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 :
one xmitter - one xformer
3K6:18K
something like this - from machmat pagines :
An externally hosted image should be here but it was not working when we last tested it.
vitalstates said:
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 ?
Zen Mod said:
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)
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 ?
(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 ?
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.
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.
vitalstates said:
maybe you have handy table on back side of your caliper measure thingie ......
if you have it
google is my best friend
http://www.marfas.com/machinescrewtapping.shtml
Drillsize for metric thread. Ofcourse Danish is easy to understand
MM thread = (gevind)
"Gevindbor" = drillsize
"Stigning i mm" = x MM pr. "wrinkle"
"Max. indvendig diam. mm." = absolutely max drillsize
MM thread = (gevind)
"Gevindbor" = drillsize
"Stigning i mm" = x MM pr. "wrinkle"
"Max. indvendig diam. mm." = absolutely max drillsize
What gain setting are you guys using to drive F4 amp? My Xbosoz has a gain of 13 db with stock feedback resisters and my volume is at 3/4 for normal listening on F4. Chocky's documentation states 4.7 - 15X gain depending on R5,R6. I am not sure how that related to 13db gain. If I up gain to 15x with 150k it states to lower C1,C2 mica to maintain same R/C ratio, however the internet calculator I was using increased it (lame engineering skills). Another curious question why is a Ei transformer preferred for this application ( I defer to previous excuse).
Thanks
Bill
Thanks
Bill
es44 said:Drillsize for metric thread. Ofcourse Danish is easy to understand
MM thread = (gevind)
"Gevindbor" = drillsize
"Stigning i mm" = x MM pr. "wrinkle"
"Max. indvendig diam. mm." = absolutely max drillsize
thanks es44 thats exactly what I couldn't find....
also thanks choky but my feeble little excuse for a brain has now gone metric cos its harder to find imperial drills in funny sizes in these parts nowadays
Ed
sorry for barging in, but here are a few more tips for drilling and tapping:
1) use a sharpie to put a little mark on your drill bit to show when you have hit the right depth -- that way you won't drill through
2) I like to use a drill chuck (sans drill) to hold the tap bits. This forces you to turn circles with the tap, rather than pushing on it like you can do with a T-handle. (hey, vector math is useful for something!) The chuck will also slip a bit if you hit a rock, it has saved me more than one tap
3) use a sharpened nail set to punch a little divit in the AL to keep the drill bit from swimming when starting a hole.
good luck, JJ
1) use a sharpie to put a little mark on your drill bit to show when you have hit the right depth -- that way you won't drill through
2) I like to use a drill chuck (sans drill) to hold the tap bits. This forces you to turn circles with the tap, rather than pushing on it like you can do with a T-handle. (hey, vector math is useful for something!) The chuck will also slip a bit if you hit a rock, it has saved me more than one tap
3) use a sharpened nail set to punch a little divit in the AL to keep the drill bit from swimming when starting a hole.
good luck, JJ
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