Hi.
to face off a heatsink you need a completely different tool.
I have seen 6inch diameter (and bigger) mills set up for facing.
The set up procedure is quite complex to ensure the workpiece is exactly at right angles to the milling axis, in both directions, and that the travelling bed is also at right angles to the milling axis.
A simpler DIY method is needed.
How about gluing a fine al oxide paper down to a flat bed and inverting the heatsink on that, then rubbing down.
to face off a heatsink you need a completely different tool.
I have seen 6inch diameter (and bigger) mills set up for facing.
The set up procedure is quite complex to ensure the workpiece is exactly at right angles to the milling axis, in both directions, and that the travelling bed is also at right angles to the milling axis.
A simpler DIY method is needed.
How about gluing a fine al oxide paper down to a flat bed and inverting the heatsink on that, then rubbing down.
Not that kind of unevenness. I mean whole sections are raised about 1.5 mm. It's like they didn't facemill the whole thing at the same depth.
Actually I tool a 1/2" drill bit, cut it off and shaped the end with a rotary tool so it would cut somewhat, and that sort of worked in the drill press. I managed to shave off these areas on one of the heatsinks I was testing, but it's very rough so sanding is still needed, not to mention it was slow ging. I wish I could afford a mill...
Actually I tool a 1/2" drill bit, cut it off and shaped the end with a rotary tool so it would cut somewhat, and that sort of worked in the drill press. I managed to shave off these areas on one of the heatsinks I was testing, but it's very rough so sanding is still needed, not to mention it was slow ging. I wish I could afford a mill...
Hi,
1.5mm is some unevenness!
Filing those lumps off is going to be hard work.
Trying grinding them off to about 0.1mm to 0.2mm high.
Then al oxide 80 or 100grit moving through to 320 or 400grit.
Glasspaper will be too soft and blunt too quickly
You could use emery or silicon carbide instead of al oxide but the grit ranges available over the counter are very restricted.
sandpaper does not exist- it damages your health too much
1.5mm is some unevenness!
Filing those lumps off is going to be hard work.
Trying grinding them off to about 0.1mm to 0.2mm high.
Then al oxide 80 or 100grit moving through to 320 or 400grit.
Glasspaper will be too soft and blunt too quickly
You could use emery or silicon carbide instead of al oxide but the grit ranges available over the counter are very restricted.
sandpaper does not exist- it damages your health too much
get a decent X-Y axis table on your drill press and buy a 1/2" endmill, they're cheap, and will work very well.. high bit speed, decent feed rate, you'll get it pretty close to perfect, with maybe 0.1mm variance, and that will be very easy to sand. Also, when sanding heatsinks you want to start with a course sand paper, and move down to 2000 grit with water, get a sheet of 3mm or so glass, and set the sand paper on it, dont glue or tape it, and use water to hold it down, the surface tension will be enough, sand in a linear motion, not circular, and within an hour you'll have a mirror. I use to be very big into computer overclocking, and spent countless hours making heatsinks, water blocks, etc. all on a drill press with some simple mods.
on a tangent, I managed to get an AMD athlon to sit at a nice -50°C temp, at 100% load, running at 150% its rated clock speed
HTH,
Daniel
on a tangent, I managed to get an AMD athlon to sit at a nice -50°C temp, at 100% load, running at 150% its rated clock speed
HTH,
Daniel
Hi nixie
I own and use both a drillpress and a small geared head multispeed milling machine. I'm sorry to say this but I think a drillpress (made in China?, belt driven and as eccentric running as they come) is completely unsuitable for use as a milling machine. You can't move the head or the bed and moving the piece by hand under a cutter is too dangerous. Aluminium will get 'grabbed' by the cutter and rip the workpiece out of your hands or even your hands into the cutter. Most of today's affordable drillpresses are not running true at firsthand experiences. I even had a technician from drillpress importers in my workshop to try and straighten things up with three different brandnew presses and this was only partially successful.
Believe me, I know all about trying to grind things flat by hand. I sat once for an entire weekend with a woodsaw (the flat surface!) and grinding paste, regrinding o/h cam auto engine shims...
