Anyone know where I can get hold of ‘Gauge Rods’

[Chris TickTockParticipant @christicktock]

Hi guys please forgive me for as I get a lot of help / advice from our US friends sometimes the different jargon gets confused. What I am looking for is precision ground small round rods to use to hold against micro items being machined to assess whether it is the right length. Yes there are many alternatives to measuring micro items but i like the sound of this method and wish to source suitable gauge rods. Sizes would be in order of say 0.100 inch and i would need a fair range around this.

regards

Chris

[Chris TickTockParticipant @christicktock]

[JasonBModerator @jasonb]

If holding the rod at right angles to the turned length then "pin gauges" would be the UK term where the diameter of the rod is used as the Gauge. These tend to come in sets covering a range of size sfrom 1mm to 6mm or the imperial equivalent and can set you back several hundread pounds.

Not seen any where the rods come in different lengths

Most in teh UK would use gauge blocks which are as they say blocks not rods, you can get these in sets to make up 0.001" or 0.01mm increments again several 100s for new

Maybe ask your expert for a make or link to a supplier, even if US based it would enable you and us to see what you are looking.

Edited By JasonB on 05/09/2019 10:33:50

[Anonymous]

Can't say I've ever come across length gauges for comparison purposes. Apart from anything else how are you going to compare the lengths to check the size? As JasonB says pin gauges are readily available, but expensive; the diameters are accurate, length isn't. They exist because measuring the diameter of small holes is difficult. Length is easy, use a micrometer. The only common length rods I've seen are for checking micrometers, and they only come in a very limited range and have rounded ends.

Full sets of gauge blocks allow setting in 0.0001" and 0.001mm increments.

Andrew

[Chris TickTockParticipant @christicktock]

Thanks Andrew and Jason yes pin gauges is the UK equivalent and yes they can be very expensive. If I am just using the known diameter to match / gauge what I am cutting on a micro item would machining my own variants from say 3 inch EN1A leaded or Silver steel suffice?

Regards

chris

[Howard LewisParticipant @howardlewis46836]

If you are checking lengths, then the most accurate way is as already suggested, Slip gauges (Jo Blocks etc )

BUT DO use the protective slips at each end of the gauge block,

Would a depth mic not do the job, as a simpler and cheaper alternative??

Howard

confounded emojis!

Edited By Howard Lewis on 05/09/2019 11:13:20

[Chris TickTockParticipant @christicktock]

Posted by Howard Lewis on 05/09/2019 11:12:38:

If you are checking lengths, then the most accurate way is as already suggested, Slip gauges (Jo Blocks etc )

BUT DO use the protective slips at each end of the gauge block,

Would a depth mic not do the job, as a simpler and cheaper alternative??

Howard

confounded emojis!

Edited By Howard Lewis on 05/09/2019 11:13:20

I'll look up slip gauges but I suspect they will for some reason not be approriate…but let me look first Howard

Chris

[JasonBModerator @jasonb]

As Andrew says a depth micrometer would be better for accurately measuring length rather than eye or finger nail comparing a round item against a length.

[Ian PParticipant @ianp]

Posted by Chris TickTock on 05/09/2019 10:18:40:

Hi guys please forgive me for as I get a lot of help / advice from our US friends sometimes the different jargon gets confused. What I am looking for is precision ground small round rods to use to hold against micro items being machined to assess whether it is the right length. Yes there are many alternatives to measuring micro items but i like the sound of this method and wish to source suitable gauge rods. Sizes would be in order of say 0.100 inch and i would need a fair range around this.

regards

Chris

If slip gauges are not appropriate I am now really confused as to what you are trying to measure.

I say measure, but you say you want to 'hold the round rod against the part being machined'. Holding a gauge of any sort against the part does not seem an accurate way to measure. (Its all relative really as steel rules, magnifying glasses and good eyesight can produce accurate parts)

One simple question, do you want to measure length or diameter?

Ian P

[JasonBModerator @jasonb]

Are you holding the dia of the rod against a finished face and touching the tool against the rod to set how far it is from the face eg to gauge the position of a cut? Gauging by eye, gauging by feel or something else. If the first option the gauge blocks will be better than rods.

