dayjo/P1010761.jpg)
Drilling the valve plate at the 70 degree position, allows the cylinder port to slightly pass, (but not close) the valve port, before returning. Giving a longer opening time..... :thumbup:
Hope this makes sense! :scratch:
David D
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:clap: What do you mean horrible. It is great and very clear. Thanks very much, I will drill the port this weekend hopefully and show you a runner!!?
Teun
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To mark where to drill the holes when I did mine, it took a tiny piece of shapened rod and stuffed it into the port in the cylinder wall--so it protruded only a tiny amount. Then bolted it all up and spun the crank a few times so I got a small scribed line. Then I just drilled the holes at the ends of the lines.
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I may be seriously confused (usually am :palm: ), but why not just use Elmers drill jig? :scratch:
Jeff
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I agree with Jeff. Elmers drill jig has worked just fine for me and in fact it is one of the attractions of this design for the newbie.
John-Som
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Jeff and John-som, I did use the jig but I thought is was only an aid for drilling the ports in the stand and not in the cylinder. Probably I am confused now :scratch:
teun
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Yea, he didn't explain very well. For the cylinder you put the piston/rod in the cyl, put the jig on the pivot, and use a piece of rod/drillbit through the 3/32" jig hole and connecting rod hole. This lets you drill the 1/16" hole in perfect alignment with the port holes.
Hope that makes sense.
Cheers
Jeff
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It makes perfectly sense. I was already wondering where the second 3/32 hole was for. I should have thought a bit out of the box :doh:
thanks Jeff.
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:D :ddb:
Thanks for all your help; I did it, it is a runner!!!!!!!!!! I have made a very crude movie to prove it. The next job will be blinging.
Teun
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YEeee...... HAaaaaarrrrrrrrrr :ddb: :ddb: :ddb: :ddb: :D
It's alive! Well done Teun! :clap: :clap: :thumbup:
David D
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Nicely done Teun!!! :clap: :clap: :clap:
Cheers
Jeff
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Well done Teun :clap: :clap: :clap:
I fixed your link to embed the video into your message.
Tim
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Nice, congrat :clap: :clap:
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Well done Teun :thumbup: :thumbup: :clap:
Great fun to have that first runner isn't it ? :D - It becomes addictive :D
:beer:, Arnold
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Thanks again
Arnold you are right it is addictive. any suggestion for a follow-up project
Teun :proj:
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:lol: I know just how addictive it is :ddb: :ddb:
Hmmm... For a follow-up, it's difficult to recommend something. It depends on what you'd like, and what skills you'd like to improve.
If you want to work a bit on the bling factor, Elmer's Fancy is a great build.
If you want to test your skills at making something small, Tiny is a great little engine.
For a really nice, but longer-term project, I can really recommend the Grasshopper.
Then there's also always the option of making a bit of tooling you need :thumbup:
My best advise would be to follow your heart and build something that draws your interest and that you really want to build :dremel:
:beer:, Arnold
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After I built the #25 I chose to go for a more challenging build, Bog's Paddleducks twin marine engine, build log here:- http://madmodder.net/index.php?topic=1525.0 and the plans can be downloaded here :- Click me (http://www.timevanswindows.co.uk/spuddevans/images/Paddleducks.zip)
Even if you don't want to build it, the plans are well worth reading through, many good hints and tips are there.
Tim