Pin Gage Question

[Pevehouse]

I use my .061" - .250" set and my .251" - .500" set about equally. I use them for more purposes than to check hole diameters so having the complete range is useful for me. The smaller set is less expensive so maybe the first one to buy. I would like to add the .501" - .750" set but the cost is significantly higher. I had written in a previous post about combining three pins to measure over range holes which gets me by. https://www.hobby-machinist.com/thr...o-extend-measurement-range.96790/#post-903491

As mentioned above, when I am measuring runout, I usually use wrist pins. They are dictated by their use to have a tight diameter and straightness tolerance. A local small engine shop, marina, or implement dealer would be a good source.

As far as wrist pins go, I have plenty of those. I’m an Automotive technician and a professional engine builder. Just never thought about using a wrist pin till you mentioned it

 

[durableoreo]

I think the price difference is mostly about segmenting the market. The fancy stuff probably is a bit more reliable but for most work, I bet the cheap sets are good enough.

I'd advise you to buy the 2 smaller sets. Search for "B07GX4PDNY" on Amazon. The importer (HIPP) seems better than most.

I got the whole set from Shars (which weights 400 lb) and I don't recommend it unless you like paying for freight and re-arranging the shop.

 

[rabler]

As a side note, when there's any chance of wear or abuse, I grab a dowel pin rather than a gage pin. Same idea as using a wrist pin. I keep a few around in standard sizes. No where near the range of sizes and perhaps poor tolerance, but a good way to put less mileage on the precision stuff. Accurate enough for doing things like verifying basic runout in a collet or chuck setup, centering pins, etc.

 

[woodchucker]

Ii see its already been asked.

 

[woodchucker]

As a side note, when there's any chance of wear or abuse, I grab a dowel pin rather than a gage pin. Same idea as using a wrist pin. I keep a few around in standard sizes. No where near the range of sizes and perhaps poor tolerance, but a good way to put less mileage on the precision stuff. Accurate enough for doing things like verifying basic runout in a collet or chuck setup, centering pins, etc.

Same here, and mine only go to. 250 so the dowel pins go to 3/8

 

[7milesup]

Who did you do the training through? I’ve been self teaching myself GD&T for the past 10 years, but it would be helpful to take a class. I was going to register for a class through the community colleges here in CT, but don’t want to drive 1.5 hours each way for the next few months.

The "local" community college drove to our production facility and taught us there. Quite convenient! Yeah, 1.5 hours each way is a haul, even coming from a guy who drives 45 minutes to work.

 

[projectnut]

The "local" community college drove to our production facility and taught us there. Quite convenient! Yeah, 1.5 hours each way is a haul, even coming from a guy who drives 45 minutes to work.

That’s one of the advantages of living in Wisconsin. Over 10 years ago the technical college system saw the light that we were in dire straights as far as not being able to fill open positions in the machining industry.

Many of the counties stepped up and rejuvenated their training programs. When we hired new maintenance technicians they were required to take training courses at the local campus. The company paid the tuition. It made a big difference when they could read and understand machine blueprints

 

[Ischgl99]

The "local" community college drove to our production facility and taught us there. Quite convenient! Yeah, 1.5 hours each way is a haul, even coming from a guy who drives 45 minutes to work.

That works out nice for you. We have a number of community colleges here in CT that offer machining courses, but the two that are within 45 minutes of me are not offering the classes I want to take this semester. I’m hoping they offer more in the fall, I didn’t think to check last summer. I want to also take a class on metrology, but that too is 1.5 hours away. It’s relatively close to where my son is going to college, so could be an excuse to visit him, but he might get sick of me dropping in

 

[mountainshadows]

Thanks for all the replies. It is much appreciated.
I bid on a Vermont .251 to .500 set on eBay. I should have put a higher bid in than $120. They sold for $122....hahaha.
That set goes $300 brand new.

I'll keep on the lookout and try to make my mind up. I have a few weeks away at work yet so there is time.

 

[Deleted member 69715]

I would expect that the straightness falls into the over/under, otherwise the pin would not register correctly. Imagine a -.0002 being bent by a slight amount, it would now be a + size, and be out of spec.

I've got import sets from Shars. .011 to .500 by .001" & up to .0002 under. I've used them more than I ever thought I would. By using two pins, I can measure to 1". I've measured them with a micrometer and they have been very good. Good enough for my use. I don't have a way of measuring small holes by any other means. They are very helpful when trying to get a press fit sized. Used way more often than my gauge blocks.

What I did when I did calibration of tools for an aircraft part mfgr. was calibrate whole sets of pins. .015" (?) to .500". We had seven or eight (can't remember) through out the shop. Once a year.
In addition to the normal measuring of the diameter I had to "roll test" them on a surface plate. That's how I found bent ones. Criteria was any light between the pin's diameter and the plate was cause for rejection.
I'm retired now for 10 plus years. Don't drink like I used to.