View Full Version : More from Michael G
Anorak Bob
8th January 2015, 04:02 PM
An envelope arrived at home on Tuesday. In contained three 5mm wide racks and a length of brass pinion in some masterful packaging. Michael wondered if I had a use for them...I do and so will another bloke I know. :D Thank you Michael.
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simonl
8th January 2015, 05:19 PM
Were they made by you Michael?
What is the advantage of the helical shape to the rack and pinion as opposed to straight? Does it have the affect of a reduction?
Simon
Michael G
8th January 2015, 05:34 PM
I'm denying all knowledge Simon - this Michael G guy is an embarrassment to everyone else called Michael G on this forum...
However, the helical shape is just for smoothness. 20 degrees seems to be common with microscopes just because there is always a tooth in contact with the rack. If it were a straight rack then there would be a (slight) lack of uniformity converting the rotary motion to straight.
Michael
simonl
8th January 2015, 06:58 PM
I'm denying all knowledge Simon - this Michael G guy is an embarrassment to everyone else called Michael G on this forum...
However, the helical shape is just for smoothness. 20 degrees seems to be common with microscopes just because there is always a tooth in contact with the rack. If it were a straight rack then there would be a (slight) lack of uniformity converting the rotary motion to straight.
Michael
Maybe it's really Kenny G? :B
Anyway, you (i) do learn something new everyday! Constant tooth contact makes sense now you mention it. I love this forum. Never stop learning!
Thanks Michael, there will come a time when I will owe you an amount similar to a HECS debt with the amount of knowledge you (and others) have imparted to me!
Cheers,
Simon
Anorak Bob
9th January 2015, 02:03 PM
I'm denying all knowledge Simon - this Michael G guy is an embarrassment to everyone else called Michael G on this forum...
However, the helical shape is just for smoothness. 20 degrees seems to be common with microscopes just because there is always a tooth in contact with the rack. If it were a straight rack then there would be a (slight) lack of uniformity converting the rotary motion to straight.
Michael
20 degrees and smooth it is. Here's the rack on my recently acquired Nikon SM1 scope.
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