Pumpkin preamp - More Boring Making Thread - Page 31

Zen Mod · 2nd February 2008, 04:48 PM

Quote:

Originally posted by Manu

Zen Mod · 2nd February 2008, 06:57 PM

me thinks that they're olde americanino Lewyt xformers , which truly yours personally butchered from olde americanino WWII xmiter ..... on junkyard ......... where else ?

one xmitter - one xformer

3K6:18K

something like this - from machmat pagines :

Manu · 4th February 2008, 06:41 PM

Nothing broken today...
Hehe.

But you sowed doubt in my mind about the method used to thermal coupling the Zistors.

Would Schrumpfschlauch/Heat-shrink tubing/Krimpkous (thats for frère Jacques) instead of tie-Wrap be a better solution?

Manu
Anxious

Zen Mod · 4th February 2008, 06:47 PM

Quote:

Originally posted by Manu
Nothing broken today...
Hehe.

But you sowed doubt in my mind about the method used to thermal coupling the Zistors.

Would Schrumpfschlauch/Heat-shrink tubing/Krimpkous (thats for frère Jacques) instead of tie-Wrap be a better solution?

Manu
Anxious

why not ?

same length/height as tie-wrap - leaving exposed as much you can of eeny weeny TO92

Magura · 5th February 2008, 04:24 AM

Quote:

Originally posted by Manu
Nothing broken today...
Hehe.

But you sowed doubt in my mind about the method used to thermal coupling the Zistors.

Would Schrumpfschlauch/Heat-shrink tubing/Krimpkous (thats for frère Jacques) instead of tie-Wrap be a better solution?

Manu
Anxious

No, it would not offer any tension once just around 45C, cause it turns soft at that temperature.

Zip ties or metal is the way to go.

Magura

Zen Mod · 5th February 2008, 10:11 AM

Quote:

Originally posted by vitalstates

here ya go :

http://www.axminster.co.uk/pricing/I...rill-22285.htm

but mine is not as sexy as the one shown in the pic

Ed

what's point ?
in through hole you make or in bigger dia hole ,than you need ?

through hole is a must - in 90% of situations , and exact dia for tap is easy to find ;

trick is in steady , slow drilling , lubricating is a must ( WD40 is handy , even if I use some more esoteric stuff - and you don't wanna know that's in fact nothing else than goat fat).

tapping - again lubricating is must ;
half turn right , then half turn back ........
coffee is obligatory , too .......
and no hurry

sounds easy ?

Manu · 5th February 2008, 11:36 AM

Quote:

Originally posted by Zen Mod

what's point ?
in through hole you make or in bigger dia hole ,than you need ?

through hole is a must - in 90% of situations , and exact dia for tap is easy to find ;

trick is in steady , slow drilling , lubricating is a must ( WD40 is handy , even if I use some more esoteric stuff - and you don't wanna know that's in fact nothing else than goat fat).

tapping - again lubricating is must ;
half turn right , then half turn back ........
coffee is obligatory , too .......
and no hurry

sounds easy ?

For tapping in soft material like Al, I now prefer to use Hand tapping tool as I ended having must less broken tap than with drilling machines. I found that, this way, it is so much easier to control.
Lubrification with common lamp-oil (cheap) but I am not a profi.

For drilling, the opposite. I prefer pillar drill (broken drill on ZenMods pic is the result of free hand drilling on kitchen table, smoking and drinking a beer at the same time)

jacco vermeulen · 5th February 2008, 12:37 PM

redrill the bottom of the hole with a broken drill, you'll have more clearance for the debris, which makes the threading easier.

(me made lots of 50 cents/hr for tapping big holes during child slavery years)

pssst: anyone in Ostricha(or other Birdy-ca) interested in sharing a switcher dump ?

yggdrasil · 5th February 2008, 04:35 PM

For tapping I use a guide of some sort, usually a piece of wood with a tight hole for the tap.

The guide is clamped onto e.g. the heat sink.

