Bridgeport Mill Tachometer

[YYCHM]

I don’t use any pull-up resistors, just the I2C board connected to the LCD pins.

Did you change the sketch LCD address to match the I2C address scan from the ardumotive sketch?

Any chance you have a cold solder joint in the LCD pins? (I’ve used the LCDs and address info on dozens of different designs)

I've tried addresses 0x27 and 0x3F with no luck. The I2C LCD came from Simcoe preassembled so if there is a cold joint it came that way. I traced pin to pin continuity to eliminate bad wiring with an ohm meter as well.

UPDATE: I got her going. Changed the lcd.begin(16,2); statement back to lcd.init(); which wouldn't compile before for some reason and away she went. Had to add a lcd.backlight(); statement otherwise it was very hard to read.

 

[YYCHM]

Finally bundled into an enclosure....



The processor shield and battery holder are being held down with 2 sided tape, will see how long that lasts LOL.

The LCD I ended up hot gluing to the enclosure lid.



Nice and compact once it's sealed up. I'll hot glue some magnets to the back of the enclosure and stick it to the belt cover where the IR sensor needs to feed in to clock the spindle pulley.

And the readings match my hand held Tach.....

 

[whydontu]

Cool! Can you parasite 9 volt DC from something nearby?

 

[YYCHM]

Cool! Can you parasite 9 volt DC from something nearby?

Nothing that I care to break into to find. A 9V battery should last a long time should it not?

 

[Susquatch]

Nothing that I care to break into to find. A 9V battery should last a long time should it not?

Very nice project @YYCHM ! I'm super jealous.

I soldered up the headers on one of my Nanos yesterday. It wasn't as easy as I remembered from years gone by. I've had several surgeries on my right eye and then a cataract lens replacement on it too. Looks like my left eye is doing the same thing now - I really can't see out of it any more. Covid has delayed the required surgery. Soldering with just one eye is a challenge because it's very hard to gauge the distance. I kept missing the joint with the tiny solder wire. Missing with the solder wire placement also bridged a few pins that had to be fixed. I guess I need to get on with fixing that eye. Anyway, I don't even know if I got everything right at the end.

@whydontu - do you know of a program download specifically designed to test the function of each pin once installed on the breakout board?

I'm no fan of 9v batteries. Those snap clips they use to attach them are a Royal PIA and they always break after a while. I don't mind the compartment style compression attachment though.

While I'm on the subject of batteries, here is a tip for everyone. If you need alkaline batteries, never buy anything but Eveready Energizer Max alkalines. They are the ones with the red nike swoosh on them. They are the only batteries that have never leaked on me. They are designed and marketed with that feature. I hate finding a perfectly good flashlight or whatever ruined by dead alkalines that leaked. The Energizer Max batteries don't do that. Duracells are the absolute worst.

There is nothing wrong with a 9v battery supply, but if I needed batteries, I'd prolly use a pack of AAs instead. I am planning a separate power supply for my stuff. Prolly running off the input supply for my VFD or maybe a block running on a separate 115V.

 

[YYCHM]

Got her finished up today.....



One thing I discovered is that this IR sensor is more of a proximity switch than anything else. It will trigger if any object is close enough no matter what color it is. As a result mounting the sensor with the correct distance from the spindle pulley was a bit fiddley. Here you can see the white spot I painted on the bottom pulley sheave.



Here is the enclosure stuck to the bottom half of the belt cover with magnets.

I'm pretty happy with this arrangement as I only had to drill two holes in the belt cover rather than figure out how to mount a magnet on the spindle pulley for a Hall Effect sensor. Plus I couldn't find any Hall Effect sensors that were self contained like this.

I'll have to have a serious look at the algorithm used to compute RPM as there are some aspects of the output I don't care for.

Now back to the RT-Chuck adapter plate project the postman so rudely interrupted.

 

[whydontu]

Got her finished up today.....

View attachment 17810

One thing I discovered is that this IR sensor is more of a proximity switch than anything else. It will trigger if any object is close enough no matter what color it is. As a result mounting the sensor with the correct distance from the spindle pulley was a bit fiddley. Here you can see the white spot I painted on the bottom pulley sheave.

View attachment 17811

Here is the enclosure stuck to the bottom half of the belt cover with magnets.

I'm pretty happy with this arrangement as I only had to drill two holes in the belt cover rather than figure out how to mount a magnet on the spindle pulley for a Hall Effect sensor. Plus I couldn't find any Hall Effect sensors that were self contained like this.

I'll have to have a serious look at the algorithm used to compute RPM as there are some aspects of the output I don't care for.

