Test Equipment Anonymous (TEA) group therapy thread

[bd139]

I just bought a roll of 450x AVX 10uF 16V ones for £8 for general use as an example of possible pricing but that’s a little too close to the 15V rail for comfort.

Definitely. I've twice had a 15V tant on a 13V rail go short circuit (a strange 13V rail in a 485). That's easy to spot, since the associated 81.6ohm resistor visibly changes value.

I assume the 81.6 ohm violently turns to several Gohms?

I bought the 16v ones to run in on 3.3 and 5v rails for the sake of overkill

I just bought a roll of 450x AVX 10uF 16V ones for £8 for general use as an example of possible pricing but that’s a little too close to the 15V rail for comfort.

Definitely. I've twice had a 15V tant on a 13V rail go short circuit (a strange 13V rail in a 485). That's easy to spot, since the associated 81.6ohm resistor visibly changes value.

Do you think 5V headroom enough? I just ordered some 20V AVX tants for the 15V rail on my 2465B's A5.

I’d be happy with that.

Got to say that the new AVX SMD line tants are quite robust. You can’t blow them up. At best they get hot and fall off the board. TH ones don’t fall off so I’m not sure what the outcome is there.

[bd139]

Penis fingers strikes again. Thou shall remember MCP1700 is an LDO and thus the input voltage is max 6v. Also thou shall make sure the output switch is off on your power supply before you power it up in case the last voltage you had set it to was 32V.  Cue SOT23 bouncing off the ceiling. 

[Specmaster]

So that textured finish on your ceiling is less of a design feature and more of accidental one caused by the various electronic components over the years that you've tried to propel skywards. Shouldn't think SWMBO or your power supply are feeling particularly happy  about that

[tggzzz]

I just bought a roll of 450x AVX 10uF 16V ones for £8 for general use as an example of possible pricing but that’s a little too close to the 15V rail for comfort.

Definitely. I've twice had a 15V tant on a 13V rail go short circuit (a strange 13V rail in a 485). That's easy to spot, since the associated 81.6ohm resistor visibly changes value.

Do you think 5V headroom enough? I just ordered some 20V AVX tants for the 15V rail on my 2465B's A5.

Don't know. What does the parts list specify?

One attitude is that if they blow, they blow - and can be replaced, unlike the contents of the NVRAM

[bd139]

If it's old Tek, probably 16V

[glarsson]

Also thou shall make sure the output switch is off on your power supply before you power it up in case the last voltage you had set it to was 32V.

I guess you are not alone and that is probably the reason why HP/Agilent 663xx "power supplies" powers up with the output set to 0.000V and disabled. 

[bd139]

Yes. I'm after a slightly older E3631A for that reason. This is a TTI PL310 which has manual controls.

Just bought some PIC10F320's to play with. 6-pin SOT-23 package. 8 bit CPU, PWM, ADC, configurable logic cell all for £0.35 a go. What glorious times we live in!

[mnementh]

I just spent $160 on storage bins. Hoeing out the garage hurts in more ways than just my back.


mnem
Ouch.

[Specmaster]

Been there myself, fitted my lab out with shelves and boxes from the useful box company to store parts in. still haven't completed the exercise yet but it leaves a big hole in the wallet dept thats for sure.

[tautech]

Good rule of thumb for Tants is to over rate the voltage to as high as is available. I get 50V versions of any I buy.

[Specmaster]

Good rule of thumb for Tants is to over rate the voltage to as high as is available. I get 50V versions of any I buy.

Good practice to at least try and double the nominal voltage.

[bd139]

I’m going to see if I can blow up some of these when they arrive. I’m intrigued to see how close to the line you can push them. I’ve got 450 of them to blow so might as well sacrifice a few for science.

Edit: there’s one roll left if anyone wants them. Just offer 8 - auto accepted: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F272767452677

Remember though the line is positive on SMD tants  not negative!

[mnementh]

£12.88 postage to the US... 

Has anybody experimented with subbing MMLCs for these ubiquitous blighty tants; at least on the more popular models like the Tek 465/24xx families? Or is the hassle of calculating necessary value vs derating/exponentially lower ESR just not worth it?


mnem
Things that make you go "Hmmm..."

[tautech]

Now it's fixed, I can use it to make a proper rip fence for my huge-arse table-saw; got me some old bed frames to cut up for angle iron. 

mnem
Oh, and my Keto diet is going gangbusters as well. Averaging 20 grams/day without suffering too much at all; sometimes even have enough left over for a little morsel of dark chocolate as a bedtime treat.

How huge arsed ?
Pics ?

 
Craftsman Model 113; 10"/3HP. Cast iron deck, with both cast iron extensions. Weighs almost as much as a mnem. 

