Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Yes we're all here because of bitseeker so thank you due there  

@mnem: thanks for the advice on the printing. ABS is a "i might be bothered with it" thing at the moment. If I do, it's going in the kitchen with the windows open and door shut  . I fully expect to blow a week before I get something I'm happy with on each process change.

[mnementh]

<-------  Is over here casually trying to ignore the 3DP talk while my friend sends me a text that reads:  "Would you be interested in going in half on a 3D printer? I want to make some R/C parts and I know it'd come in handy for you, too."

 

Let us know which way you are facing when you stop spinning.

Let us know how you ensure that each individual manufactured item has appropriate mechanical properties to ensure it doesn't fall apart sooner than desirable. That's an issue I'm facing with my collet.

FDM is not the right tool for this job; tensile strength of even well-bonded layers is relatively poor. FDM's strength is typically more compression. SLA MIGHT hold, at least as well as OEM, but farming that out to a contractor will probably cost anywhere from $20-50 $5ish...? Holy shit that has dropped! depending on operator and material.

I strongly suspect you are right about FDM's strength, but I'll use it as a means of putting the new printer through its paces.

The SLA is solid rather than "hollow", and at £4 for 4 collets delivered (DirtyPCBs), I'm prepared to take a chance.

If that doesn't work, there's always brass or steel or aluminium for ~$17 + postage (Shapeways).

For your application, I'd mod a RC model airplane prop adapter collet and have done with it: Find one that matches the taper of the hub and the motor shaft size; this will require some trial & error at a hobby shop. The prop stud will be too short, so you'll have to drill & tap the center of the stud for a m2-m3 screw, then use a tiny fender washer over the hole in the middle of the squirrelcage. You may need to turn the prop stud down or drill the center of the squirrelcage out to match the prop stud.

Or, replace the collet with a whole grub-screw type prop adapter and drill the center of the squirrel-cage out to match the stud on the prop adapter. You may need to turn the prop stud down or drill the center of the squirrelcage out to match the prop stud.



Remember that this application is not high-precision; I literally made a serviceable replacement fan by epoxying the squirrelcage to the hub of a computer fan. Vibration was still minimal even with a good several grams out of balance.[/b][/i]

I've got a recommended prop adaptor collet on the way, but I'd like to try to avoid butchering the fan if I can.

If you can get somebody to make them in SLA for that money, obviously your best first choice. It's been a few years since I priced out anything in SLA... obviously I was wrong about THAT cost. I'm guessing in your case that  DirtyPCBs is waiving the usual "setup surcharge" that most were charging to cover slicing time & wasted resin. Maybe they're employing similar "automated batch processing" methods to their SLA tanks they use for their sheets of PCB. You're right about needing to try a threaded hole on the inside end of the plastic collet to screw a stud into.

Did you mic the shaft diameter? I could swear I remember the motor shaft being 3mm or 1/8" (3.17mm). Should not have to hack the squirrelcage if you can find a means to turn the prop stud down so it fits inside the hub, or cut the stud off and then drill & tap the collet for a center screw.

Cheers,

mnem
 

[mnementh]

No.

mnem
 

Well...FU too and the horse you rode in on.  I'm going back out to the garage and further defile the Type 114 with another coat of paint. 

I went back & deleted a post I'd already made JUST so I could fuck with you too! 

mnem
Are you feelin' tha lurrrve...? 

[tggzzz]

If you can get somebody to make them in SLA for that money, obviously your best first choice. It's been a few years since I priced out anything in SLA... obviously I was wrong about THAT cost. I'm guessing in your case that  DirtyPCBs is waiving the usual "setup surcharge" that most were charging to cover slicing time & wasted resin. Maybe they're employing similar "automated batch processing" methods to their SLA tanks they use for their sheets of PCB. You're right about needing to try a threaded hole on the inside end of the plastic collet to screw a stud into.

Why don't you take one of your existing designs and stuff it into http://dirtypcbs.com/store/print3d and see the cost? You don't need to login or have an account or any of that crap.

