Tool Starrett Gear Calipers

[140mower]

I thought that rather than plug up @David_R8 's shenanigans thread I would bring what little I know over to a place of it's own.....
To be honest, I have not used them yet, I first spotted them on Craigslist when I was making the gear cutting attachment for the shaper, but were priced out of my range. Fast forward about a year and they had come down in price to something I figured I could deal with should SWMBO find out. By then, I had made my gear and it was merrily going roundy round inside the feedbox in my lathe.....

HOWEVER! He says with a finger pointed to the sky, making little circles....... I have a book, and the book tells me that it's used for measuring gear tooth thickness at the pitch line.

Last two images are courtesy of the book "Precision Measurement in the Metal Working Industry"

 

[140mower]

@Dabbler ..... I agree completely on the cool factor, not to mention that not many people have one. Which is why it really came into my possession...... What can I say, I am little more than a two bit tool whore.....

 

[Dabbler]

me too!

 

[6.5 Fan]

What can I say, I am little more than a two bit tool whore..

It helps if it's shiny too.

 

[Mcgyver]

Another must have for the complete toolbox

 

[Susquatch]

I want one too!

The cool factor is priceless!

Kijiji is gunna have a meltdown!

 

[140mower]

I want one too!

The cool factor is priceless!

Kijiji is gunna have a meltdown!

Just don't price out a new one unless you are sitting down and your heart pills are close by and handy......

 

[Doggggboy]

91 C$ Walmart but 4435C$ for Starrett at Grainger

 

[Susquatch]

91 C$ Walmart but 4435C$ for Starrett at Grainger

4435 is clearly in the make one instead category.

 

[Aliva]

https://www.aliexpress.com/item/1005002984856051.html?spm=a2g0o.productlist.main.23.6014298cv6qHJ7&algo_pvid=0fb63710-204d-4fad-8231-bfa30664accf&algo_exp_id=0fb63710-204d-4fad-8231-bfa30664accf-11&pdp_npi=3%40dis%21USD%2156.41%2138.92%21%21%21%21%21%40212248ba16811313121662497d06d3%2112000023066043982%21sea%21CA%210&curPageLogUid=Z4HTBicMX4qq

 

[Ironman]

Well, well. Live and learn. I never even imagined a tool like this, never mind being able to afford it.
I've only cut 5 gears in the last 5 years so it would take up valuable space, and never get used unless I could not identify the gear tooth. Now with the internet profile charts I have found it easy to match up a gear.

 

[Mcgyver]

https://www.aliexpress.com/item/1005002984856051.html?spm=a2g0o.productlist.main.23.6014298cv6qHJ7&algo_pvid=0fb63710-204d-4fad-8231-bfa30664accf&algo_exp_id=0fb63710-204d-4fad-8231-bfa30664accf-11&pdp_npi=3%40dis%21USD%2156.41%2138.92%21%21%21%21%21%40212248ba16811313121662497d06d3%2112000023066043982%21sea%21CA%210&curPageLogUid=Z4HTBicMX4qq

thats more like it. I've got the Starrett, but paid the Ali price

 

[trlvn]

with the internet profile charts I have found it easy to match up a gear

You can't throw out bait like that and not expect some of us to rise to it!

Link please!

Craig

 

[Susquatch]

thats more like it. I've got the Starrett, but paid the Ali price

Do you really need to rub that in! . Yes, we are all jealous!

I did a bit more digging and spotted a different color (rolling my eyes) with an electronic option for those who hate verniers.

Gear Tooth Vernier Caliper

https://a.aliexpress.com/_mtwgoVq

If I did get one (Yes, I'm thinking about it), I'd prolly go vernier for the reliability. I guess I just don't trust Ali that much let alone Ali digital just yet. Of course I wouldn't be expecting Starret or Mitutoyo vernier quality either. Prolly good enough for measuring gears though!

 

[Tom O]

Here’s my Brown and Sharpe

 

[Ironman]

You can't throw out bait like that and not expect some of us to rise to it!

Link please!

Craig

Oh, okay.
Go to https://evolventdesign.com/blogs/history/gear-identification-template and download the chart for $5 or...
More info on sae https://omnigear.us/?page_id=160

I had the SAE profile chart from evolvent and the file is corrupted and won't open so I could only post the metric stuff. I do not know if the DP chart I posted will stay true when printed, should be a pdf.
Here is a diametrical Pitch chart

https://www.bostongear.com/-/media/Files/Literature/Brand/boston-gear/catalogs/p-1930-bg-sections/p-1930-bg_engineering-info-spur-gears.ashx

 

[Mcgyver]

Do you really need to rub that in! . Yes, we are all jealous!

They're an oddball, not much supply and not much demand. Fairly specialized and I'd guess they would be a company supplied them. It makes the market quite lumpy if not binary lol so you wait for a low point. Looks like they are discontinued as well. So many gear manufacturers have gone away. (I remember the Toronto Gear auction, massive 8' dia wood patterns pulled out of the lofts and rafters. Quite a place.)

They are not going to do you any good to identify a gear (or pressure angle), you have to know the addendum to use it. (figuring out the DP is simple : # teeth + 2 /OD). Where they are useful is for inspecting whether you've gone deep enough with a gear you are making. Necessary if you are doing QA, but countless home shop gears have been well made by carefully touching off the cutter and relying on the feedscrew to get to the right depth.

A slow lane project of mine is a gear hobbing set up where I think it will be of benefit, so picked up for that...and also, if its cheap and I don't have, I buy it. 30 years later you end up with a lot of stuff lol

 

[Susquatch]

They are not going to do you any good to identify a gear (or pressure angle), you have to know the addendum to use it. (figuring out the DP is simple : # teeth + 2 /OD). Where they are they are useful is for inspecting the whether you've gone deep enough with a gear you making.

Ya. I know. I've made lots of gears without one. Truth is that I have no slightest clue how to even use one.

This is really just about cool factor...... If only it were chromed......

Some poor soul: "What the hell is that thing?" Me: "It's an IQ tester. You put the sharp end up your nose until it hurts. Then read your IQ on the vernier part of the scale....... ...... Seriously, it's a Gear Caliper, lemme show you how it works....."

Even if I had one I'd prolly never use it.... LOL! Way too much fun!

Ya, I'm jealous!

 

[StevSmar]

thats more like it. I've got the Starrett, but paid the Ali price

And it’s made of stainless steel! I’ve decided I’ll no longer buy anything unless it’s stainless or satin chromed…