What did you buy today? Post your latest purchase!

[Cubdriver]

Plasma on aluminum has never worked well for me. Leaves a really ragged cut. Maybe I'm just doing it wrong.

I've never tried plasma on Al - don't think it would work.  Plasma is for steel.  I might have sown some confusion when I threw in the bit about cutting aluminum on the table saw.

-Pat

[beanflying]

Plasma can cut a bunch of conductive metals including Aluminium, Brass, Copper and some of the whacky steel alloys but you really need to consider playing with the Shielding Gas Nitrogen, CO2 and Argon mixes generally. The same thing applies with metal cutting Lasers too.

Not a fan of Aluminium and Plasma (and I don't have mixed gases) and as I don't build boats saws make most sense for roughing it out.

[Cubdriver]

Plasma can cut a bunch of conductive metals including Aluminium, Brass, Copper and some of the whacky steel alloys but you really need to consider playing with the Shielding Gas Nitrogen, CO2 and Argon mixes generally. The same thing applies with metal cutting Lasers too.

Not a fan of Aluminium and Plasma (and I don't have mixed gases) and as I don't build boats saws make most sense for roughing it out.

Given the load the plasma cutter puts on my air compressor, I can't imagine trying to feed it some specialty gas mixture - that would get expensive REALLY fast!

-Pat

[beanflying]

Yep I used to have a customer that was buying 6 bottles of cutting gas a week but they were building Aluminium Boats You can do thin Aluminum with Air so give it a go sometime, I wouldn't try anything much over 2mm and expect it to look ok.

[Cubdriver]

Yep I used to have a customer that was buying 6 bottles of cutting gas a week but they were building Aluminium Boats You can do thin Aluminum with Air so give it a go sometime, I wouldn't try anything much over 2mm and expect it to look ok.

May take a crack at it at some point, but think by and large I'll stick to non ferrous blades on the table and miter saws for the al-you-min-yum.  (And thankfully have no inclination towards building boats despite the plethora of anchors I have here...)

-Pat

[Cubdriver]

Actually bought them Saturday, but didn't immediately get photos.  Snagged a rather rough looking pair of Dynaco A10 bookshelf speakers for $45.  They were painted at some point (institutional tan #5 - blechh  ), and one of the woofers had a tear in the cone.  Pulled the torn woofer and repaired the rip; it's drying now.  Based on what I've read online, it appears that they originally came out in 1971; if what I think is a date code on the woofer is correct it was made in late 1971 (5071).  They were made in Denmark.  Scraped a bit of the paint off the bottom of one of them and it looks like they originally had a wood finish, so I plan to try stripping the nastiness off & refinishing them, and if all else fails try my first effort at veneering if they're too far gone.









More pics at https://pmanning.smugmug.com/Electronics/Dynaco-A10-Speakers

-Pat

[mnementh]

I was blown away ten or twelve years ago when I finally tried cutting aluminum on my table saw - amazed at how well it went, and immediately went and bought a proper non-ferrous blade for it.  It goes through 1/4” 6061-T6 aluminum like a hot knife through butter and leaves a great finish on the cut.  Based on that, I bought the cold chop saw a few years ago and was similarly impressed.  Not quite as fast as the table saw on the Al, but still plenty quick and a beautiful smooth cut.  So, so, so much better than trying to cut either material with a band or jig saw.

-Pat

Back when I did jig & assembly line fab out of 8020 extrusion, the only thing we used to cut the material was a chopsaw with 14" x 60-80 tooth carbide blade. If set up carefully to ensure it is square, you can get accuracy "within a few thou" with finish rivaling milled surface, especially if you bother to set up your cutoff stops every time so your pairs/sets of beams are exactly the same length.

mnem
 

[mnementh]

Yep I used to have a customer that was buying 6 bottles of cutting gas a week but they were building Aluminium Boats You can do thin Aluminum with Air so give it a go sometime, I wouldn't try anything much over 2mm and expect it to look ok.

*coughWATERJETcough*

mnem
A dwagon can dweam...

[georges80]

Regarding plasma cutting and various materials.

Plasma cutting is essentially melting and blowing away material. So, a good heat conducting material such as aluminium will have a rough edge since the melt zone will be large. Thicker the material, the rougher the cut will be.

You can cut glass too... Just tack down some aluminium foil or conductive thin metal on the glass to allow the arc to form to start the plasma process and then cut away (or more precisely, melt away) 

cheers,
george.

[Ground_Loop]

Regarding plasma cutting and various materials.

