# custom heat sink price quote request



## kd5ahl (Aug 25, 2009)

First off, if this post is in the wrong place, please feel free to move it to an appropriate place.

I'm looking to have a couple of custom heatsinks machined, and am wondering how much it would cost.

Below is a drawing for what I'm looking for:










Material: aluminum - I don't think it really matters what alloy.
Tolerances: +0.05" -0.0

Ideally someone with a mill will have some scrap 1" plate and can mill up some triangular sections in a jiffy.

Alternatively, if anyone knows where to buy or has available any triangular bar stock with 7/8" sides, I would be all set.


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## wquiles (Aug 27, 2009)

Just a friendly reply since nobody has said anything yet, and so that you don't feel bad if you don't get an offer from any of us. 

Many of us charge $40 or more per hour for custom work, and this is not based on the cost of the aluminum/parts, but the actual setup time, special operation, or something that needs multiple machines (mill, lathe, drill press, rotary table, etc.) - these are the factors that make some of these projects expensive, specially if making only one piece, and with no way in knowing if it will fit or not (since the machinist rarely has the mating part).

In my custom light posts I detail all of the steps I followed to create a custom light, so that folks can get an idea of what it took to create something. I always get several emails from folks asking me for a quote on the same or similar build, but I hardly ever hear from them once they get my quote, even though I tend to charge in the low side as this is still a hobby for me. 

What I have found these last couple of years is that work for any custom piece/project seems to almost always be priced significantly higher than the person asking is willing to pay. 

Will


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## gadget_lover (Aug 27, 2009)

It took several readings of this post to see that the drawing is one top view and one side view.


I don't have any 1 inch plate. I'd have to cut down a larger round or hex rod and that's a lot of material to remove.

Like Will says, it will take a while to set it up, lots of measuring and ways to mess it up.

Daniel


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## precisionworks (Aug 27, 2009)

> work for any custom piece/project seems to almost always be priced significantly higher than the person asking is willing to pay.


+1

Well said. And your shop charge is only 66% of what I charge 

Lots of my work is one off, and I was fortunate to pick up three new jobs today - the factory where I work is not running on Thursdays or Fridays. Even though these jobs are "custom" in that they will never recur, they are essential parts for the people who brought them in. That type of custom work pays well, as no one else within 30 miles is willing or able to do it. Many jobs in my shop are not unlike the RFQ (request for quote) that appear on this board, but most non-machinists can't imagine the time & tooling that it takes to make even a simple part like the custom heat sink.



> the drawing is one top view and one side view


Don't feel badly. You figured it out before I did.


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## Lyndon (Aug 28, 2009)

My line of thinking was kinda like Will's. I _do_ have some 1" polished Al bar stock that was removed from a machine, but this wasn't a job I want to take on as I normally only do milling as part of a larger project.

If you just want a short length of 1" bar and don't mind filing/cutting it yourself, I'll be happy to support the hobby by sending you a 1.5"x1" piece for the cost of shipping in a USPS flat rate box.

-Lyndon


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## Atlascycle (Aug 29, 2009)

How many of the heat sinks do you want?

Jason


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## Oznog (Aug 29, 2009)

This isn't really a heatsink. There are no fins. Do you need fins, or is it a spreader? How much heat? What's the orientation? Or, what are you trying to do??


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## gadget_lover (Aug 29, 2009)

I think about these things during idle moments. Today's was in the shower.

Making a triangular block that is +.05 -0.0 takes some fairly exact layout. I might be tempted to do it just to see if I can.

The first cut is easy. I envision starting with a 1.25 inch rod. You make a flat side at least .93 inch wide, leaving enough stock to clamp onto something. 

Then you rotate it exactly 60 degrees. Not 59.5 or 60.5 if you want to make the numbers come out. Somehow you clamp it. You make this side flat, just barely intersecting the first side. 

Now you have two sides that are at 60 degrees, both are more than .87 inch.

Rotate exactly 60 degrees again and cut it till it is .90

If my figuring is right, it would then be .90 on each side, which is within the .05 tolerance.

Carefully cut it off a little long, then figure out how to hold it securely while you mill the tops/ bottoms to parallel and the right length.

A 1 inch bar is (according to some rough measurements, just a smidgen too small for this by a few thousandths.

If you start with a bar of HEX, this might be downright easy. It would create a lot of swarf and take a while. 

Daniel


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## precisionworks (Aug 30, 2009)

Daniel - you figured out exactly how to make that part, much like my old boss used to do. This is how he'd machine it:

Make sure the milling vise is indicated dead nuts.

Start with a piece of 1.25" solid rod stock that's at least as wide as the vise jaw + the length of the part. You could start with a 36" long piece & let the "extra" hang to the left of the vise (if you are right handed). 

Lower the end mill or face mill & face off the first side, making note of the depth reading.