Here's a pic of it's huge arse (and mine) from when I was cutting hardwood for my "recycled from and with recycled" patio chair project.  I think I posted about this project before.

Nice, especially with the bench extensions.
As a teenager I did a chippy apprenticeship and we used a Kiwi made treadle bench saw that docked and ripped.
Not precision by any means but only a poor tradesman blames their tools, right ?
Some years later I had enough bits and bobs to build my own but wanted a 3ph unit for the addition grunt it provides. So I knocked up a frame and knowing the table's always too small built it 1.2m long x 1m wide. Deck was 20mm ply, 400mm blade driven with a 3hp 6 pole motor. It was a beast, you could rip 5'' softwood at nearly walking pace and would dock a 14 x 3 (3x14 for you Yanks) in a couple of seconds. Sadly lost on a shed fire a few years back. 

Shortly after we were looking to replace many of the items lost and I came upon the same model that I used as a teenager but it was way down country some 6hrs drive away. They were an all steel fabricated affair called a McKenzie and in their day a pretty good workhorse.
Regardless I grabbed it from our NZ Trademe (like eBay) and asked the seller to hang onto it for a couple of months until we might be down his ways. So when trying to hatch a plan how to get it home some deals went down on Siglent stuff I sell that demanded I pile the delivery into my SUV and drop it to the buyer a few hrs drive past where the sawbench was.  Back-load time, yeha.  Getting it the back was no problem and a comfortable fit and we'd also taken the racks to strap the 8ft roller beds onto the roof.

Bit of a step down from the one I made years back as this one's only 2hp and 12" blade but still big enough for the work I occasionally need it for these days.
Here's a couple of pics, see one is set up with the blade to the right and the other to the left....never realized until now they had this option. 
Mine's a lefty version in the same original colors but considerably tidier than both these.





Oh yeah, I've got one smaller and another much larger that's tractor PTO driven. 

[Cubdriver]

Damn, tautech, that thing's a beast!!  I need to excavate my garage and get mine wired up again (a relatively tiny Canuckian ten incher I got as a floor model back around 2005; it came from a local tool supply store that I should never have set foot in), and also get the router table purchased a few years ago up and running to do the trim for the never ending house renovation I've been in the midst of for seven years now...

-Pat

[tautech]

Damn, tautech, that thing's a beast!!  I need to excavate my garage and get mine wired up again (a relatively tiny Canuckian ten incher I got as a floor model back around 2005; it came from a local tool supply store that I should never have set foot in), and also get the router table purchased a few years ago up and running to do the trim for the never ending house renovation I've been in the midst of for seven years now...

-Pat

Yeah that's the problem with living in an old house.
Start to fix some small thing on one corner and two years later you might be finished but on the opposite corner ! 
Done that a few times in the 35+ years I've been here.

Yeah those saws are poor man's bench and radial arm saw, not brilliant at what they do but effective.
Just takes a few seconds to fold the ripping fence and tuck it downwards and another second to flip the docking fence into place. The blade can be locked for up ripping by way of a beefy fabricated wing nut but honestly it's much safer to use the treadle to hold it mostly right up and for the last little bit stop pushing and fix fingers clear of the path of the blade and raise it right up with the treadle to finish the rip. < that's for short lengths while for sheets you're better to lock the blade in one place.

[mnementh]

Wow...tautech, that saw of yours is a scary monster. I have to admit I'm no woodworker; my medium were always electrons & metal.

I decided to dabble a bit due to literally tripping over this saw on the side of the road; it was complete with rip fence (wrong one though I didn't discover this until well into the restoration process) and miter square; it was missing motor bolts, AZ/EL handwheels and belt. Even as ignorant as I am of woodworking, the master machinist's grandson DID recognize the quality of the beast; I nearly plotzed as the motor hadn't been scarfed by some opportunist even though it was left lying on top of the deck!

I have no idea how I managed to get it home in the back of old Franken-Cruiser; I just remember a lot of grunting and ratcheting tie-downs. I did a bit of shopping online and found some 140mm Bakelite handwheels on AliEx for $4 EACH with shipping, and the right size belt for another $4. Another couple bucks at the local Homeowner Hell got me the few nuts & bolts it needed to hang the motor again; then a month wait for the slow boat from China.

I fabricobbled a lift mechanism with some old cut-down caster wheels and a lever so I could make moving it a little easier; those footle-operated equipment movers are flipping expensive, and I just needed to be able to push/pull it 10 feet in/out of the garage. Once everything was back together and the trunions freed up/greased up, I realized the paneling blade that came with wasn't going to cut the mustard, so another trip back to Homeowner Hell yielded a cheap 24T Irwin rip blade. I figured it wouldn't last half way through the job before I'd have to regrind the points; but much to my surprise, the blade ran smooth and true through several hundred feet of rip and cross cutting tropical oak and cedar and still feels like-new sharp.