This Tek P6013 EHT probe handle cost £13. For an idea of scale, the length is 90mm, the thread diameter is 40.8mm with a 2mm pitch, and the flange diameter is 45mm. The thread fitted perfectly, and the only thing I might change would be to make the handle 2mm thick rather than 1mm.

Did you mic the shaft diameter? I could swear I remember the motor shaft being 3mm or 1/8" (3.17mm). Should not have to hack the squirrelcage if you can find a means to turn the prop stud down so it fits inside the hub, or cut the stud off and then drill & tap the collet for a center screw.

It was 2mm, and others have used that value.

If I need to, I'll fiddle and see what the minimum necessary change is.

[med6753]

The Type 114 is done. All cleaned up, cabinet repainted, switches deoxit'ed. Now going through a mandatory burn-in of several hours.

[xrunner]

The Type 114 is done. All cleaned up, cabinet repainted, switches deoxit'ed. Now going through a mandatory burn-in of several hours.

That paint job really looks good. 

[bitseeker]

For real! Aw, med, now you're gonna make me wanna get a 114.

[med6753]

I think one of you, or both, has a Type 106. That's next on my list but they tend to be real pricey.

[worsthorse]

Just to prove I didn't skip any posts while trying to catch up, some slide rule pron



And for the aficionados, the slide rule of astronauts money shot



Also, med the SN on my 114 is 1519.  I am going to get back to working on it today. Your signal output is clearly cleaner than what I am seeing. I don't think I should undo any of the mods (they seem to be done with Tek parts) but I am wondering...

[med6753]

Also, med the SN on my 114 is 1519.  I am going to get back to working on it today. Your signal output is clearly cleaner than what I am seeing. I don't think I should undo any of the mods (they seem to be done with Tek parts) but I am wondering...

In case you didn't notice the output is 50 ohm. So either have a 50 ohm input source or use a 50 ohm feed-thru terminator if going into 1MEG. 

[worsthorse]

For real! Aw, med, now you're gonna make me wanna get a 114.

Join the club and collect the whole set!  I mean, there's even a TV calibrator. 

How do I know? Because I have one, of course.   

Seriously, for calibrating lower frequency gear, the 114, along with the old level sine and square generators (both of which will do 100V pp, I think) are great to have around.  Even at plus fifty years old, it still works pretty damn well.

[worsthorse]

The Type 114 is done. All cleaned up, cabinet repainted, switches deoxit'ed. Now going through a mandatory burn-in of several hours.

That paint job really looks good. 

Yeah, nice work. BTW, what's the paint color and brand?  You've raised the bar and now I will need to paint a couple of these old boxes when I am done with the other work.

(I know. I know. You told me and it is somewhere in this thread and I am old and lazy and forgetful)

[worsthorse]

I think one of you, or both, has a Type 106. That's next on my list but they tend to be real pricey.

I do have a 106. I am going to put it on the bench after I finish the 114. I also have the level sine generator that goes to 100Vpp.

[med6753]

The Type 114 is done. All cleaned up, cabinet repainted, switches deoxit'ed. Now going through a mandatory burn-in of several hours.

That paint job really looks good. 

Yeah, nice work. BTW, what's the paint color and brand?  You've raised the bar and now I will need to paint a couple of these old boxes when I am done with the other work.

(I know. I know. You told me and it is somewhere in this thread and I am old and lazy and forgetful)

Krylon Colormaxx Gloss Bahama Sea

[tggzzz]

Displaying British values yet again...



HP32S 50th Anniversary Limited Edition
HP35 without suffix, of course
Sinclair Scientific
HP95LX and MSDOS3.3 machine with its RPN calculator
British Thornton AA010
... but restraining myself from showing a screenshot of the HP15 emulator running under WINE.

