Recent content by Charles Lamont

You are right on both points. I would add that 'similarity' as in similar triangles, is the key to the design. This has further implications. Firstly, and continuing throughout with the example scaling factor of 4, then the shoe or follower that the master cam rides on needs to be radiused at...

Mine grinder uses a white aluminium oxide wheel mounted on a home made spindle. I would not take anything like so agressive a cut with that wheel. In my case the cams are machined to about 0.005" over size (on radius), hardened, and then ground, taking cuts of 0.0005" and allowing it to run...

There is some more info on my grinder here: https://www.modelenginemaker.com/index.php/topic,9872.msg224859.html#msg224859 Couple of quick points not mentioned: The cams are rough machined, hardened, and Loctited to the camshaft in the correct orientation before grinding. The wheelhead, designed...

There are a couple of pictures of my camshaft grinder about 2/3 of the way down this page: http://www.charleslamont.me.uk/Seagull/camshaft.html It was designed to be (reasonably) simple to build and (mostly) economical in materials, and geometrically accurate. It is mostly made of aluminium...

I have made 2-piece delrin plug caps following Graham Meek's design. The design is clever, works well, and the result very neat. The little brass clip inside looks a fiddly job, but I did not find it as difficult as I expected. Find his write-up and drawing here...

Wellseal is a good liquid gasket. The method explained by Jens Eirik is exactly what I would have suggested, and means no intermediate port plate is needed. I would only add that if the two steam ports end up slightly different in the distance between the edges (height in Jens' terminology)...

Good point. I would not argue with your 16°. The chapter on 'Turbulent Flow in Pipes' says the disturbance to the flow dowstream of an inefficient fitting like a globe valve may persist for for 50 or more pipe diameters before it sorts itself out. On the other hand, in the case of a straight...

That looks better to me, but we seem to have our wires a little crossed. I was indeed talking about the exit taper, and I did mean 10° included. For the entry side, I was trying to suggest that you do not actually need to have any a taper atall if you have a bell mouth and the inlet path is...

Perhaps counterintuitively, a sudden or rapid expansion is 'lossy' while a rather rapid contraction isn't. The bell-mouthed entry to a carb is efficient, and a shallow taper entry not as good. But the reverse is true on exit from the venturi. A taper of about 1 in 6 in dameter, or 10° included...

And a ball handle for engaging the thread dial indicator! Alan, that is classy.

Simple jobs, generally no. With a complicated part yes. Castings often need considerable care in finding a finished part inside them, sometimes involving compromises. After a careful survey, I may take initial light cuts just sufficient to create datum surfaces. These allow measurements to be...

Terry, not sure about the arrangement of your crankshaft that caused problems with the installation of the oil seal, but going back it looks as though you had to get it over a shoulder. If that is correct, and in the unlikely event that you had not thought of it, could you have used a temporary...

I can back up what George and Ian say. I made a small one with wiper dies, though I did not know that was what they are called. It works well. One surprise was just how tight the bearing clamp bolt needs to be

Nice to have one still working. I think the one I had was a 33E. I reluctantly gave up on it after it had to be sent back several times for a faulty power slide switch. I found a good landing involved free fall until the last possible moment and then full retro.

I'm impressed.