dgfoster
Diamond
- Joined
- Jun 14, 2008
- Location
- Bellingham, WA
Just for for your entertainment I will recount a recent story telling how I managed to smash a piece of irreplaceable and expensive equipment loaned to me by a PM member. This is just for laughs, but I was not laughing at the time.
In the recent and still ongoing thermal expansion thread I mentioned that Carbidebob popped up and offered a loan of a Mitutoyo mini-checker and probe that he had sitting on the shelf. Though it was probably 30 yrs old it still worked just fine and certainly would improve the resolution of my measurements previously made with a Federal tenths electronic gage. The checker was very similar to this but lacked one decimal point of the mu-checker resolution:
The output "box" came with a large wall-wart power supply just like many currently in production except this transformer/rectifier probably weighed close to a pound. Just after getting it via UPS (another puckery story in itself) I tried it out and it worked great. Exciting!
After messing with it over the course of a few days and making some useful reading as reported in that thermal expansion thread, I decided I should put it in a safe place so that somehow it did not come to harm in my shop. One "safe" and little-used shelf was located about 8 feet off the floor and seemed to be an ideal safe spot. So, I got a stool and started to put the box up there with the power supply resting on top of the box. BUT, the power supply slid off the box and hit the floor with an ominous thud. I looked down and it was split wide open with the three plug spades pointing in three different directions and the PCB and transformer in clear view----not good!
I did go online and looked on ebay and Mitutoyo's website to see if I could locate a replacement. Nope. So, figuring they would completely ignore me, I contacted Mitutoyo and I was amazed to get a prompt reply. After a couple cordial emails I learned that no equivalent supply was available for this legacy device. In desperation, I asked for a pinout of the 5-conductor cable again expecting silence. But within a few minutes the tech I was conversing with had pulled up old drawings that provided the info. (Again I was amazed. Props for Mitutoyo. That sort of service is way too rare nowadays.) Now I knew I could test the existing supply and even build a new one if needed.
So, using alligator clips, I connected 110 AC to the spraddled prongs of the supply and, lo and behold, the output was perfect. Plugging it into the box made everything come to life. Yes!!!
Now all that had to be done was design an enclosure and repackage the power supply. I was determined to make the "new" power supply unquestionably better than the old brittle Bakelite one.
CAD drawing and 3-D printing to the rescue: One uncertainty in building the new box was how would I dissipate the transformer heat as the new thick box would be a much better insulator than the 1/16th-inch-thick Bakelite box. To dissipate heat, I used aluminum top and bottom plates. In use the box barely warms up at all.
Here is what I came up with:
This is the Onshape drawing. That logo was "stolen" from an image posted online of a Mit tool
And here is the 3-D Printed (PETG) box and aluminum plates. PETG is a "high impact' plastic that I am confident will withstand dropping or otherwise abusing it.
T
The feet are low-durometer rubber so they grip a surface well and the supply stays put.
My goal was to be able to say with doubt that the replacement box was better than the original.
As it turns out, Bob is allowing me long-term loan of the device. (Gard's advice in a related thread about protecting it from further damage is well-taken. Believe me!)
It's a good thing my 9-yr-old grandson was not in the shop when I dropped this thing. His mother would wonder where he learned all those "new words." ;-)
Denis
In the recent and still ongoing thermal expansion thread I mentioned that Carbidebob popped up and offered a loan of a Mitutoyo mini-checker and probe that he had sitting on the shelf. Though it was probably 30 yrs old it still worked just fine and certainly would improve the resolution of my measurements previously made with a Federal tenths electronic gage. The checker was very similar to this but lacked one decimal point of the mu-checker resolution:
The output "box" came with a large wall-wart power supply just like many currently in production except this transformer/rectifier probably weighed close to a pound. Just after getting it via UPS (another puckery story in itself) I tried it out and it worked great. Exciting!
After messing with it over the course of a few days and making some useful reading as reported in that thermal expansion thread, I decided I should put it in a safe place so that somehow it did not come to harm in my shop. One "safe" and little-used shelf was located about 8 feet off the floor and seemed to be an ideal safe spot. So, I got a stool and started to put the box up there with the power supply resting on top of the box. BUT, the power supply slid off the box and hit the floor with an ominous thud. I looked down and it was split wide open with the three plug spades pointing in three different directions and the PCB and transformer in clear view----not good!
I did go online and looked on ebay and Mitutoyo's website to see if I could locate a replacement. Nope. So, figuring they would completely ignore me, I contacted Mitutoyo and I was amazed to get a prompt reply. After a couple cordial emails I learned that no equivalent supply was available for this legacy device. In desperation, I asked for a pinout of the 5-conductor cable again expecting silence. But within a few minutes the tech I was conversing with had pulled up old drawings that provided the info. (Again I was amazed. Props for Mitutoyo. That sort of service is way too rare nowadays.) Now I knew I could test the existing supply and even build a new one if needed.
So, using alligator clips, I connected 110 AC to the spraddled prongs of the supply and, lo and behold, the output was perfect. Plugging it into the box made everything come to life. Yes!!!
Now all that had to be done was design an enclosure and repackage the power supply. I was determined to make the "new" power supply unquestionably better than the old brittle Bakelite one.
CAD drawing and 3-D printing to the rescue: One uncertainty in building the new box was how would I dissipate the transformer heat as the new thick box would be a much better insulator than the 1/16th-inch-thick Bakelite box. To dissipate heat, I used aluminum top and bottom plates. In use the box barely warms up at all.
Here is what I came up with:
This is the Onshape drawing. That logo was "stolen" from an image posted online of a Mit tool
And here is the 3-D Printed (PETG) box and aluminum plates. PETG is a "high impact' plastic that I am confident will withstand dropping or otherwise abusing it.
T
The feet are low-durometer rubber so they grip a surface well and the supply stays put.
My goal was to be able to say with doubt that the replacement box was better than the original.
As it turns out, Bob is allowing me long-term loan of the device. (Gard's advice in a related thread about protecting it from further damage is well-taken. Believe me!)
It's a good thing my 9-yr-old grandson was not in the shop when I dropped this thing. His mother would wonder where he learned all those "new words." ;-)
Denis