[Chris TickTockParticipant @christicktock]

 

OK this picture might help. For diameters I will use a micrometer. For lengths holding a pin gauge under magnification against the cut as in photo. Now back to the question can I make a collection of various diameters on my lathe that will suffice and if so EN1A leaded or Silver Steel? Remember this is micro machining.

Regards

Chris

Edited By Chris TickTock on 05/09/2019 11:50:20

[Ian PParticipant @ianp]

I'm sure others will know better ways of measuring distances like you show, but a steel rule will be inherently better than eyeballing the edge of a cylindrical gauge.

Other than that why not just use the indexing on the lathe feedscrew dial (or a DRO or DTI) and make the part the correct length?

Ian P

[Chris TickTockParticipant @christicktock]

As a follow up question gape pins need calibration is this essential or more dependant upon actual use?

Chris

[JasonBModerator @jasonb]

Gauge blocks would do what you show and easier to compare the flat side with the faced shoulder and they will be more accurate than home made.

If you want to turn your own then EN1A will be fine as they are unlikely to get enough use to wear. or need callibration.

I assume Gape pins are the same as pin gauges

 

Edited By JasonB on 05/09/2019 12:19:38

[Chris TickTockParticipant @christicktock]

Posted by Ian P on 05/09/2019 11:59:58:

I'm sure others will know better ways of measuring distances like you show, but a steel rule will be inherently better than eyeballing the edge of a cylindrical gauge.

Other than that why not just use the indexing on the lathe feedscrew dial (or a DRO or DTI) and make the part the correct length?

Ian P

Thanks Ian, look on a forum you get many opinions and that's good right and proper. The various methods of measuring are many and I have looked into them and arrived for better or worse at the point that I will be using the micrometer for diameter and the gauge pins for length. Every method that can be used can introduce errors especially when measuring so small stuff. As I agree there are viable alternatives but I am sticking for the present with my advisors advice.

Chris

[Chris TickTockParticipant @christicktock]

Posted by JasonB on 05/09/2019 12:13:56:

Gauge blocks would do what you show and easier to compare the flat side with the faced shoulder and they will be more accurate than home made.

If you want to turn your own then EN1A will be fine as they are unlikely to get enough use to wear. or need callibration.

I assupe Gape pins are the same a spin gauges

Thanks Jason …well will be gaping at them!. I agree square faces might be better can't see set with imperial range of about 200 up to 0.250 inch

Chris

[JasonBModerator @jasonb]

Another option to save you making a load of pins is to use the shanks of drill bits, just check the actual shank with your micrometer as they may be 0.1mm below nominal size so just use one that measures what you want. I often do this to gauge the width and depth of small grooves.

With Gauge blocks you tend to group then together known as "Wringing" so for say 0.221" you would combine 3 blocks 0.200 + 0.020 + 0.001

Edited By JasonB on 05/09/2019 12:25:03

[Tony Pratt 1Participant @tonypratt1]

Yes you can turn the various required diameter pins yourself, silver steel/mild steel will be ok for these or just use the lead screw hand wheel if you have one to achieve the required step distance.

Tony

[Chris TickTockParticipant @christicktock]

Posted by JasonB on 05/09/2019 12:23:01:

Another option to save you making a load of pins is to use the shanks of drill bits, just check the actual shank with your micrometer as they may be 0.1mm below nominal size so just use one that measures what you want. I often do this to gauge the width and depth of small grooves.

With Gauge blocks you tend to group then together known as "Wringing" so for say 0.221" you would combine 3 blocks 0.200 + 0.020 + 0.001

Edited By JasonB on 05/09/2019 12:25:03

Thanks Jason OK I am learning stuff, I think at this point I will get back to my advisor and ask why he isn't using gauge blocks with square ends?

Regards

Chris

[HOWARDTParticipant @howardt]

How accurate are you hoping to get. It seems that you are comparing rather than measuring, so why not use slips under a microscope or some other optical comparator. I am sure there is someone here who worked in an inspection department that could make a recommendation.

[Anonymous]

We need to go back to basics. How accurate do the lengths need to be? That's not the same as how accurate you want them to be.

