Laser Tachometer

[The Merry MillerParticipant @themerrymiller]

[The Merry MillerParticipant @themerrymiller]

Morning all,

Has any member purchased a tacho similar to the one in the image below (from e-bay I might add).

If so, I'd appreciate comments on it positive or otherwise.

Len. P.

[Les Jones 1Participant @lesjones1]

Hi Len,
I have a similar tacho to the one in your picture. Mine has an attachment that clips over the end so the spindle that sticks out of it can be held against the shaft being tested. Mine gives accurate readings both optically and when used with the attachment. I think I bought mine from CPC a few years ago. Mine looks the same as Ebay item number 170657996588 or CPC item IN02507 I think I paid about £20.00 for it. ( Not the £41.95 that CPC have it for at the moment.) I suspect all of these devices are the same basic design.

Les.

[The Merry MillerParticipant @themerrymiller]

Hi Les,

Was your tacho anything like the 2 in 1 version seen below. (on e-bay for about £14.50)

Len. P.

[Les Jones 1Participant @lesjones1]

Hi Len,
It is similar to the one in your picture but closer to the one I mentioned on Ebay and on CPC's website. This is one of the pictures from the Ebay advert.

Les.

[Keith LongParticipant @keithlong89920]

Hi Len

I bought one of the units as in your original post – it cost (from memory) £8.50 INCLUDING postage from Hong Kong!

It works just fine for the use I have for it, checking lathe and motor speeds. I came with some sticky refelective strip to produce the marker pulse, but I've found there is usually enough contrast somewhere on the rotating bit that you don't need to bother. A dab of "snopake", white or black marker pen on a shiny shaft usually works just as well.

I usually just point it at a flourescent tube as a quick calibration check and if I get a reading of 6000rpm+/- a bit I'm happy, as generally I'm not looking for measuring speeds to high accruracy.

One point to watch is that there is no on/off switch on mine so the battery drains all the time, albeit at low level, so if you plan to use it infrequently it would pay to take the battery out for storage.

Mine does exactly what I wanted it for, at a LOT less than I could build a unit for in terms of time and effort. Very satisfied.

Keith

[The Merry MillerParticipant @themerrymiller]

Thanks for your input Keith,

Les, does your Tacho have an on-off switch?

Len. P.

[Les Jones 1Participant @lesjones1]

Hi Len,
There is no on/off switch on my tacho but there is a button to press when you want to take a reading. I have measured the current when the button is not pressed. It is about 150 micro amps so it would discharge the batteries over a period of time. It is worth removing the batteries when it is not in use as Keith suggests.

Les.

[Adam HarrisParticipant @adamharris13683]

So Len.P. did you buy one of those cheapo DT-2234C laser tachometers offered on ebay today around £9, and are you also as happy as Les with it? I wonder if it is a waste of time  because the cheapest today on CPCFarnell is £37….Any body else have a cheap type to recommend?

Edited By Adam Harris on 02/05/2019 18:49:43

[JasonBModerator @jasonb]

Len passed away a year or so ago.

I have one of the tachos and it works OK for me on the odd IC engine or mill spindle.

Edited By JasonB on 02/05/2019 18:54:43

[Adam HarrisParticipant @adamharris13683]

Jason sorry to hear that. I just want out of interest to check my lathe spindles and milling spindle 0rpm – 3000rpm. Should I buy one of these DT-2234C tachos?

[Adam HarrisParticipant @adamharris13683]

Great video! So it works fine.I will take the plunge. Thanks

[JasonBModerator @jasonb]

Yes it will work for that, I've use dit a few times on the mill and to check the built in tacho on the lathe. It comes with some strips of reflective tape which may be needed depending on what surface you shine it on.

Though for the same sort of outlay you can get the little tachos with proximity sensors and fit one of those which will give you a read out all the time. I have one on my mill now. This sort of thing

Edited By JasonB on 02/05/2019 19:03:22

[Adam HarrisParticipant @adamharris13683]

Thanks. And thanks for the nice video!

[Tony Pratt 1Participant @tonypratt1]

Posted by JasonB on 02/05/2019 19:01:13:

Though for the same sort of outlay you can get the little tachos with proximity sensors and fit one of those which will give you a read out all the time. I have one on my mill now. This sort of thing

Hi,

Has anyone got an idiots guide to wiring up the 'little tachos' as linked above? I have the display, ribbon cable & sensor, thanks in advance.

Tony

[JasonBModerator @jasonb]

You can also just read the numbers on it but a magnifying glass will help

[Adam HarrisParticipant @adamharris13683]

And do you have to fix the little magnet to the spindle ? How far must the proximity switch/sensor be to the magnet?

Edited By Adam Harris on 02/05/2019 19:46:01

[Adam HarrisParticipant @adamharris13683]

I've just bought the DT-2234C but might also try one those permanent installations

[JasonBModerator @jasonb]

I just cleaned the spindle with acetone and then stuck the magnet on with Araldite, check magnet is the right way round first. Gap can be upto about 10mm but less is better.

[Tony Pratt 1Participant @tonypratt1]

Jason B,

Thanks for the excellent 'guide'!!!

Tony

[Adam HarrisParticipant @adamharris13683]

I think it would be a useful tool when I am running the 3-phase 50 hz 400v motor (sadly non-dual voltage), with a 230v inverter setting inverter parameters pretending the motor is 230v 29hz – full torque up to 29hz but moving to higher frequency the torque declines such that one might not be able to reach the intended higher spindle speeds. This would be great for seeing real speed in such circumstances.

Edited By Adam Harris on 02/05/2019 20:27:20

[fishy-steveParticipant @fishy-steve]

Posted by Adam Harris on 02/05/2019 19:47:36:

I've just bought the DT-2234C but might also try one those permanent installations

Hi Adam,

Wish I had seen your post earlier. I purchased the same tacho that is in the picture of the first post.

It didn't work. It was a piece of junk. Hope you have more luck with yours.

Steve.

[Adam HarrisParticipant @adamharris13683]

Thanks Steve, a bit late but I shall remain hopeful as JasonB demonstrates using the exact same model too. Well I can suffer £9 loss but actually ebay pretty good at getting money back for buyers when item faulty. I will let you know as soon as it arrives next week

[Harry WilkesParticipant @harrywilkes58467]

Posted by JasonB on 02/05/2019 19:58:00:

I just cleaned the spindle with acetone and then stuck the magnet on with Araldite, check magnet is the right way round first. Gap can be upto about 10mm but less is better.

Sensor needs to see the south pole of the magnet, mines been working now for around 3 years without any problem I use a mobile phone charger to power it .

H

[Adam HarrisParticipant @adamharris13683]

Absolutely delighted with this £9 purchase on ebay (many sellers offering it). Tested on the trusty Super 7. Gizmo comes in nice little blue pouch. It comes with sticky reflective tape. Snip off a bit, stick it on the chuck, and aim the laser device at it. So on theoretical slowest belt setting of 210rpm, gizmo shows 237 rpm, and on fastest theoretical belt setting of 2105 rpm, gizmo shows 2093 rpm. Could not be more pleased! Pictures to follow…

Edited By Adam Harris on 09/05/2019 17:35:57

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