Now back to the RT-Chuck adapter plate project the postman so rudely interrupted.

if you can, put a small dark shroud around the sensor. My first try was jittery if the shop was brightened by light coming in from my shop window. Putting in a shroud helped a lot. Jitter wasn‘t noticeable when I built the tach in November (monsoon season in Vancouver)

 

[YYCHM]

if you can, put a small dark shroud around the sensor. My first try was jittery if the shop was brightened by light coming in from my shop window. Putting in a shroud helped a lot. Jitter wasn‘t noticeable when I built the tach in November (monsoon season in Vancouver)

The sensor is under the belt cover, it should be nice and dark in there. I'm not seeing any jittery readings. The LCD refresh rate is noticeable and a little annoying, but maybe it's just me. I'm not liking the fact that it doesn't measure 0 RPM when I stop the mill but I'm pretty sure that's just a given for the algorithm being used and why you labeled it Spindle LAST. From 1200 RPM to stop the residual reading is 170 RPM.

 

[whydontu]

I try to avoid creeping featuritis. The simplest solution would be to add a bit of code to clear the display if there’s no sensor activity after 5 seconds.

The code refreshes every 500 ms, I haven’t tried tweaking the refresh vs the sensor timing, but I’m sure it could be modified.

 

[YYCHM]

I try to avoid creeping featuritis. The simplest solution would be to add a bit of code to clear the display if there’s no sensor activity after 5 seconds.

The code refreshes every 500 ms, I haven’t tried tweaking the refresh vs the sensor timing, but I’m sure it could be modified.

Ah yes.... Feature Creep.... I know it well. Was the Bain of my existence when I was RT SCADA programming

 

[YYCHM]

Ends up the the magnets I glued to the back of the Tach weren't strong enough. My Sunday milling session ended with me holding the Tach with one hand and cranking with the other LOL......




Today, I added more magnets and moved her off to the side for more metal contact. Time will tell if she stays put

 

[whydontu]

suggestion: go find some dead computer hard drives. Killer magnets, usually flat, semi-circular poles, with backing plates and mounting holes. I use them all over my shop. Goofiest application I have: the tail stock quill on the Busy Bee B2227 lathe retracts completely into the barrel, so there’s no way to attach a dial indicator. Big hard drive magnet, aluminum bar bolted to the magnet, magnet stuck to the quill, dial indicator plunger against the magnet. (yes, the plunger is crooked, I just set it up quickly to take the photos)

How to get the neodymium magnets out of the hard drive - Magnets By HSMAG

Hard Drive Magnets – Strong and Fun Hard drive magnets can be heaps of fun. I take them out of my old hard drives and distribute them to my brothers. They can be useful for holding things together and are fun to fiddle with. They can be used to fix the book that was open […]

www.hsmagnets.com

 

[YYCHM]

LOL.... I ditched something like 15 old HDs this summer in a cleaning frenzy. The wife keeps giving me the gears about being a pack rat

 

[Susquatch]

LOL.... I ditched something like 15 old HDs this summer in a cleaning frenzy. The wife keeps giving me the gears about being a pack rat

I bet they can be had at any computer store as broken scrap.

But you can also buy neobium magnets in bulk on amazon in different sizes and attachment styles.

 

[YYCHM]

I bet they can be had at any computer store as broken scrap.

Ya, I doubt that, they take their recycling quite seriously. I got chased out of a Staples store 10 years ago for tying to liberate a power supply from the computer recycling bin LOL.....

 

[Susquatch]

Ya, I doubt that, they take their recycling quite seriously. I got chased out of a Staples store 10 years ago for tying to liberate a power supply from the computer recycling bin LOL.....

Wish I had been there to see that!

Better yet, we could have made a great team. Two old guys stealing junk from the garbage. I could have distracted them by making a scene about no toilet paper in the paper aisle while you went through their garbage.

 

[whydontu]

Best I ever did was use the hoist on the back of my pickup to fish a gas reel lawnmower out of a skip at the Vancouver landfill. Site attendant just shook his head and walked away without a word.

 

[YYCHM]

Here's one for you guys (@CalgaryPT will appreciate this as well) LOL.

CO calls me and tells me the Regiment is refreshing their IMP supply (He knows I like to use them for my mountain sheep hunting trips). I beetled down to HQ and sure as heck there were stacks and stacks of unexpired IMPs beside the dumpster. Got the van half loaded when the Regimental QM stepped out the back door for a smoke. Oh.... Oh.... That was the end of that... drove away with nothing LOL...

 

[DPittman]

Here's one for you guys (@CalgaryPT will appreciate this as well) LOL.

CO calls me and tells me the Regiment is refreshing their IMP supply (He knows I like to use them for my mountain sheep hunting trips). I beetled down to HQ and sure as heck there were stacks and stacks of unexpired IMPs beside the dumpster. Got the van half loaded when the Regimental QM stepped out the back door for a smoke. Oh.... Oh.... That was the end of that... drove away with nothing LOL...

Bummer!

 

[Tom O]

Pms hobbies has a good supply of magnets