Thread: Connection Suggestion - A Centring Scope Wiring Question

Stu,

Where did this scale come from? https://www.woodworkforums.com/162505...ml#post1581285

Bob.

Hi BT,

Thats a microscrope test slide.
calibration slide | eBay

Its one like this
0 01mm Microscope Stage Micrometer Calibration Slide | eBay
though they have doubled in price

I think I'd spend the extra $4 on this one
Calibration Slide 0 01mm Microscope Stage Micrometer With 4 Reticle | eBay

I've no idea how accurate they are, but on a sample of one they seem pretty damn good to me. Been a while but I used it to check the optical comparator, as you can see its spot on to my rule at 50X *. Thats close enough for me 99.9999% of the time. I can fire up the comparator with the stage and check it against that if you like?(though I'm not so sure that would be any more accurate. The mics are "only" 0.005mm so thats 0.25mm on the screen...... so a vernier caliper on the screen would be better. though you have added an extra source of error.

Stuart

*Ok I think I did check it with a calipier

OK, I've hit the buy it now button on the $16.90 slide. I can use it for checking the alignment on the scope with the little 0.07mm dot.

Thanks Stu.

BT

ps. When I acquired Peter Fou's comparator it was fitted with .0001" mics. Alan C-47 gave me a near mint, same vintage pair of .005mm micrometer heads which I now have on the device. It does seem strange that Mitutoyo didn't provide .002mm heads. They are not listed in their 1986 catalogue which features the PJ-250H comparator. They made them, but not for X-Y microstage use.

Originally Posted by Anorak Bob

A little bit further BJ.

I dropped into Altronics, a local electronic component supplier, and picked up a few 2.1 mm inline sockets along with half a dozen 3.5v bulb type LEDs ( tiny things, the bulb is the size of a match head ), a potentiometer to arrive at a suitable resistance and a selection of resistors to chose from when that resistance is established.

Here's the thing. My knowledge of electronics is close to zero, I did tinker with valve radios and crystal sets when I was about 13 but that interest sort of fizzed out. The young bloke who I dealt with at Altronics could not have been more helpful or more patient. He drew me a basic diagram to get me on my way.

My first task is to install a socket in the side of the Isoma. Then I'll move onto lamp replacement.

This isn't my sole optical illumination project. I have a pair of optical micrometers that require an LED substitution. The existing bulb type lamps are pretty much non existent and I have obtained some LEDS that will do the job. It's just a matter of coming up with a suitable mount for the LEDs and a more practical power supply. This may be of interest - https://www.woodworkforums.com/170823...ml#post1648726

BT

ps. The link in the linked thread doesn't work. If you are interested you could look here - https://www.woodworkforums.com/171821...ml#post1654887

Yes Bob I am interested and will peruse those links.

As far as the led's are concerned you need this information about them:
Operating current.
Operating voltage.
Bear in mind that a led is a current driven device. You need to make sure that the current through them is limited by a ballast resistor. For most led run from about 12 - 15 volts DC only, (Not AC) 470 or 560 ohms resistor would be a reasonable value.

If you want to be precise then the formula is supply voltage minus led voltage divided by the required led current in amps gives the result in Ohms.
For instance led voltage 3, supply voltage 9, led current 0.01 amps (10 milliamps)
Therefore 9 -3 = 6 divided by 0.01 = 600 ohms.

HTH.

My wife informed me last night that she had opened an envelope addressed to me because it had sat on the kitchen table for a few days, ignored. ( I reckoned she had buried it amongst some mail addressed to my daughter). She said it contained a weird thing with a wire attached. Now, last week Stuart had asked me for a few of the Isoma's internal dimensions............

So here is the weird thing mounted and under power although only 9 volts rather than the intended 12. Pretty bright even at 9.

The fit is perfect.

Outstanding Stuart. Thank you.

Bob.

ps. I should be able to improve on the wiring.