To use a comparative method the reference item needs to have a sharp edge. All my gauge blocks have slightly rounded edges. Gauge pins might be better but not perfect. A sharp edge may damage the work when using them for the intended purpose of checking hole size.

I suspect the parts are too small for depth micrometers to be practical. I'd just use the dial on the lathe top slide, should be good to a thou or so.

These people sell HSS and carbide drill blanks:

**LINK**

To make a 0.221" stack I'd use 0.1" and 0.121" blocks; my set doesn't contain 0.02" or 0.001" blocks.

Andrew

[peak4Participant @peak4]

Maybe use your favourite search engine on the term "drill blank set", essentially drills but before the flutes or cutting edges are machined. Often more expensive than a set of drill, but drill sets are often made with undersized shanks

For Example, though there are other suppliers of course

Bill

Edited By peak4 on 05/09/2019 13:00:02

[JasonBModerator @jasonb]

As has been said you can use the topslide handwheel or a DRO if you have one.

Lets say the photo is a 0.221" dia rod. I would touch my tool against the lefthand shoulder and set the handwheel dial to 21. Then turn the smaller diameter stopping when the handwheel was on zero and just over two full turns away.

Alternative is to hold the rod or block against the left hand shoulder and bring the tool up to touch the rod where you would then set dial to zero, you then turn the smaller dia stopping at zero. You can also use a finished part as the gauge if you want one to slip onto the spigot and both ends flush.

Both these methods would be better than comparing by eye or feel.

I don't have gauge blocks so my suggested sizes may not be what comes in a set.

Edited By JasonB on 05/09/2019 13:22:42

[Chris TickTockParticipant @christicktock]

Posted by Andrew Johnston on 05/09/2019 12:54:32:

We need to go back to basics. How accurate do the lengths need to be? That's not the same as how accurate you want them to be.

To use a comparative method the reference item needs to have a sharp edge. All my gauge blocks have slightly rounded edges. Gauge pins might be better but not perfect. A sharp edge may damage the work when using them for the intended purpose of checking hole size.

I suspect the parts are too small for depth micrometers to be practical. I'd just use the dial on the lathe top slide, should be good to a thou or so.

These people sell HSS and carbide drill blanks:

**LINK**

To make a 0.221" stack I'd use 0.1" and 0.121" blocks; my set doesn't contain 0.02" or 0.001" blocks.

Andrew

Thanks Andrew, from what I am so far minded;

Either i should by a used set (likely) of gauge pins or make my own (not so likely). Drill blanks would be expensive to make a set and machining them tricky although possible using ceramic cutters. I appreciate you mentioning your gauge blocks are slightly rounded as this also is a factor. Regarding accuracy of lengths at this stage I am aware some dimensions are more critical than others and this will be refined as I get bearer to actually attempting to machine one.

Regards

chris

[Chris TickTockParticipant @christicktock]

Posted by JasonB on 05/09/2019 13:21:33:

As has been said you can use the topslide handwheel or a DRO if you have one.

Lets say the photo is a 0.221" dia rod. I would touch my tool against the lefthand shoulder and set the handwheel dial to 21. Then turn the smaller diameter stopping when the handwheel was on zero and just over two full turns away.

Alternative is to hold the rod or block against the left hand shoulder and bring the tool up to touch the rod where you would then set dial to zero, you then turn the smaller dia stopping at zero. You can also use a finished part as the gauge if you want one to slip onto the spigot and both ends flush.

Both these methods would be better than comparing by eye or feel.

Thanks Jason I have noted your method. It would have to be argued why is my advisor not just using the hand wheels on the lathe as you suggest? I will ask him and have every confidence there is a reason as he is a renowned expert on the Sherline lathe and micro machining. Unfortunately I get bits and pieces fed to me then think on it and challenge why. To date apart from disagreeing on him using WD40 as a cpolant for I think brass he said I have ended up always agreeing with him in the end. WD40 will gum up the lathe if your not careful is my thinking same as on clocks, but if your careful even that would be fine.

Regards

Chris

I don't have gauge blocks so my suggested sizes may not be what comes in a set.

Edited By JasonB on 05/09/2019 13:22:42

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