Remote display sources for DRO Chinese calipers

Thirty years ago when I played AD&D, I had a half-orc cleric character called 'Phragmites the Algal' who had a two-horned helmet...

Neil

Neil,

Cheesy works for me.

Did you etch the PCBs?

Would be interested in the tacho you are doing, as I've tried the push bike speedo variety without much success, no doubt due to not putting in the correct wheel dimension.

Bought a Galaxy Tab3 and fitted a rubber BobjGear Michelin Man style case that is perfect for a workshop environment.

Installed the TouchDROHD app that will do what I want, but probably not for industrial use.

Details to follow once parts arrive for the interface box and also when I've decided what scales to use.

Geoff - Killing time before SHMBO & I head of for a mid-day Chinese meal in newly refurbished emporium.

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Geoff,

You might like this ... which I found last night

Very nicely done, thought I.

MichaelG.

Hi Geoff,
You could try my tacho design which is on my website.

Les

Hi Geoff,

I can email you AVR source code and a jpeg of the PCB, but I'm afraid I don't think I have a circuit diagram.... although it's fairly obvious from the pin assignments

Neil

A laser tacho costs <£10 here , just fix a reflective sticker to the shaft and away you go.

Only problem with that is my lack of a third hand to hold it in...

Neil

MichaelG and Les,

Thank you both for the links.

Neil,

Will take you up on your offer please, with thanks.

Robert,

Have one of those, and concur with what Neil says about holding it.

I need an on demand, brain power produced, force field type third hand, that some of the people in the scifi novel I'm reading have, and use to great effect.

Geoff - and they live for hundreds of years to boot.

Deleted the duplicated post.

Geoff - Finger problems?

Edited By OuBallie on 02/12/2013 08:08:44

This is a desperate plea ...

Does anyone have a copy of the user manual for the very early Trimos TVM300 Height Gauge? ... it has a 4 pin connector on the front panel, labelled "Sylvac System" and uses a single SR44 cell.

Note: This is the Origin of the "Chinese Scales" Species.

I have been in touch with Trimos, in Switzerland, and they have no information about this particular model. They did supply the manul for the later version [which still had Capacitative Scales, but no external connector], but I would really like to see the "official" description of that data port before I start probing. ... The instrument is working perfectly at the moment, and I could not afford to replace it if I blow anything up.

Thanks

MichaelG.

Is it so difficult for an engineer to make a simple holder for the laser tacho?

If it is, then an even cheaper and simpler solution is to use a cycle computer giving a direct RPM readout and with a wireless connection to the sensor for £2.59 here. Easily mounted even for an engineer!

I'd rather use that than spend hours constructing a tacho from basic components costing 20 times as much, when I could be making something useful, but I'm strange I know.

That's a really ingenious use of some new kind of wireless technology!

Having a length of wire between the sensor and the display seems a bit pointless to me, but the manufacturer must know what the product needs to meet its specification.

Ian P

For me, making one is just another aspect of the hobby, no different from making any other tool.

Neil

I'm not certain this tachometer would work in the first place. Two issues:

1. Bicycle wheel doesn't spin at 2000 RPM, and to hit that price point they probably didn't over-engineer the electronics... (at 400 RPM the bicycle would be traveling around 60 km/h...)

2. I'm pretty sure that magnet will add a fair bit of vibration to the spindle at higher RPMs.

Finally, I second Neil's sentiment Otherwise why would I even want to have a machine shop in my garage when most of the things I make are either "worthless" (steam engines, for example) or can be bough cheaper off eBay...

Regards

Yuriy

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Anyone ?

MichaelG.

Michael,

Do you have an oscilloscope? On X10 it should be impossible to damage anything. Compare the output waveforms with those HERE.

You don't need a Tek DSO, my ancient Hameg did the job just fine.

Neil

>edit< This is useful as well, and there is Yuriy's site as well.

Edited By Stub Mandrel on 04/12/2013 20:51:45

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Neil,

1. Yes
2. TDS200C

... But I would still like to know the Spec. of what is supposed to be there.

MichaelG.

.

Edit:

P.S.  I know what the Sylvac protocol was [please see my earlier posts] but I don't know what the electrical interface characteristics are ... and nor, apparently, does Trimos.  They have already told me that if the circuit board gets blown, there are no replacements; and "repair" would involve upgrading to the new electronics [which is almost the same price as buying a new instrument].   I feel the need to tread very carefully! ... I suspect that they deleted the connector because the interface was fragile [although no-one has actually said so].

Edited By Michael Gilligan on 04/12/2013 21:13:47

Edited By Michael Gilligan on 04/12/2013 21:16:22

Picture of TVM 300 panel, for reference

G'day. I doubt if the device actually uses a laser, that may be an optimistic description. It is a nice piece of kit for the price but the specs indicate that it may be a photo transistor/diode type of tacho similar to the one I use for my model aircraft engines.

Following this thread with interest though.

Regards from the land of the kangaroo

* Danny M *

Interesting video posted on another forum showing the ARC scales plugged into a homemade bluetooth box so the signal can be picked up on a phone or tablet and uses a free app that has all the functions of a full blown DRO