Now that you mention this, I do recall that query from Stuart and wondered what he was up to. I did have an inkling the result might be the "weird thing". Sneaky sod.
Dean

Hi Bob,

You put it together wrong Though as I'm not sure it will fit the way I planned so maybe you haven't lol. The way it is "meant" to be doesn't give you anymore Z anyway, just more room between the workpiece and the front of the scope(which doesn't seem like it would be much of an issue anyway, so I'm solving non issues again)

Take the black thing with the opaque filter and put it in a box some where.
Fit the PCD into the scope, then the poly "crystal" then the threaded ring.
But hey.. if it works as you've put it together and you aren't having ghosting issues from stray light(or a short circuit) then its all good (You shouldn't need the opaque filter as the leds have a pretty even light, but it does have the plus that cant see the PCB)


Forgive the ugly soldering, its pretty much the first time I've messed with surface mount and I forgot I had a smaller tip until after the job was done. Its more proof of concept and to find just how much light s needed than worlds best practice. If its bright enough at 9V you likely be able to run it for a long time on a AA battery(with a DC to DC converter(they haven't shown up yet). Its only 30mA at 12V according to my meter. To bad you cant get that arbor out.


Stuart

Nice job Stuart, I'm guessing the PCB was machined on the lathe. there's always a new way of doing something.

Ray

Originally Posted by RayG

Nice job Stuart, I'm guessing the PCB was machined on the lathe. there's always a new way of doing something.

Thank you, lol Yes, lathe followed by a die grinder to cut the middle track into segments. I did think about removing the P but thought CB might confuse .

Stuart

p.s. A pleasure Bob.

Good work Stuart. Finally Bob, you can put this project to bed!

You better send it to me for final inspection…..

Simon

Originally Posted by Stustoys

Hi Bob,

You put it together wrong Though as I'm not sure it will fit the way I planned so maybe you haven't lol. The way it is "meant" to be doesn't give you anymore Z anyway, just more room between the workpiece and the front of the scope(which doesn't seem like it would be much of an issue anyway, so I'm solving non issues again)

Take the black thing with the opaque filter and put it in a box some where.
Fit the PCD into the scope, then the poly "crystal" then the threaded ring.
But hey.. if it works as you've put it together and you aren't having ghosting issues from stray light(or a short circuit) then its all good (You shouldn't need the opaque filter as the leds have a pretty even light, but it does have the plus that cant see the PCB)


Forgive the ugly soldering, its pretty much the first time I've messed with surface mount and I forgot I had a smaller tip until after the job was done. Its more proof of concept and to find just how much light s needed than worlds best practice. If its bright enough at 9V you likely be able to run it for a long time on a AA battery(with a DC to DC converter(they haven't shown up yet). Its only 30mA at 12V according to my meter. To bad you cant get that arbor out.


Stuart

Well I'll be !!! I thought it was store bought!!! I'm yet further in your debt Stu.

A few more snap shots to illustrate your intention to others. And had I opened the envelope I would have discovered the nicely cut plain cover glass.

016 (Large).JPG017 (Large).JPG018 (Large).JPG019 (Large).JPG020 (Large).JPG021 (Large).JPG023 (Large).JPG022 (Large).JPG025 (Large).JPG

The nose of the mirror tube projects too far to enable the PCB to be installed before the bronze coloured threaded sleeve. The PCB has the same O.D. as that of the sleeve which enables it to be secured by the black screw-on nose piece. For it to work as intended I will need to make a new abbreviated nose piece incorporating a means of securing the cover glass. At present the black nose piece is 17mm long, that length necessary to accommodate the E5 lamps and their mount. I should be able to trim off at least ten millimetres.

Oh, and to explain the comment regarding the removal of the arbor. Stuart suggested the installation of batteries within a new hollowed out 30 taper arbor and the fitting of a simple on off switch where the present cable entry is. I'm real nervous about tampering with the mirror tube again. Alignment of the mirror is a hit or miss affair. Hours of misses is off putting.


Again, thank you so much Stu.

Bob.

Hi Bob,
Damn, I thought the mirror tube was below that face . If you think its worth pursuing it will be easy enough for MKII to have a larger hole.
How big would the hole need to be and does the mirror tube project less than the thickness of the CB and LEDS?

Stuart

p.s. Its easy from 3000kms away to say "stick in in the vice and unscrew it". I can understand your trepidation. As with a lot of these things, the second one is a lot easier .

I'm not going to exploit your wonderful generosity Stu. I will measure the projection tomorrow and see it the Mk I can be modified to suit. If it can I reckon I could save maybe 14mm of the 17.

BT

See how it goes Bob.
If it will make it fit, cut the outside track twice, move a resistor and add a wire, you can remove the red area of the CB(those wire saw blades do a pretty good job on CB) . If it would suit the running of the figure 8 wire better, you could move all the cuts etc around 90 degree and remove the bottom section instead.

Failing that I have more LEDs in the post.

Stuart