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Subject: Re: [Homebrew_PCBs] How to mark a gear to cut teeth ....any size offline

From: Rob <roomberg@...>
Date: 2017-01-08

I ran into this very same issue.
I did not have any gear making tools here set up that could just knock out a metal gear and
slip onto the motor D shaft.
After week of searching the internet I concluded that there was not any instant source to replace
my plastic gears unless I wanted to pay $75 for a custom made gear.
http://www.learnmorsecode.com/laminator/slowmotor.jpg
So I resorted to RC car gear suppliers and bought a pile of nearly acceptable gears.
I say nearly because I will have to drill out the smaller shaft holes to fit the lamnator.

 As far as designing gears being above your pay grade goes.....
We are pushing rollers in a laminator.
We don't care if we don't get it perfectly right.
Look up gear making on the web and you find guys making gears out of plywood
and guy making gears with hand tools.


On 01/07/2017 01:19 PM, Harvey Altstadter hrconsult@... [Homebrew_PCBs] wrote:
 

Rob,

Unfortunately, knowing the spacing of the gear teeth is only the beginning of cutting gears. After I looked at the geargenerator website, I realized that it had terms that were undefined, and as a layman, I could not use that site. I found the definitions of the terms in the Nomenclature section: https://en.wikipedia.org/wiki/Gear

At that point, I decided that designing gears was above my pay grade, and went back to searching for ready made metal gears. This is less difficult, if you can find gear sets having the same diameters and number of teeth as your original set. The gears don't have to be identical to your original gears, they just have to fit the space and mesh. The problem that I have encountered is that I have found a gear set that almost meets that description, and it is difficult, without physically trying the fit, to determine if there is enough slop in the fit to allow them to mesh with the existing shaft spacing.

The reason that the diameters have to match the existing gears in the HF laminator, is that the motor gear drives one of the roller gears, which drives the other. This is a hard mount, with no springs. This means that there is no adjustment available between them. The motor position has some small degree of adjustability, but if the roller gears don't mesh properly, the game is over. I am still looking to find the time to determine whether the plastic structure that supports the roller bearings can take temperatures over 200°C for extended periods of time.

Harvey


On 1/7/2017 10:45 AM, Rob roomberg@... [Homebrew_PCBs] wrote:
 

YES...better yet... IF YOU HAVE THE TECHNOLOGY
This geargenetator.com script only runs on-line
can NOT be stowed locally on your PC
AND
the reason I went to the trouble of documenting :
How to mark a gear to cut teeth ....any size... any number of teeth
http://www.learnmorsecode.com/gears/index.html

was because some of us have really bad internet connections that will not be getting any better any time
soon so PDFs and bigger better faster complicated javascripts running server side calculations  and YOUTUBE videos are off limits to these guys.....
soooo
drop back and punt.... go old school an show how to to it with a $10 calculator and a pencil.

I AM NOT a mathematician.
But a mathematician made a YOUTUBE video showing
SIN(DEG/2)2   read as: SIN of (degrees divided by 2) times 2 
will yield a number that you multiply the circle radius and have the distance to mark on whatever you are cutting... metal..plastic....  and I thought it would be best to know this method and share it.


On 01/07/2017 11:48 AM, 'K5ESS' k5ess.nothdurft@... [Homebrew_PCBs] wrote:
 

Better yet:

 

http://geargenerator.com/#200,200,100,6,1,0,0,4,1,8,2,4,27,-90,0,0,16,4,4,27,-60,1,1,12,1,12,20,-60,2,0,60,5,12,20,0,0,0,2,-563

 

Mike N.

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Saturday, January 07, 2017 12:33 AM
To: Homebrew PCBs
Subject: [Homebrew_PCBs] How to mark a gear to cut teeth ....any size

 

 

How to mark a gear to cut teeth ....any size... any number of teeth
http://www.learnmorsecode.com/gears/index.html