# 2 Mistakes

Discussion in 'Mistakes, Blunders and Boo Boos' started by 1Fitch, Jan 24, 2016.

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1. Jan 24, 2016

### 1Fitch

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Mistake #1

For Christmas my girlfriend wanted to get me a chucking reamer set I had looked at at one one point. Because I have been wanting to cut gears I asked for a dividing head instead. I directed her to the BS1 type that Grizzly sells. I knew there was a problem when I tried to move it and it weighed what felt like seventy pounds. I barely have 6" between centers. A BS0 type dividing head would have been much more suitable for my RF25 mill.

Mistake #2

I have cut a couple of gears using my new (over sized) dividing head. Once I understood the formulas involve for gear cutting and watching Tubalcains videos a few times I thought I had it down. The first couple of good gears I cut were all direct indexed. When I needed to cut a 35 tooth gear is when the trouble started. I'm 46 now and haven't worked with fractions for over 26 years. My calculation was 40/35 = 1 5/40 = 1 1/8 instead of the correct 1 5/35 = 1 1/7! I bolted on a plate with a 16 hole circle and away I went with 1 turn and skip two spaces. When I got to my last gear tooth, I was shocked!
To make this gear blank on my Sherline lathe requires I use riser blocks and care because this is really large for this lathe.

Back to 6th grade math class I go.:fan:
Enough of what a dummy I am for now.

Paul

2. Jan 24, 2016

### Swifty

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The dividing head should have come with a chart showing which plate to use and how many turns and holes for the required number of divisions.

Paul.

3. Jan 24, 2016

### portlandron

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Anyone that has ever cut a gear has a few "mistakes"

Regarding the dividing head that's not a mistake. Look at it as you have a dividing head to fit the new lathe that will some day replace your Sherline.

4. Jan 24, 2016

### xpylonracer

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Hi Paul

To save yourself a lot of headaches with which index wheel and number of divisions to use visit Marv's site and check for a simple dividing program, I can't remember the exact program name but there many there to choose from and most have a description, link to the site is
http://www.myvirtualnetwork.com/mklotz/

Emgee

5. Jan 29, 2016

### 1Fitch

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Thanks for the replies guys. Swifty, I found the chart you were referring to. I would have never thought to read the directions!:wall: Emgee, thanks for the link. There is good stuff there. I appreciate every ones input.

Paul

6. Jan 29, 2016

### bazmak

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Some are simple and costly and it hurts at the time

charlesfitton and gphunt like this.
7. Jan 29, 2016

### mcostello

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Some You remember the rest of Your life.

gphunt likes this.
8. Jan 31, 2016

### 1Fitch

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That's how we roll. Learn from our mistakes and keep moving forward. Thank you guys for taking time to read/respond to my post. You guys that have much more machining experience/knowledge than me are always an asset here on the forums.

Paul

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