Finished another tool

[DICKEYBIRD]

Some time back I built a manual depth gauge per Marv Klotz's method. I've been having trouble measuring the results accurately so I made a fixture for it this morning.

Before ya'll attack me for wasting precious stock, I have to tell you I made it big for a couple reasons. One, I recently acquired a pile of aluminum off-cuts from a friend for almost nothing. Two, I've never done any "pocketing" and was wanting to try it and lastly my new carbide tipped cutoff saw was itching to attack a big chunk of stock.

To use it, I attach a flat tip to the D.I. shaft, clamp it in the fixture with a little bit protruding out the far end; position the tip flush with the face of the fixture with a parallel and zero the dial. When the gauge is pressed in and held square against the face, it gives a direct and accurate reading.

Here's some pics of the little gauge. Ain't it cute? Thanks Marv!

 

[mklotz]

Nice job. I'm flattered to see someone actually making something I've published.

Looks like a 2" indicator which would set the range you can measure. For longer lengths, you could make up some sleeves in aliquot sizes to go between the depth gauge and your DI fixture. For instance, a 1" sleeve would expand the range to 3".

 

[DICKEYBIRD]

Thanks Marv, I never even thought about needing to measure beyond 2" but now I know how to do it when the time comes.

Sheesh, I thought for a nanosecond there you'd made a rare typo with the word "aliquot" but with me being unwashed and uneducated I figured I better go ask uncle Google before making any rash judgements. Glad I did, I learned a new word!

 

[mklotz]

Using aliquot sizes raises the mathematically interesting question of WHICH aliquot sizes to use.

I made some extension rods for one of my 1" DIs. These are simply 1/8" brass rods threaded 4-48 - male on one end and female on the other - so they can be attached to each other to create extensions with lengths that are multiples of one inch.

My first inclination was to make 1,2 and 3" extensions. This would allow me to combine them so as to make extension rods of 1,2,3,...6" length. But then, being a long time computer programmer, I realized that, if I made them in a binary progression (1,2,4), I could form all the lengths up to 7" for no increase in the amount of work done.

Later I applied this same idea to making weights for a small balance scale I built. Instead of the standard European money progression (1,2,5,10...) for the weights, I made them in a binary progression (1,2,4,8,16...) which gives me greater range for a smaller number of weights.

So this leads to Klotz's conjecture:

For additive units (e.g., measuring rods, weights, etc.), the maximum range of possible values for a given number of units is achieved if the units are made in binary progression.

It's offered as a conjecture because I've never made the effort to rigorously prove it, though I'm fairly sure it's generally true.

 

[Hexbasher]

hate to be a jackass (which i pride myself of being) but couldn't you just use the depth rod or step measurement on a pair of calipers (vernier, dial, digi, whatever) to measure the mini depth gage????????????

cute fixture though....should have done a 0.005 finishing cut to clean up that chatter

because i made a similar depth gage with a 1/16 drill rod (to measure depth of small threaded bolt holes, or whatever) and i use my calipers to compare...

 

[DICKEYBIRD]

hate to be a jackass (which i pride myself of being) but couldn't you just use the depth rod or step measurement on a pair of calipers (vernier, dial, digi, whatever) to measure the mini depth gage????????????

I'd been using digital calipers to measure it but as mentioned above was having difficulty getting a consistent reading due to dexterity/alignment problems. Granted, most hole measurements don't have to be THAT accurate but I do occasionally work with model aircraft engines and want to be able to measure the stroke accurately.

Could'a bought a dial or digital depth mike but the little manual gauge is small enough to get into tight places....and is CHEAP.

Chatter? That ain't chatter....I've got some other things around here that have some REAL chatter!

Besides, I was so proud of myself after making innumerable passes without making a wrong turn of a crank and leaving a big gouge somewhere that I didn't even notice the chatter. I did make a top speed, .006" final cut but still got a little chatter.

 

[deere_x475guy]

Besides, I was so proud of myself after making innumerable passes without making a wrong turn of a crank and leaving a big gouge somewhere that I didn't even notice the chatter. I did make a top speed, .006" final cut but still got a little chatter.

Amen I know that feeling. Nice job.!