The slow blade speed of the belt-drive makes this thing crazy quiet (probably also why the cheap blade worked/held up so well); the only noise you hear is the whoosh from the teeth, a dull growl while cutting and occasional ringing of the blade at the end of a cut. As you can see in the pic from last fall, I made do with a piece of bedrail C-clamped to the deck; my intention is to SLIGHTLY improve on that by means of a cross-angle to engage the existing rail angles and again hold it in place with C-clamps or maybe Vise-grip type welding pliers. I toyed with the idea of trying to fab up rails to work with the "all wrong" rip fence I got with the thing but it didn't happen. That is a VERY low priority now that it's probably going to go down the road (either to my local hackspace or a neighbor) as I'm certainly not going to haul it with me halfway across the country when I move; it'll cost me a fortune in gas.

While I was working on this project Ifni smiled upon me in the form of a couple of Crafstman plunge routers in salvageable condition; one has all the little balls missing in the adjuster mechanism, while the other has the foot plate missing. it was probably attached to a router table, which I need to fab one up to finish all the slats anyways.

We'll see how that works out... my neighbor may inherit the Brown-Jordan patio chair project as well. 

Cheers,


mnem
*Toddles off to ded*

[tautech]

mnem
Are you sure that saw blade is running fast enough ? Tip speed should be 10,000 ft/min, regardless of diameter.
C = Pi * d 

Oh and if it's TCT they give excellent service even though they're a bit harder to drive than a plain steel blade.

I had to do a few  's on the McKenzie when I got it home from the road trip as I think it was originally single phase and the 2hp 3ph mator that came with it was loose, not even mounted and with no twin Vee belt pulley. I had one that was almost perfect ratio, mounted it and the motor and wired in a DOL starter/contactor.
Been goin' great guns ever since.

************
Too many toys !

[Brumby]

Too many toys !

No such thing.

If anything, there's never enough space or time.

(Yep, need a TARDIS)

[tautech]

Too many toys !

No such thing.

If anything, there's never enough space or time.

(Yep, need a TARDIS)

You missed ROOM ! 

***********
Tripping over all the stuff.

[Brumby]

I said space ... that includes room.

It also covers rooms, buildings and land (that you could put buildings on).

[mnementh]

mnem
Are you sure that saw blade is running fast enough ? Tip speed should be 10,000 ft/min, regardless of diameter.
C = Pi * d 

Oh and if it's TCT they give excellent service even though they're a bit harder to drive than a plain steel blade.

I had to do a few  's on the McKenzie when I got it home from the road trip as I think it was originally single phase and the 2hp 3ph mator that came with it was loose, not even mounted and with no twin Vee belt pulley. I had one that was almost perfect ratio, mounted it and the motor and wired in a DOL starter/contactor.
Been goin' great guns ever since.

************
Too many toys !

*Gives a look like a tree full of owls*

Not a clue. I do know the drivetrain appears to be all original; the only thing missing was the belt and a few bolts on the intermediary brackets. I know it cuts awesome and clean, even with that cheap blade, and it never burned the wood, not even a little bit. Honestly, I'm loathe to mess with it in any way, aside from getting a functional rip fence fabricated for it.

Yes, definitely a carbide blade; that's been a minimum requirement of mine on any circular saw since I was about 12 and learned the hard way how poor a value the cheap-cheap blades are. These family of saws appear to have quite a loyal following; due to their brutal weight, they are often bought cheap on CL from folks just wanting to not have to handle their heavy arse any more. That heavy weight does translate into two things: One, a very stable work surface, and two, the huge mass of cast iron drops the resonant frequency to sub-audible range, eliminating almost all the evils that a ringing blade bring with.

The 3HP rating is known to be very optimistic; these use a 1.5HP Continuous-duty capacitor-drive motor capable of delivering 3HP at near LRA, which method the entire power tool industry has taken to using as a "developed HP" rating. You can't fault Craftsman for that; they have to rate their products similarly to be able to compete, and to be comparable to other tools in the same class.

When I first saw it, I thought "Holy BLEEP!ing BLEEP!crackers!!! A 3HP motor on a 10" saw? What'd they built it to cut...? Concrete...?"


mnem
*Back out into the suck*

[bd139]

Is it bad that I have considered attaching one to the front of my car? 

[Brumby]

Is it bad that I have considered attaching one to the front of my car? 

Not at all.

Actually doing it though ......

[Cerebus]

Is it bad that I have considered attaching one to the front of my car? 

Personally I've always thought that a couple of 20 mm Oerlikons would be just the ticket.