DaveM · 5th February 2008, 04:59 PM

For tapping aluminum there are some tricks. Using a pillar drill or drill press as I know them is certainly helpful. If you are specifically talking about drilling heatsinks, I have often had the problem of the drill location coming out the other side partially on a sink fin. This will cause the bit to bend away from the fin and snap.

I use WD-40 as a lubricant when I don't have magic tap aluminum at hand. That stuff works better than anything else I have tried. It reduces broken drills and taps considerably. So, the trick is to mark the hole location as needed and start the hole dry. This will allow you to accurately locate the drill point on the mark. Once there is a small divet started, add you lubricant and begin drilling. With a pillar drill and a small bit, be very careful not to apply too much pressure. So drill down a bit and then lift the bit up and out of the hole. What you want to see is the aluminum in the flutes of the bit spin free as the bit comes out of the hole or as you plunge back into the hole, the aluminum should ride up the flutes and fall away. If you see that the material in the flutes is not clearing, you should stop and use a pick to get it out. When you break a bit 90% of the time it is caused by the material loading in the flutes and binding in the hole. Don't allow the material to load up in the flutes. Depending on the depth of the hole, put a drop of oil in the hole midway through the hole. You can tell if you need more oil if the flutes are not ejecting the chips well.

Tapping follows the same rules. Keep the chips out of the hole and you shouldn't have an issue.

2nd February 2008, 06:57 PM	#302
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	me thinks that they're olde americanino Lewyt xformers , which truly yours personally butchered from olde americanino WWII xmiter ..... on junkyard ......... where else ? one xmitter - one xformer 3K6:18K something like this - from machmat pagines : __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb

5th February 2008, 12:37 PM	#308
jacco vermeulen diyAudio Member Join Date: Oct 2004 Location: At the sea front, Rotterdam or Curaçao	redrill the bottom of the hole with a broken drill, you'll have more clearance for the debris, which makes the threading easier. (me made lots of 50 cents/hr for tapping big holes during child slavery years) pssst: anyone in Ostricha(or other Birdy-ca) interested in sharing a switcher dump ? __________________ Not so much,.......if it says "ZM" in the corner.

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4th February 2008, 06:41 PM	#303
Manu diyAudio Member Join Date: Nov 2002 Location: Vienna, Ostrich	Nothing broken today... Hehe. But you sowed doubt in my mind about the method used to thermal coupling the Zistors. Would Schrumpfschlauch/Heat-shrink tubing/Krimpkous (thats for frère Jacques) instead of tie-Wrap be a better solution? Manu Anxious

5th February 2008, 04:35 PM	#309
yggdrasil diyAudio Member Join Date: Sep 2005	For tapping I use a guide of some sort, usually a piece of wood with a tight hole for the tap. The guide is clamped onto e.g. the heat sink.

5th February 2008, 04:59 PM	#310
DaveM diyAudio Member Join Date: Feb 2003 Location: Vermont	For tapping aluminum there are some tricks. Using a pillar drill or drill press as I know them is certainly helpful. If you are specifically talking about drilling heatsinks, I have often had the problem of the drill location coming out the other side partially on a sink fin. This will cause the bit to bend away from the fin and snap. I use WD-40 as a lubricant when I don't have magic tap aluminum at hand. That stuff works better than anything else I have tried. It reduces broken drills and taps considerably. So, the trick is to mark the hole location as needed and start the hole dry. This will allow you to accurately locate the drill point on the mark. Once there is a small divet started, add you lubricant and begin drilling. With a pillar drill and a small bit, be very careful not to apply too much pressure. So drill down a bit and then lift the bit up and out of the hole. What you want to see is the aluminum in the flutes of the bit spin free as the bit comes out of the hole or as you plunge back into the hole, the aluminum should ride up the flutes and fall away. If you see that the material in the flutes is not clearing, you should stop and use a pick to get it out. When you break a bit 90% of the time it is caused by the material loading in the flutes and binding in the hole. Don't allow the material to load up in the flutes. Depending on the depth of the hole, put a drop of oil in the hole midway through the hole. You can tell if you need more oil if the flutes are not ejecting the chips well. Tapping follows the same rules. Keep the chips out of the hole and you shouldn't have an issue.