Rotate the rod 60.00 deg. This sounds harder than it really is. The fastest way is to use a 60 deg angle plate that comes as part of an angle block set. The sets usually include 1, 2, 3, 4, 5, 10, 15, 20, 25 & 30 deg blocks, and are ground to +/- 20 arc seconds. Starret makes a killer set, Part AG16LM, but it may not be available. Since the set has a 30 deg block, the other two angles on that part are 60 deg & 90 deg.

Machine the second face, rotate & use the angle block again & machine third face.



> figure out how to hold it securely while you mill the tops/ bottoms to parallel and the right length.


If you make the first & last cut with a carefully set cold saw, both ends will be parallel & finished. No second op needed


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## Lyndon (Aug 30, 2009)

I should have clarified that I meant 1" *square* bar!

My approach would have been to 
1) Face both ends of a 1"x1"x1.25" solid
2) Lay out the triangle on one end 
3) Clamp lengthwise in vise, sitting on parallels
4) Adjust one side of triangle parallel, so now the plane at right angles to the face is parallel to table.
5) Mill down to marked out line, rotate and repeat 4,5 twice

Pretty time consuming to get everything clamped right. And that's basically why I wouldn't want to do it.
This would be much easier with a rotary table and a chuck held at right angles to the spindle! If it was a smaller diameter prism I could do it out of round rod held in a collet in a spindexer.



gadget_lover said:


> A 1 inch bar is (according to some rough measurements, just a smidgen too small for this by a few thousandths.


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## kd5ahl (Sep 2, 2009)

dang, a bunch of responses and for some reason it wasn't forwarding them to my email! that's what I get for missing my CPF fix for a while

I'm modifying a diving light head to contain a Luminus SST-90 and I need to be able to mount 3 shark bucks to some kind of heatsinking material.

I'm envisioning the triangular piece mounted to the back side of a slug of aluminum that would conduct heat away from the components and LED and into the aluminum body of the light head.

EDIT: Like this:





Now that I look at it, and I'll have to reverify dimensions, I imagine that the tolerances could be more loose on the + side.

I definitely don't want it too small for the shark buck's though.

I would mount the shark bucks on each face, and run the wires up through holes drilled in the cylindrical slug for the LED

The slug and triangular piece would be screwed together with heat sink compound in between and then dropped into the front of the light head after making electrical connections to the battery cable which exits the rear of the head through a gland.

i did not draw in the mounting arrangement of the triangular piece to the slug, because I can mill that on my lathe.

If I had a mill and horizontal rotary table, I would take some round stock, mill it to diameter on the lathe, and then chuck the part in the rotary fixture and index the part 3x to make the 3 flats. I would do this to the slug itself instead of making 2 parts.

it's frustrating to not have room for a mill!

perhaps if I were to make the long slug in the lathe, and then commission someone to chuck the slug in a horizontally mounted indexer/rotary table, and mill the three flats. How much setup time and milling time would that entail for 2 slugs?

Ideally triangular stock would exist and all I would need to do is saw and drill it! does anyone know where you can buy small pieces of solid triangular bar?

thanks for all the responses guys!


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## Atlascycle (Sep 2, 2009)

How big of a slug of aluminum? making it all one piece makes it easier for me to make. Let me know.....

Jason


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## precisionworks (Sep 2, 2009)

> The slug and triangular piece would be screwed together with heat sink compound in between


IMO, the best & easiest way to make that part is to start with aluminum round stock slightly larger than the major diameter, and about 6" long. Cut the three flats at 60 degree spacing as I outlined about, chuck the oversized round in the lathe & turn the round to needed diameter & part off. Half an hour to 45 minutes would be my guess. My shop rate is $1/minute :devil:


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## gadget_lover (Sep 2, 2009)

kd5ahl said:


> If I had a mill and horizontal rotary table, I would take some round stock, mill it to diameter on the lathe, and then chuck the part in the rotary fixture and index the part 3x to make the 3 flats. I would do this to the slug itself instead of making 2 parts.
> 
> it's frustrating to not have room for a mill!
> 
> perhaps if I were to make the long slug in the lathe, and then commission someone to chuck the slug in a horizontally mounted indexer/rotary table, and mill the three flats. How much setup time and milling time would that entail for 2 slugs?



Just because I'm feeling mischievous....

Did you know you can do milling on your lathe? Especially jobs like this. Think of it as facing each surface.

The angles are not critical, but apparently the lengths of the flats are.

Turn it to size.

Face the end. 

Drill and tap for the screw you will use to attach to the round plug.

Part it a little long, then reverse it to face the other end to your 1 inch length.

Now mount a 4 jaw chuck and put the work in sideways.

Face the exposed part till the surface is wide enough.

Rotate the part 60 degrees and face the new surface.

Do it again.

Bingo.


 

Daniel


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## cmacclel (Sep 2, 2009)

A very good dicussion here. Here's how I would do it.

