[Fishline]

You guys are incredibly helpful! If I may ask one more: short of a stepped bit, what kind of bit can work on an aluminum case? It seems like most common power drill bits only go up to 1/2". Do twist bits go up to 5/8"?

 

[dsavitsk]

I use these all the time. I'm sure it's a bad idea, but in aluminum they seem to do just fine.

 

[cwboomer]

The spade bits are technically meant for wood. Generally anything that has a carbide edge will cut aluminum. And wood bits will cut aluminum for a short time, until they dull too quickly. No quicker than really hard tropical woods.

Enco - Guaranteed Lowest Prices on Machinery, Tools and Shop Supplies

here's an individual "twist" drill bit. Probably as cheap as a spade bit. They also have nice hex headed hardware. This is a "jobber" length, meaning much longer than you'd find at a home center. It's for the metalworking trade.

dan

 

[cwboomer]

Quote:

Originally Posted by cwboomer /img/forum/go_quote.gif The spade bits are technically meant for wood. Generally anything that has a carbide edge will cut aluminum. And wood bits will cut aluminum for a short time, until they dull too quickly. No quicker than really hard tropical woods. HTML Code: [left]http://www.use-enco.com/CGI/INSRIT?PMAKA=300-0140&PMPXNO=943186&PARTPG=INLMK32[/left] here's an individual "twist" drill bit. Probably as cheap as a spade bit. They also have nice hex headed hardware. This is a "jobber" length, meaning much longer than you'd find at a home center. It's for the metalworking trade. dan

There's also these, but be darn careful and use a drill press:
Enco - Guaranteed Lowest Prices on Machinery, Tools and Shop Supplies

 

[kuroguy]

Just make sure to use lots of oil when cutting aluminum and wood bits will last pretty long. I use regular 40 weight in a pump style oil can. So long as you keep the bit cool, the edge will last.

 

[scompton]

Stepped bits don't have to be expensive

Harbor Freight Tools

 

[Llama16]

Does someone happen to know where I can get the European (belgian) version of the powersupply? Byt his I mean the one meant for 230V (220V-240V) network.

 

[tomb]

Quote:

Originally Posted by Llama16 /img/forum/go_quote.gif Does someone happen to know where I can get the European (belgian) version of the powersupply? Byt his I mean the one meant for 230V (220V-240V) network.

The existing supply works on 240V. You'll probably need to get an adapter for the connector, but there are many European folks who use the same power supply as I understand it.

 

[tomb]

Quote:

Originally Posted by scompton /img/forum/go_quote.gif Stepped bits don't have to be expensive Harbor Freight Tools

Yep - all I use! Use the 1/4 - 3/4 bit, though. The other two are not so hot, IMHO - especially the big fat one (the long one is ~OK). They go dull fairly easily on the very tip, but heck - they're so cheap that I go buy some more.

 

[cwboomer]

Quote:

Originally Posted by kuroguy /img/forum/go_quote.gif Just make sure to use lots of oil when cutting aluminum and wood bits will last pretty long. I use regular 40 weight in a pump style oil can. So long as you keep the bit cool, the edge will last.

Agreed, and if you can slow down your speed. slow it down.

Here's a speed guide.
Drill Press Speed Chart

 

[SaxonFSU]

where can you currently get the 19j6 tubes for cheap? and what should you look for when ordering them brand country of manufacture ect

thanks

 

[Llama16]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif The existing supply works on 240V. You'll probably need to get an adapter for the connector, but there are many European folks who use the same power supply as I understand it.

So just a simple socket adapter will do! that's amazing

Just made my day.
the power supply was my biggest concern. I'm glad I'm rid of it

 

[SaxonFSU]

Quote:

Hi everyone, This has been in the works for a while but I finally found some time to put it together. I wanted to modify the starving student amp using an alternative tube to the scarce 19J6's. I finally settled on the 12SR7 and 12SW7 which are only $1 each at vacuumtubes.net. Perfect for the starving student. The caveat is that they are metal tubes and some people may prefer glass tubes. In that case the 12SR7GT is the glass tube version of the 12SR7. It is a few dollars more per tube but still cheap. Here is the result, the metal starving student: If you want to build this version, you have to make some small changes - R1/R7 - 44k R5/R11 - 4K R2/R8 - 330K R4/R10 - 180K You will have to use an octal socket, and here are the conversions from the seven pin socket in the original circuit diagram: 1,2 -> 6 5,6 -> 2 3,4 -> 7,8 7->3 You will also have to ground pin 1 which is for the metal casing. It is probably a good idea to ground pin 1 with a separate path to ground from the heaters (pins 7,8). That way if the ground connection for the heaters breaks for whatever reason you don't see that voltage on the tubes. Using 2" heatsinks is also recommended since the heaters are running at 12V instead of 19V.

i was looking this over and woundering if anyone has any experience, i want to do this because i am having trouble finding 19j6 tubes.

any help would be greatly appreciated because this will be my first tube project.

with this setup is there any other modifications that will need to be made?

thanks in advance

 

[Lou Erickson]

Their website says that vacuumtubes.net has the 19j6 for $4.00 each. They were $1.00 IIRC, so they've gone up a bit, but that's still pretty affordable.

Mind you, that page might be outdated.

Google also finds them for $4.00 at thetubecenter.com. A.G. Tannenbaum lists them for $4.00 each. vacuumtubesinc.com says "call" so who knows if they have any, and vacuumtubes.com lists them for $10 each, which seems high.

Are you hearing from these vendors (particularly vacuumtubes.net who was highly regarded earlier in the thread) that they're out and the web page needs to be updated?

Maybe I'll order myself a set while I'm thinking about it.

 

[tomb]

The next round of 25 Starving Student Millett Hybrid kits will be available beginning Saturday, 11/14/2009 at 12:01 AM EST (Friday night).

EDIT: I haven't talked to them in awhile, but I think both vacuumtubes.net and the Tube Center are out. The only ones that I know have them (besides Beezar) are tube vendors that sell them for $10 or more, such as SND Tube Sales.