My new Toy!! Lathe question

So my Uncle has this beauty just sitting idle in his shop, I can't believe he never told me!!!!

I'm going to spending quite a lot of time at his shop now.

It's a SouthBend.

Question: What size bit should I use to fit an AixiZ module in a heatsink? I tried a 15/32 and it came out a tad big. I think it's usable with a set screw and some thermal compound but I'd like it tighter.

Thanks guys!!! :beer:

no you should be able to use a 15/32 perfectly.
But you have to do a few things first.
One heat the work piece up i use a small coffee cup heater. plugs into wall while the work piece sits in a cup and warms up.
Then once its nice and warm close to HOT!, (might want gloves) drill threw. once it cools it should be a nice tight fit. also if you have a lathe you can always turn the 15/32 bit down a bit.
remember just a tiny bit.
Also make sure you are dilling holes in stages.
use a smaller bit to make the first hole and then one more a bit smaller than the 15/32 and then use the 15/32
if you are using the 15/32 alone you will have a large hole.
you need to work up to it. i use 4 bit
this is order from last to first
15/32,7/16,3/8
sometimes the 15/32 is a to small and i have to sand a bit or pull our my 12mm bit.
But normally i just can press them in with a vice.
Also a trick to make your heatsinks better.
Only drill the 3/8 all the way threw for the wires.
Then dont use the back of the aixiz housing just use the head. and drill the next 2 holes just enough to fit it in. that way you have more thermal mass and still a hole for the wires.
of course if you are not using a chip driver/led style you might still need it for your driver. but those one from DX work great and take up very little room.
I hope this helps you.
If you need any advice let me know.

Drill chart:

Drill Bit Size Chart

Drill Size Chart

Remember some holes are made with adjustable boring bars, ie any thing non standard.

Then order the right bits, either metric or standard:

Industrial Supply Equipment from MSC Industrial Supply

McMaster-Carr



Steve

or just go to harbor freight. if you live in the us.
you can get a great set of drill bits for cheap.

Thanks for the info and links!! :beer:

The one that I did, I started with a "starter bit" or "boring bit", then went one size (drill bit) bigger, then right to the 15/32 bit. So maybe next time I'll try the four different steps.

dont forget to heat to work peice before you bore the 15/32. it seems to help alot.

kiyoukan said:

dont forget to heat to work peice before you bore the 15/32. it seems to help alot.

Click to expand...

Remember that all 15/32's are not the same. I tried several bits
in that size till I found the closest.

You might go through 5 different makes of bits, but when you find
the one that is the nearest match, simply buy more...

It will help with tolerance giving better consistency, and save
the extra time needed to heat the work..

:beer:

if you have a 15/32 bit and need a tiny bit taken off you have a lathe just take a bit

I'm going to try heating up the Al stock and see if that works. I'm using my Uncle's bits right now and I don't think he's going to like the idea of me turning down one of them.

In the future I'll buy my own. Thanks wannaburn, I will try different companies too. :beer:

Good luck. also if you want i have 12mm drill bits. i bought an order of 5 but i only use one.
If you want o can send you a 12mm bit and you can lathe it down.

kiyoukan said:

Good luck. also if you want i have 12mm drill bits. i bought an order of 5 but i only use one.
If you want o can send you a 12mm bit and you can lathe it down.

Click to expand...

LOL. :crackup:

Thank you very much for the offer. I'm laughing because I think those were the bits I traded you for some heatsinks you made for me. :yh:

Kevlar said:

LOL. :crackup:

Thank you very much for the offer. I'm laughing because I think those were the bits I traded you for some heatsinks you made for me. :yh:

Click to expand...

Karma = What goes around, comes around. :angel:

kiyoukan said:

if you have a 15/32 bit and need a tiny bit taken off you have a lathe just take a bit

Click to expand...

You could do that, but you also alter the integrity of the bit.

Funny enough, the bit that I found to work best was from a hardware
store in the middle of nowhere out by my brother in laws cottage.

I threw away the package, so im not sure of the make. It was some
brand ive never heard if, but a good quality compared to what is sold
locally by the usual retailers.

If he goes up there anytime soon, I will take a road trip to get more
and note the name of the manufacturer...


*EDIT*

@Kevlar

You can always take a pair of calipers along with you to the
hardware stores you visit. Measure them before you buy
and save some money in the process.

well if you want just tell me and ill send you a 12mm bit. but they do need to be shaved down a bit. as the hole will come out 12.1mm

Have you tried reamers for the work you want to do ?
.1560" - .2155" Chucking Reamers In .0005" Increments - Carbide Tipped - Straight Shank from Super Tool, Inc.
There are also flexible hand operated incremental reamers for when you only need to remove very small amounts of metal after you've gotten the part as close as possible with the reamer you have.

Success!! I've completed my first heatsink!! This is for the Ultrafire 501B



@Steve001. Thanks for the tip, but I have no idea how to use em. :thinking: