# Machtac



## royesses (Oct 28, 2020)

Henry Arnold has released to the world the Machtach schematics, source code and other information at:








						MachTach Machine Tachometer by henryarnold
					

This Thing documents the MachTach machine tachometer which was a product I used to sell. I have stopped selling MachTach kits so I am now making the design open source so that people can make their own tachometers. Please read the documentation for information on how the MachTach works, how to...




					www.thingiverse.com
				




It includes the hex file and C source code for the PIC16F690-IP microprocessor.  All files are available for free download. 
There is a download link at the top right of the page. The zip file is too large to attach here.
Got to give him a well deserved thank you for releasing it to everyone. He is a great guy and brilliant engineer.

Roy


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## hman (Oct 28, 2020)

WOW - Talk about timing!!!  I just unearthed a vintage MachTach kit and assembled it last week!  Used to subscribe to his Yahoo group, but they've all been shut down.  Tried an internet search, but no joy.  Anyway, got it built and enclosed, and it works well.  I'll have to try sending him kudos through thingvrese.  THANKS for the link!


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## royesses (Oct 28, 2020)

I burned an extra PIC16F690 yesterday as a spare just in case my machtachs get damaged. I haven't tried it yet to see if it burned ok although the burner said it passed. The copy protect bit is turned on in his code so a subsequent verify will come back with all zero's even thought the pic is properly programmed. All the other parts are easily sourced from Digikey except the printed circuit board. He is a great guy to talk to, very knowledgeable. He is a retired electrical engineer.

Roy


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## mksj (Oct 28, 2020)

Also spoke to him after he closed down making the MachTach, in my opinion one of the best tach/SFM units at the price level, but just too much competition from the Asian sellers to continuing making them. I have also used the Tachulator in subsequent builds, but the MachTach is more versatile to different machines. The Tachulator only comes with an optical reader although I have converted them over to magnetic sensors.  Asked him to burn a batch of MachTach control chips for me since I do not have a PIC programmer. If someone wants to go in on a run of the circuit boards, I would be interested in 5-10 boards. The price goes down the larger the batch.


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## Hawkeye (Oct 28, 2020)

One of my MachTachs had the voltage regulator fail recently. (Bolt the reg, U2, to the board or machine vibration could cause the legs on the reg to break.) I replaced it, but it didn't work. When I took a closer look, I saw that I had used a 7905, instead of a 7805. 

Now, I might be able to burn a new PIC and get it back on line. Thanks for posting.


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## royesses (Oct 29, 2020)

I used a TL866ii-plus programmer from Ebay. Available from a usa supplier for $56 us also from Amazon for the same price. It is usb powered and has a very long list of chips it can program. I'm not a programmer or engineer just load the .hex file choose the PIC16F device and then click program. 
Done. 

Roy


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## projectnut (Oct 29, 2020)

I had never heard of MachTach until about 5 years ago when I purchased my Sheldon lathe.  The lathe originally had a mechanical tachometer in the headstock cover.  The later model of the same machine had an electronic tachometer in the same location.  I tried for several months to find enough parts to either replace the original, or upgrade to the electronic version, but had no luck. 

In my searches I ran across MachTach and decided to give it a try.  I purchased a kit complete with the sensors, power cord, and enclosure.  I'm not all that well versed in electronics, but is was easy to follow the instructions and complete the project.  I mounted it in the location of the original tachometer and fired up the machine.  It's worked flawlessly from day one.

A couple years ago I was looking for another one for each of the milling machines.  At the time the website was down, but all the rumors were that it was temporary.  Apparently it was more than just a temporary glitch.  I never did get additional tachometers, and still use the approximate readings on the variable speed drives.

I doubt that I have the where with all to recreate what he has done even though he has made all the documentation public.

Here's a picture of my Sheldon with the MachTach tachometer installed in the location of the original mechanical one.


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## royesses (Oct 29, 2020)

If a bunch of you get together to have pc boards made the cost will be minimal, especially if the parts are ordered from Digikey in multiples of 10 or 100. Maybe $30 per machtach or so. I have 2 on my machines and one spare kit just in case. I purchased them from Tom about a year before he quit selling them. There are some china pc board houses on youtube advertising very low prices on boards. The only down side is shipping time.

Roy


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## royesses (Oct 29, 2020)

To open the PCB files use the free PCB software ExpressPCBPlus at:





						PCB CAD Software – ExpressPCB
					






					www.expresspcb.com
				




These are the people who make the boards for Henry Arnold. Henry will tell you how to do it and how to get the best price on the boards. Contact him through Thingiverse.

Roy


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## Z2V (Nov 4, 2020)

mksj said:


> Also spoke to him after he closed down making the MachTach, in my opinion one of the best tach/SFM units at the price level, but just too much competition from the Asian sellers to continuing making them. I have also used the Tachulator in subsequent builds, but the MachTach is more versatile to different machines. The Tachulator only comes with an optical reader although I have converted them over to magnetic sensors.  Asked him to burn a batch of MachTach control chips for me since I do not have a PIC programmer. If someone wants to go in on a run of the circuit boards, I would be interested in 5-10 boards. The price goes down the larger the batch.


I would be interested in a couple, myself.


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## royesses (Nov 5, 2020)

I'd be willing to buy a couple also

Roy


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## jeffkash (Nov 5, 2020)

I would be willing to aggregate PCB orders and make one big buy from ExpressPCB. I may be willing to build some for people that are not comfortable with soldering. I'm a retired EE. Let me know if you are interested. Once I get an idea of how many boards are wanted I'll get pricing.


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## jeffkash (Nov 9, 2020)

Nobody interested in a group buy of boards? I'm ready to pull the trigger for my needs.


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## Z2V (Nov 9, 2020)

I’ll take two


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## mksj (Nov 9, 2020)

I would be into getting at least 5 boards, a few more if it is at a break level to reduce the overall cost for the group.


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## pontiac428 (Nov 9, 2020)

Why deal with handheld programmers and burners at all?  This isn't 1990 anymore, what reason would anybody have for not using a microcontroller like Arduino?  With one of the mini boards, this would be a $20 project that you could customize and adjust as needed.  All you need is a USB connection to a laptop (or your Apple II's serial port if you're still on monochrome).  Not being inflammatory, just want to know why one would start down this path without looking at easy and obvious substitutions.


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## jeffkash (Nov 10, 2020)

You make some good points however not everyone can or wants to reinvent the wheel. This is a proven design with an already designed PCB, code, and manual. It is easy to duplicate and people are comfortable with it.

I've priced the PCB from ExpressPCB and they are $14 in quantities of 25. That does make for an expensive project for someone comfortable with Arduinos. The Tach is basically a pulse counter with a display. An Arduino with a serial LCD display can be put together for not much more than the $20 you quoted.

As the PIC code is now in the public domain, one could use it as a model for an Arduino sketch. Are you volunteering?


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## Papa Charlie (Nov 10, 2020)

I would be interested in one or two of PCB's


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## .LMS. (Nov 11, 2020)

If someone us thinking about selling fully assembled and tested units, I would be interested in buying one.


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## jeffkash (Nov 11, 2020)

I WAS thinking about making  fully assembled and tested units, but pontiac428 got me thinking in an alternate direction. For the price of a single component less PCB, a whole unit can be constructed from an Arduino with a LCD display. I'm currently prototyping some software to prove that it is feasible. The MachTach seems to be a simple pulse counter with a Schmidt Trigger front end. I'm trying to emulate the Schmidt Trigger in software so no external components beyond the Arduino, LCD,  connectors, power supply and case are needed. Stay tuned.


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## mksj (Nov 11, 2020)

A few things that were nice about the Machtach was the SFM, ability to use various triggers (LED, magnetic sensor and gear tooth sensor), as well as setting the number of trigger counts per revolution in one simple compact package. Otherwise one can by a cheap tach for around $12 which works just fine for most people. But I am open to alternatives if they do not need to be reprogrammed for different applications.   The Machtach in quantity I assume would be around $30-40 in parts.


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## jeffkash (Nov 11, 2020)

I don't mean to take anything away from the creator of the MachTach  but, all of the various functions are just software. I just priced the components (single quantity) on Amazon at $27 for the Arduino, power supply, LCD display, and the rotary encoder. Add an enclosure and the trigger of your choice and you are done. No programmer is required and the software necessary to get the Arduino running is free.  Configuration for SFM, RPM, counts per revolution, etc are all done via the rotary encoder and LCD. No programming skills required once someone writes the application.


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## Hawkeye (Nov 11, 2020)

When my MachTach packed it in, I built one with an Arduino Nano. Amazing how little hardware you need. It has a glitch that keeps it from displaying a steady value, but I've left that project to go on to a much bigger - a go-to drive for an 8" telescope.

There is a lot of information and hardware available for Arduino, including tutorial video courses. No time like the present to get into it.


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## ahazi (Nov 12, 2020)

jeffkash said:


> You make some good points however not everyone can or wants to reinvent the wheel. This is a proven design with an already designed PCB, code, and manual. It is easy to duplicate and people are comfortable with it.
> 
> I've priced the PCB from ExpressPCB and they are $14 in quantities of 25. That does make for an expensive project for someone comfortable with Arduinos. The Tach is basically a pulse counter with a display. An Arduino with a serial LCD display can be put together for not much more than the $20 you quoted.
> 
> As the PIC code is now in the public domain, one could use it as a model for an Arduino sketch. Are you volunteering?


Try these guys (in China) for PCB:





						PCB Prototype & PCB Fabrication Manufacturer - JLCPCB
					

China's Largest PCB Prototype Manufacturer, offers 24 hours Quick Turn PCB prototype, PCB assembly and Reliable small-batch PCB production.




					jlcpcb.com
				




You will be surprised at the price, delivery time and quality. 

I used them multiple times including assembly where they will source the parts for you at an attractive price. Might be the way to go for a group purchase.

Ariel


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## kiwi_007 (Dec 25, 2020)

Where did this get to? Did anyone collate an order?

I found out the pcb's from Express PCB is $181 for 10 and 10 MachTach IC's is $50


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## Z2V (Dec 25, 2020)

I’m in if someone moves forward with this


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## mksj (Dec 25, 2020)

I would be in for 5 if someone is interested in doing an order.


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## kiwi_007 (Dec 25, 2020)

mksj said:


> I would be in for 5 if someone is interested in doing an order.



I would've been in for some also, but just got 10 boards and IC's, I didn't really need 10 but the difference in price of the boards made it more economical to purchase 10.
With my location, New Zealand, it isn't practical for me to collate an order either.
But if either of you want to send me an email nzkiwishooter at gmail.com, I might be able to help either of you achieve something


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