[bsudbrink]

I posted this in vintage computers, since that's what it's basically about:

https://www.eevblog.com/forum/vintage-computing/commoning-block/

but not many people have looked at it.  Since this is where all the cool kids (most knowledgeable) hang out,  I hope you won't mind if I put a link and take a look.

Thanks.

[mnementh]

LOL! Thanks to all of you who make the TEA house a great place to be: xrunner, Cubdriver, med6753, mnementh, bd139, Kosmic, tggzzz, Specmaster, tautech, nixiefreqq, beanflying, Neomys Sapiens, wch, and more... It certainly wouldn't have eaten the forum if I was just talking to myself.

Sometimes I want to thank you, sometimes to damn you for "wasting" so much of my life

Ditto! 

mnem
*back into the suck*

[mnementh]

The Type 114 is done. All cleaned up, cabinet repainted, switches deoxit'ed. Now going through a mandatory burn-in of several hours.      

Too shiny! *crosses arms with a scowl* Harrumph! 

mnem
Whaddayouget when you cross arms with a scowl...?

I dunno, but it can't carry Jack shit!

[tautech]

The Type 114 is done. All cleaned up, cabinet repainted, switches deoxit'ed. Now going through a mandatory burn-in of several hours.

That paint job really looks good. 

Yeah, nice work. BTW, what's the paint color and brand?  You've raised the bar and now I will need to paint a couple of these old boxes when I am done with the other work.

(I know. I know. You told me and it is somewhere in this thread and I am old and lazy and forgetful)

Krylon Colormaxx Gloss Bahama Sea

@bitseeker
Please add this to the OP as a Tek paint colour.
Med posted a pic of the spray can a few pages back and that would be good to link as the money shot.

Come to think of it Med, drop a post and that pic here too:
https://www.eevblog.com/forum/repair/vintageclassic-renovation-techniques/

[Neomys Sapiens]

Neomys levels up!

Not as far as I have previously announced, but at 314.- a steal and it left the reserves build up especially for a RLC meter completely unscathed.  Also, any accessories I will collect would be good with a PM6306 (or the Wayne-Kerr equivalent) too.
Factually, it did come so much below the expected best case that I feel tempted to complement it with the LCR45 and ESR70, and upgrade the DCA55 to a DCA75, because curve tracing is also something that is missing.
I found abroad a below-average-price IET Labs 1920, but 1MHz is a arbitrary limit. And several Stanford SR720, which were well affordable, but with their slot interface only and SRS answering no calls for spares, I remained sceptical.
So, after a cursory checkout this darling will be right off to a employer-sponsored calibration when it arrives. Jammy Git rewarded with a Glen Scotia 'Victoriana' (mmmmhhh!)

I'm looking at sourcemeters now.

Anyone interested in my former HP4261A (fully working, no accessories, with IEEE488)?

[Mortymore]

OK! I have to jump in here too, with some of my HP calculators.

3 photos, one of them bd139 style 

[Kosmic]

So in the lot I got in Vermont sometimes ago, I had a box full of power transistors. Mostly, TI SP7388B and S 42SE236. Pretty cool but I can't find any info on those parts. It's like they never existed. I tried looking them up on some sites (alltransistors.com, etc ..) but found nothing.

Anybody know what they are and where I could find the specs ?

[Neomys Sapiens]

OK! I have to jump in here too, with some of my HP calculators.

3 photos, one of them bd139 style 

Hmmm, Nos. 1,2 and 4 look so....curvy? On multimeters, this has incurred the wrath of a certain ElectroDetective!

Is that a isolated scope or is ISO-tech just a name?

[tggzzz]

Ding!

[Neomys Sapiens]

So in the lot I got in Vermont sometimes ago, I had a box full of power transistors. Mostly, TI SP7388B and S 42SE236. Pretty cool but I can't find any info on those parts. It's like they never existed. I tried looking them on some sites (alltransistors.com, etc ..) but found nothing.

Anybody know what they are and where I could find the specs ?

Can't place that 'S' right now - Siliconix? Sprague? Semitron? Semicoa? Semtech?