The best idea I can come up with (apart from a milling machine, a good quality milling vice and flycutter) would be to try and use/buy a random orbital sander with variable speed. I've used such a machine with reasonable success to get a fairly flat surface. Depending on which country you live in, you may find it useful to join an experimental engineering society like I have done, here in Cape Town. These societies usually have all kinds of machine tools for the use of by members.
bulgin
I own and use both a drillpress and a small geared head multispeed milling machine. I'm sorry to say this but I think a drillpress (made in China?, belt driven and as eccentric running as they come) is completely unsuitable for use as a milling machine. You can't move the head or the bed and moving the piece by hand under a cutter is too dangerous. Aluminium will get 'grabbed' by the cutter and rip the workpiece out of your hands or even your hands into the cutter. Most of today's affordable drillpresses are not running true at firsthand experiences. I even had a technician from drillpress importers in my workshop to try and straighten things up with three different brandnew presses and this was only partially successful.
Believe me, I know all about trying to grind things flat by hand. I sat once for an entire weekend with a woodsaw (the flat surface!) and grinding paste, regrinding o/h cam auto engine shims...
The best idea I can come up with (apart from a milling machine, a good quality milling vice and flycutter) would be to try and use/buy a random orbital sander with variable speed. I've used such a machine with reasonable success to get a fairly flat surface. Depending on which country you live in, you may find it useful to join an experimental engineering society like I have done, here in Cape Town. These societies usually have all kinds of machine tools for the use of by members.
bulgin
Here's what I used to get the rough cut, and now looks like it's reasonable to sand the rest down (this was simply some old wood filing bit):
The press quill actually doesn't have significant horizontal play when either fully retracted or fully extended. The biggest problem I had actually was that the heatsink fins were not quite identical in height, so one side of the heatsink was about a mm higher than the other one when resting on the stand, so I had to adjust the height as I was moving across several times.
I do wish I had an orbital sander. Renting one here is like $15 for a day
And then there's this: http://www.pathcom.com/~vhchan/cnc/cnc.html
He made a CNC out of the same drill press and an X-Y table, with some significant modifications (I'd need a lathe to do what he did).
An externally hosted image should be here but it was not working when we last tested it.
The press quill actually doesn't have significant horizontal play when either fully retracted or fully extended. The biggest problem I had actually was that the heatsink fins were not quite identical in height, so one side of the heatsink was about a mm higher than the other one when resting on the stand, so I had to adjust the height as I was moving across several times.
I do wish I had an orbital sander. Renting one here is like $15 for a day
And then there's this: http://www.pathcom.com/~vhchan/cnc/cnc.html
He made a CNC out of the same drill press and an X-Y table, with some significant modifications (I'd need a lathe to do what he did).
Yeah, I sort of figured that. If you would happen to be interested in some such equipment that is more affordable for the home hobbiest, you might check out several places in your area: Harbor Freight, Grizzley in Bellingham, and Enco down in Seattle, if you ever make it across the border that is. Small mills are now available for small nondemanding jobs that do not cost alot. Till then, I'm sure you can work with the drill press, just keeping in mind to be careful. With the amount of metal removal you're talking about you'll be ok. A drill chuck will have more runout and is not really equipped to handle an endmill in a lateral movement but is indeed made to go vertical only. You'll more likely bind up if anything, or maybe even jerk the chuck out of the taper (if it's so held that way) I don't think I'd tempt it knowing what I know but would at least try to do it the way it would be done in a machine shop. That's why I mentioned the endmill holder. Aside from that, your press table will need to be aligned to avoid scalloping and you'd probably need a dial indicator or two for measurement. All this is on the assumption you have an x-y table to also work with, otherwise I would not even try it. I've run into the same problems as everyone else over the years realizing that it's not really so simple to even drill a round hole in metal stock. That's why I broke down and now have a machine shop of sorts. Otherwise, you'll be putting in a lot of time getting somewhat mixed results. Tis a fact of life I reckon, just depends on what you're after. Please be safe regardless, stuff happens and metal working is not really to be taken so lightly when power tools are involved.
Actually I really like what that guy did to modify the drill press; the thing is, I don't have a lathe to bulid a new spindle shaft. Is there anywhere I would be able to buy one instead?
Seems this is the cheapest solution; all I have to do is add an X-Y table, one more screw, and three stepper motors.
I guess the downside is that it won't be usable as a drill press anymore...
Seems this is the cheapest solution; all I have to do is add an X-Y table, one more screw, and three stepper motors.
I guess the downside is that it won't be usable as a drill press anymore...
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