Plasma cutting is essentially melting and blowing away material. So, a good heat conducting material such as aluminium will have a rough edge since the melt zone will be large. Thicker the material, the rougher the cut will be.

You can cut glass too... Just tack down some aluminium foil or conductive thin metal on the glass to allow the arc to form to start the plasma process and then cut away (or more precisely, melt away) 

cheers,
george.

Holy crap. I'm going to have to try that.

[jonpaul]

Tektronix 7L5 Spectrum Analyzer plug-ins for 7000 mainframe with OPT 25 tracking generator and L3 front end 50/600/1m Zo

Hardly ever used. I Worked since February with the seller  to get very difficult payment packing and shipping issues cleared up. Just arrived!

Huge double wall box, great packing...

Will test out soon,

Jon

[Cubdriver]

Beautiful!  And with apparently intact knobs - seems to be a rarity for 7k series plug-ins not to have one or more of them bent or broken.  Nice score!

-Pat

[KaneTW]

A Kikisui PLZ205W electronic load.

[chickenHeadKnob]

Regarding plasma cutting and various materials.

Plasma cutting is essentially melting and blowing away material. So, a good heat conducting material such as aluminium will have a rough edge since the melt zone will be large. Thicker the material, the rougher the cut will be.

You can cut glass too... Just tack down some aluminium foil or conductive thin metal on the glass to allow the arc to form to start the plasma process and then cut away (or more precisely, melt away) 

cheers,
george.

won't the resulting pieces have a severely stressed heat affected zone prone to cracking?

[jonovid]

micrometre   -mechanical engineering tool to know how thick something is in millimeters .mm

[beanflying]

micrometre   -mechanical engineering tool to know how thick something is in millimeters .mm

Now you need a second more accurate one or a calibrated gauge block to verify this one  And a Surface plate and a ...........

[Cubdriver]

micrometre   -mechanical engineering tool to know how thick something is in millimeters .mm

Now you need a second more accurate one or a calibrated gauge block to verify this one  And a Surface plate and a ...........

At least TWO more - otherwise how can you really be certain which one is off?

-Pat

[Cubdriver]

I started stripping the A10 cabinets today.  So far I’m hopeful - the veneer in the areas I’ve done so far appears to be in good shape for its age.


Decided I should hook them up and give a listen before spending who knows how long stripping nasty paint.  I’m impressed, given their small size.  They sound pretty good to me - worth the $45 I paid for them.


-Pat

[vk6zgo]

micrometre   -mechanical engineering tool to know how thick something is in millimeters .mm

It would be a micrometer, (ie, a meter for measuring small things) as it is not calibrated in millionths of a metre, but in millimetres & decimal fractions of a mm.

[jonpaul]

Rebonjour a tous....All from flea markets and street sales in Paris...

 Franck-Hertz Critical Potentials   Physics experiment He bulb EU 15


HP 2007 Financial calc NIB French and En manual and case....uses CR2032 Li batts... EU 5



1943 Aviation calc from UK EU30



Besides the HP calc, I have never see this stuff in the USA...

Your thoughts appreciated...
Jon

[jonovid]

micrometre   -mechanical engineering tool to know how thick something is in millimeters .mm

It would be a micrometer, (ie, a meter for measuring small things) as it is not calibrated in millionths of a metre, but in millimetres & decimal fractions of a mm.

I should copy and paste words more carefully, such is the web

[Cubdriver]

Rebonjour a tous....All from flea markets and street sales in Paris...


1943 Aviation calc from UK EU30



Besides the HP calc, I have never see this stuff in the USA...

Your thoughts appreciated...
Jon

An early Whiz Wheel - very cool!     Nice find.

-Pat

[vk6zgo]

micrometre   -mechanical engineering tool to know how thick something is in millimeters .mm

It would be a micrometer, (ie, a meter for measuring small things) as it is not calibrated in millionths of a metre, but in millimetres & decimal fractions of a mm.

I should copy and paste words more carefully, such is the web

Or perhaps I'm just "splitting hairs".

[ledtester]

Some Radio Shack "Science Fair-Style" spring terminals -- like the ones in the XXX-in-1 Project Lab kits:



https://makertradingpost.com/collections/frontpage/products/spring-terminals-pack-of-25

[timenutgoblin]

micrometre   -mechanical engineering tool to know how thick something is in millimeters .mm

Depending on how it's spelt, it's either a measuring unit, or a measuring instrument. Also, depending on how it's pronounced, it's one or the other.

Measuring instrument:
micrometer
/mʌɪˈkrɒmɪtə/

Measuring unit:
micrometre
/ˈmʌɪkrə(ʊ)ˌmiːtə/