-Draw up a Triangle in E-MachineShop (Super Simple Cad)
-Import the DXF into Mastercam X3
-Tell it the diameter of tool and origin.
-Hit the go button.


Sorry I could not resist 


Mac


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## kd5ahl (Sep 3, 2009)

Nice one Mac!

I've got to make sure of my dimensions before I go forward on this. But some very interesting ideas have been presented here.


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## Oznog (Sep 3, 2009)

Yeah I'd chuck it in my Sherline rotary table, and just face, rotate, face. Probably just write the G-code for it, I'm good at that. Ugly, ridiculous excuse for a language, but low level control is so helpful.


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## LEDobsession (Sep 4, 2009)

cmacclel said:


> A very good dicussion here. Here's how I would do it.
> 
> -Draw up a Triangle in E-MachineShop (Super Simple Cad)
> -Import the DXF into Mastercam X3
> ...



Haha! Thats what I would do too. :thumbsup:


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## kd5ahl (Sep 22, 2009)

It's Done!

Thanks to member atlascycle, I have the heatsink (spreader) that I wanted for my project.

My project is a modification to a diving light, to increase light output by upgrading the LED, and also to widen the beam for use in underwater video.

Here's what I ordered from atlascycle:












and Here's what I did with it:
















Obligatory Beamshots once the batteries finish charging. 

EDIT: Okay Beamshot Time!

First shot taken with light head about 4 feet off the ground and 6 feet from the concrete wall.





Second shot with the light moved to 3 feet from the wall.


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## darkzero (Sep 22, 2009)

Very nice, I like! :twothumbs


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## wquiles (Sep 22, 2009)

I like the end result - very nice work indeed. I must note, however, that given the pictures of how the heatsink was actually used, that several of the heatsink's tolerances in the design were *far more* accurate than was really needed, for example these two:

- the 1.00" +0.05 - 0.0
- the 0.87" +0.05 - 0.0

Since there was so much empty space around the drivers, the tolerance for those could have been much more looser - in fact, they don't even have to be exactly the same on all sides. Keep this in mind for a future project as it will certainly be cheaper to make, and more folks will be more eager to try to make it 

Will


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## gadget_lover (Sep 22, 2009)

And now the $64,000 question: How close to the dimensions did he make it? Did all three sides match? 


Daniel


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## Atlascycle (Sep 23, 2009)

The Parts were made on a 2 axis CNC Bridgeport Mill.

And as for the tolerances, 0.050" is a pretty forgiving tolerance, so in my eyes the 0.87" dimensions turned into 0.895 +-0.025"

Now .0005 on the other hand......


Jason


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## wquiles (Sep 23, 2009)

Atlascycle said:


> The Parts were made on a 2 axis CNC Bridgeport Mill.
> 
> And as for the tolerances, 0.050" is a pretty forgiving tolerance, so in my eyes the 0.87" dimensions turned into 0.895 +-0.025"
> 
> ...



Nice job Jason. Now all you need to do is to share with us a pic of your setup - we love seeing pictures of our toys :twothumbs

Will


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## Atlascycle (Sep 23, 2009)

wquiles said:


> Nice job Jason. Now all you need to do is to share with us a pic of your setup - we love seeing pictures of our toys :twothumbs
> 
> Will



I suppose I could Recreate the setup 


Jason


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## wquiles (Sep 23, 2009)

Atlascycle said:


> I suppose I could Recreate the setup
> 
> 
> Jason



Just meant a photo or two (or ten!) of your machine, area, etc.. - just anything you can share with us


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## Atlascycle (Sep 23, 2009)

wquiles said:


> Just meant a photo or two (or ten!) of your machine, area, etc.. - just anything you can share with us



The Machines are not mine, I am very fortunate to work for a company that will let me have the run of the shop. I have at my disposal a arsanel of surface grinders (6x12 up to 14x40) 2 lathes, 6 bridgeport mills, one extrak mill, and the shop also has a Haas TM-3 and two Wire EDMs

Jason


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## wquiles (Sep 23, 2009)

Atlascycle said:


> ... I have at my disposal a arsanel of surface grinders (6x12 up to 14x40) 2 lathes, 6 bridgeport mills, one extrak mill, and the shop also has a Haas TM-3 and two Wire EDMs ...


  

(those above are little guys drooling!)

Man, that is awesome - lucky indeed :twothumbs

Will


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## kd5ahl (Sep 23, 2009)

Will,

Thanks for the kind words. I will definitely be thinking about the tolerances in the future.

In retrospect, I had already padded the diameter to allow me to machine to fit on the lathe, so I could probably have settled on +any amount -0 for tolerances and machined whatever extra down to what I needed.

the -0 was the critical one in my mind as I did not want a loose fit for the spreader in the light head, or too little room to mount the drivers comfortably.

Jason, I will definitely be offering you more opportunities to do work on projects of mine as soon as I get some more ideas!

How does your mill like to eat cast acrylic?

Good work, and good advice from everyone.


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