Digital Tachometer Kit.(M.I.C.)

[gus]

This came in today in bits and pieces. In between breaks building the V-2 Engine,will knock up a plywood housing to hold above. The housing will serve as hand-held Tacho.
Copy Cat Gus needs some suggestion and ideas. Am told that some HMEM Members have done this Tacho. Help.

 

[canadianhorsepower]

This came in today in bits and pieces. In between breaks building the V-2 Engine,will knock up a plywood housing to hold above. The housing will serve as hand-held Tacho.
Copy Cat Gus needs some suggestion and ideas. Am told that some HMEM Members have done this Tacho. Help.

Hi gus the sensor has 3 wires
it should be written if its a PNP or
NPN different output
give me a part number and I will help you
we use them on PLC and robots a lot

cheers

 

[tornitore45]

I just ordered an RPM/SFM kit from MachTach

It display RPM but you can also dial in the diameter and it display the SFM, it also come in metric to display SMM.

Should be fun to assemble.

 

[TorontoBuilder]

I just ordered an RPM/SFM kit from MachTach

It display RPM but you can also dial in the diameter and it display the SFM, it also come in metric to display SMM.

Should be fun to assemble.

I'm trying to decide if I can make the same based on an arduino, but I'm not sure I can beat the machtach price. it's a very good value.

 

[Blogwitch]

Gus,
That is the one I talked about a few weeks ago.
The cables should have plugs on the end that can only fit one way onto the circuit card pins.
The white twin cable is for power, and I can't remember what the voltage required was, but that should be on the bit of paper that came with it or on the ebay page where you bought it from, It showed a small circuit diagram.
Anyway, all I did was to root through my junk boxes and I found a wall wart that gave the correct voltage, but they only cost a few bucks for one with selectable voltages. If you want a portable unit, then I am sure you could use a battery box giving the correct voltage output.
Connect the wall wart and cable together so that the polarity is correct going to the card and turn the wart on.
The display should then start up, and when you pass the magnet that was supplied in the kit across the front face of the sensor, it will start to show a reading, you might have to do it fairly quickly.
It is then a matter of either sticking the magnet on or embedding it into the rotating part, then mount the sensor close to where the magnet passes, job done.

John

 

[canadianhorsepower]

I'm trying to decide if I can make the same based on an arduino, but I'm not sure I can beat the machtach price. it's a very good value.

I don't think you'll be able to
you would need a counter for that

SFM = ( RPM x DIA ) / 3.82
RPM = ( SFM x 3.82 ) / DIA

 

[DJP]

I purchased an inexpensive tach that measures rotation by reflection of a laser off a piece of reflective tape. It's crude but it works and the reality is that I only needed it to measure rpm once for each pulley belt setting. The tach now sits unused so my only advice is that you should not spend too much money to measure rpm when it doesn't change.

 

[TorontoBuilder]

I don't think you'll be able to
you would need a counter for that

SFM = ( RPM x DIA ) / 3.82
RPM = ( SFM x 3.82 ) / DIA

It's technically not difficult, its trying to come in at a price less than the tachmach is sold for...

 

[TorontoBuilder]

I purchased an inexpensive tach that measures rotation by reflection of a laser off a piece of reflective tape. It's crude but it works and the reality is that I only needed it to measure rpm once for each pulley belt setting. The tach now sits unused so my only advice is that you should not spend too much money to measure rpm when it doesn't change.

Agreed. ebay has tachometers for about 12 bucks. A hall sensor is a cheap add to a arduino if you have one with an LCD keypad its all you need to for the user interface to input a workpiece diameter.... no need to use a fancy rotary encoder like tachmach does.

 

[gus]

Gus,
That is the one I talked about a few weeks ago.
The cables should have plugs on the end that can only fit one way onto the circuit card pins.
The white twin cable is for power, and I can't remember what the voltage required was, but that should be on the bit of paper that came with it or on the ebay page where you bought it from, It showed a small circuit diagram.
Anyway, all I did was to root through my junk boxes and I found a wall wart that gave the correct voltage, but they only cost a few bucks for one with selectable voltages. If you want a portable unit, then I am sure you could use a battery box giving the correct voltage output.
Connect the wall wart and cable together so that the polarity is correct going to the card and turn the wart on.
The display should then start up, and when you pass the magnet that was supplied in the kit across the front face of the sensor, it will start to show a reading, you might have to do it fairly quickly.
It is then a matter of either sticking the magnet on or embedding it into the rotating part, then mount the sensor close to where the magnet passes, job done.

John

Hi John,

Thanks for the info.
DC Voltage info is shown on the circuit next to power input socket. Gus is born loser and he bought two sets. One to make a hand held Tacho. And the other for the Howell V-2 or V-4. For now the V-2 is scary. My walk flat has no space for bigger machine tools and I make do with mini lathe and mini mill.
The V-2 just made it on the Sakai Lathe with 10 mm to spare clearing the bed slide.