Good to see someone else who likes information. My favourite electronic tool is the oscilloscope because it lets you see the invisible and the insanely fast!
Hi, professional machinist here, great video! Thanks for showing us the tach! I want to add one to my mill, because it's faster than the dial shows. SAFETY MESSAGE: NEVER spin up a 3 jaw scroll chuck without gripping something in the jaws! They can spin out on their own, and become DANGEROUS PROJECTILES! Cheers! 😁
It's always nice to know your speed, however like many machinists I often use my gut as well. I'm having a hard time imagining how is yours could get loose in a scroll chuck unless they were right at their limits. But I'll keep your warning in mind.
Excellent video. Have a look at that TouchDRO box. There are solder points inside that allow you to connect a tach signal. Then TouchDRO will do really fancy things like chip load calculations.
Some people have complained that the readout on their unit reads, 'LLLL'. That's normal for when there's no signal coming into the unit from the sensor. The other problem that they have and you demonstrate this that the orientation of the magnet is important. The sensor won't pick up the magnet if it's in the wrong orientation. I also mounted a unit on my mini-lathe but made a small bracket that I fit 'inside' the lathe head and glued the magnet to the shaft inside. The wiring goes through a small hole that I've chamfered so as to not wear the insulation and the wire goes into the control box
the tachometer's I used show a single zero in the absence of a signal and not the "LLLL" that you have seen. I considered mounting the sensor inside, but it just seemed like more work than was necessary. I would encourage you to put a grommet or some kind of plastic strain relief inside the hole that you chamfered - that is the more common practice for that situation.
@@GuyMarsdenMakesStuff The hole is carefully rounded (beveled) and smoothed so it will not wear at the insulation. I've been doing electrical installations all my career. Some of the bushings designed for the purpose are metal instead of plastic or rubber. They work just fine. It's the smoothed rounded edges that make them effective, not the materials they're made of. I've seen so many of the sensor installation jobs that are 'out there in the breeze so to speak' getting oil, swarth, dirt on them, getting bumped etc. In my installation, one would not not even know it's there if it were not for the readout in the control box similar to yours. I like it. I'm going to mount one at some time in the future in my bridgeport and will also mount it where it cannot be seen, or get dirty, or bumped. I honestly believe that most people mount the sensor and the magnet where it will take the least amount and time and effort. Not where it makes the most sense. 😉
@@fredflintstone8048 OK, I'll give you a pass on that hole - this time! :) Totally agree, but I wouldn't want other less experienced readers of these comments to get the wrong idea... (I'm an electrical engineer and design products, so I too know whereof I speak!)
@@GuyMarsdenMakesStuff Yes, of course, whenever a wire passes near any sharp object and there is any kind of vibration (movement) there will be wear on the insulation. One interesting thing that's happening in the automotive world is those black plastic corrugated loom jackets used to protect wires in the engine compartments and in various other places in and under the cars get brittle and vibration has been causing them to cut into wiring harnesses causing wires to short to each other and also expose the copper to the moist air causing corrosion which dissolves the copper over time turning it into green crusties. So even plastic can damage a wire's insulation. The point is that wires should not be exposed to sharp edges. Most electrical bushings are made of metals, and they're the ones that last the longest where as plastics and rubbers will off-gas over the years, dry out, and often crumble to dust leaving the wire insulation exposed to sharp sheet metal edges. I would say that the housing on my mini-lathe head is ~ 3/16 - 1/4" thick. I drilled it a little larger than the wire and then chamfered and filed smooth a nice rounded entrance and exit to the passage with no sharp edges. Yes, I knew what I was doing and why.
I do not feel bad that I put a tach on my little wood lathe even though it has stepped pulleys now that I see you even did it on your drill press. Nice to know that I have it in the right speed for turning things since you cannot see the pulleys. Have it on my mill and metal lathe as well since more critical for me to know speeds. Nice video.
Good job! 👍👍 I considered putting a tachometer on my lathe, but I gauge the speed by feel, and never had to do anything at a very specific speed I needed to know with precision. Maybe I'll install one someday simply for the geek factor. 😊
It's fun and relatively easy to install them for someone who has basic electronic skills. And it just appeals to The geek in me to have a tachometer on everything.
@@GuyMarsdenMakesStuff Yeah, i am not that electronic guy, but with your explanation, i can not fail 😃 and i just want to know, when the chips are flying at its best...every time
If you're skilled enough with AC wiring, you can pull two extra AC wires from the control box after the main power switch. Then use that to connect to a two-prong AC socket that you plug the wall power module into that powers the tachometer. But be careful!
Sure, but counters are different from tachometers. Tachometers count turns per second whereas counters simply just increment. If you research you will find electronic counters readily available.
mr guy. just did an excellent install on that RPM dohicky on my HF mill and powered it up which seems to be functioning however I keep getting erratic readings, meaning it wont hold a steady setting , anything to that? >>>>>>BTW I followed instructions to the T
I bought one for automotive use but in it's description it states 'Switch', as in turning something On or Off, and that's where I'm stuck, because that's what I bought it for, to 'Switch' something on and off. Searches have turned up nothing. Would you have any insight on how to wire it to 'Switch' something On/Off?
I'm confused. Tachometers display speed by reading a magnet attached to something spinning. There is no switching involved. What do you need to switch and why?
@@GuyMarsdenMakesStuff I need to 'switch' the 'Torque-Converter LockUp' that I installed. I need it to automatically power at around 2,000rpm (or 45mph) and I wanted to use the 'Tachometer' to the CV joint closest to the Transmission (for many reasons). I am already tired of Manually switching it on and off.
@garrykellogg3215 okay, that is actually a thorny problem with no off the shelf solution that I can think of. I happen to be an electrical engineer and could build you custom electronics for that but it would be expensive.
@@GuyMarsdenMakesStuff I was thinking of a Shift Light, but that's momentary. Also the Window Switch (used for NoS) was a thought. For I am not a rich man.
@@garrykellogg3215 I'm not an automotive guy, so you're using terms unfamiliar to me. All I can say is that I'm unfamiliar with an off the shelf solution.
It depends on the strength of the magnet, but ideally less than a quarter inch, and you have to have the magnet facing the right way, so test it before securing it.
It seems that mounting the pick-up to a random stepped pulley might not give as accurite of a reading of the actual spindle speed. Have you ever followed-up on an installation's accuracy with a hand-held RPM detector or verified with your drill press, (or lathe) RPM settings with the LED tachometer? Thinking of purchasing one of these. Great video!!
There's nothing random about the pulley that I mounted the magnet to. It's directly connected to the spindle. And yes, I have confirmed the accuracy of these devices with a separate laser tachometer. Thes little units are surprisingly accurate!
The magnet is attached to the step-pulley that is attached directly to the spindle. The RPM varies depending on which step the belt is on but that pulley is on the spindle shaft.
Your question references in terms of linear speed, which involves the diameter. The pulley groove that is used does change the RPM, but all parts of the pulley travel at the same RPM regardless of which groove is in use, which is why the location of the magnet and pickup does not matter.
