I recognize that aircraft hardware holding those cases together...................
Chopped Twin Running At Last!
- Thread starter Pushrod Twin
- Start date
I know test flights after dark are not allowed, but there was enough light on he outbound leg to see adequately, & besides, the lights needed testing & adjusting sometime. It's a beautiful autumn evening out there, the biggest hazard is grape trucks. Harvest has started in the surrounding vineyards & the overloaded lorries tend to drop slippery grapes on he roads at intersections. Head light works well & the mag works perfectly. Confidence is building again, I think we are safe to cross the ditch for a foray North.
It's a beautiful autumn evening out there, the biggest hazard is grape trucks. Harvest has started in the surrounding vineyards & the overloaded lorries tend to drop slippery grapes on he roads at intersections. Head light works well & the mag works perfectly. Confidence is building again, I think we are safe to cross the ditch for a foray North.
Yes Bill, different frames do have different vibration characteristics & some people recommend a change in balance factor when changing frame types. I accepted Terry's crank as it was, added my pistons & took my chances. I may go through the weighing & adding or drilling performance, if I need to go back in there, as I did when I built the motor the first time.
I will make a pair of flywheels for my B motor, they will be replicas of standard Vincent ones but from normalised SAE4340 because I have a pair of rods I matched & a pin & a new mains spindle etc. That set will get the balance calculations when the time comes.
I will make a pair of flywheels for my B motor, they will be replicas of standard Vincent ones but from normalised SAE4340 because I have a pair of rods I matched & a pin & a new mains spindle etc. That set will get the balance calculations when the time comes.
I wish I had your tools, I am trying to weld and rebore the bigend of my Comet to 102mm Stroke = 560 ish.
But checking the two wheels together before I do anything, The two wheels don't match up !.
If I align the old bigend holes, The balance holes don't, I can see it by eye.
I think I will set the balance holes inlign then bore the bigend.
David Bowen told us the other day, The Flywheels were bored one at a time back at the Factory, I am going to try welding the 2 wheels together, And making one pass, I know I will cock it up, but must try.
Fingers Crossed, Bill.
I admire your pluck Bill but with my admittedly limited knowledge of rotating masses and building flywheels I would have thought that the entire mass of both flywheels would give the resultant force individual alignment of balance holes would not matter after all you balance the whole assembly not each side I would align the big ends and not worry about the holes so long as they are not a mile out. but there is sure to be someone on here who knows a lot more and can shoot me down in flames if necessary
It's not the balance that bothers me, Don't you remember the holes I drilled in my Light Twin Flywheels !!.
But If I mess up the Bigend holes, The mainshafts will be out of alignment.
If it goes wrong I have another pair of wheels and shafts, So I will just build a 500, We will see.
Cheers Bill. From a White Dorset !!.
I'm not the person who knows a lot more but if the flywheels are balanced differently compared to one another there will be a dynamic out of balance that may cause unwanted loads in odd directions. You can get these unexpected forces in wide car tyres that are poorly made and one side of the tyre is heavier than the other. When fitted to the front wheels alternating axial forces can make the steering wobble. (I experienced this when I had some "cheap" tyres fitted.
) Dynamic balancing can cure or alleviate these problems.
I feel the outer rims are about right with the balance holes inline, I have made tubes to go in those, To hold them while welding, And I am boring the bigend, So It might work ?????. Cheers Bill.
Bill can you just bore the hole offset and use like a 40 mm parallel pin without nuts either end, you know, heavy press fit type. Cheers..................Greg.
Thanks Greg, But I am just a Backstreet Bodger, Doing things on the cheap, I don't have skill or the tools, It's just something I have always wanted to do, If it works I will be 10 feet tall !, If not I will be a silly old sod,
Odds On the latter !!. Cheers Bill.
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