# Colosssus Heatsink



## cmacclel (Jan 18, 2009)

I machined a few heatsinks the other Day for a LED version of ModaMags Colossus light. Here are the results!

Machined from a 3.750 Solid

Video (Make sure you Full Screen it! Also you can hear the Constant Surface Speed machining)

http://www.vimeo.com/2871556

Pics Below












The MESS!


























3 heatsinks FILLED this whole box with chips with the flaps tapped up. And to fit them all in I had to jump up and down on the box!!


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## Anglepoise (Jan 18, 2009)

I don't see a compound ( top slide ) or any handles.
Now I understand it's a CNC, but when you are prototyping,
how do you control tool movement?


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## precisionworks (Jan 18, 2009)

Kewl :twothumbs

You gotta love how the vector drive decreases the rpm as part circumference increases, keeping the SFPM constant.

Synthetic coolant? What brand?

Are you using a high positive aluminum specific insert?


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## cmacclel (Jan 18, 2009)

precisionworks said:


> Kewl :twothumbs
> 
> You gotta love how the vector drive decreases the rpm as part circumference increases, keeping the SFPM constant.
> 
> ...


 
I'm using Trim E206 Coolant mixed THICK at 8% the rust thing scared me  The inserts are more for Stainless and harder metals but hey USA holder and 10 name brand inserts for $35 can be beat and the finish is very nice!

Mac


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## cmacclel (Jan 18, 2009)

Anglepoise said:


> I don't see a compound ( top slide ) or any handles.
> Now I understand it's a CNC, but when you are prototyping,
> how do you control tool movement?


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## GLOCK18 (Jan 18, 2009)

Wow thats looks like alot of work, should make a real nice light.


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## PhotonFanatic (Jan 18, 2009)

Mac,

You keep putting videos up of everything, and I'll never get any work done. 

Nice machine and nice heatsinks. :twothumbs


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## cmacclel (Jan 18, 2009)

PhotonFanatic said:


> Mac,
> 
> You keep putting videos up of everything, and I'll never get any work done.
> 
> Nice machine and nice heatsinks. :twothumbs


 

Thanks Fred when are you stopping by 

Mac


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## precisionworks (Jan 18, 2009)

> The inserts are more for Stainless and harder metals


I use a high positive, aluminum specific insert, and it's the best I've found (plus the cost is low). Made by Bison/TMX, called the CNMG-432 HA H01






(click here for larger photo: http://www.latheinserts.com/images/1208911431339-1088049243.jpeg )

$54/10 inserts from http://www.latheinserts.com/product...520EF8.qscstrfrnt01?categoryId=43&productId=9

If you ever run these on your machine, you'll throw rocks at every other insert for aluminum turning.:twothumbs


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## LuxLuthor (Jan 18, 2009)

That is a cool machine. What do you do with all the cuttings? Seems like they would slice your skin pretty easily.


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## cmacclel (Jan 18, 2009)

LuxLuthor said:


> That is a cool machine. What do you do with all the cuttings? Seems like they would slice your skin pretty easily.


 

I have 2 cuts from yesterday  Pretty much toss em in a box and turn them in for scrap.


Mac


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## PhotonFanatic (Jan 18, 2009)

precisionworks said:


> I use a high positive, aluminum specific insert, and it's the best I've found (plus the cost is low). Made by Bison/TMX, called the CNMG-432 HA H01
> 
> If you ever run these on your machine, you'll throw rocks at every other insert for aluminum turning.:twothumbs



Have you ever used the Sandvik inserts made for AL? How do the Bison ones compare to the Sandvik? I know the Sandvik are more expensive, though.


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## SafetyBob (Jan 18, 2009)

Outstanding video MAC!!!! Gotta get something like that in the future. The incredible finish. 

Once again, PrecisionWorks, thank you for the link for the inserts. Would those work in any CNMG tool holder? 

Fred, if you use Sandvik, got any insert numbers so we can all take a look at them?

Bob E.


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## PhotonFanatic (Jan 19, 2009)

Bob,

The Sandvik inserts that I've used are the ones ending with a "X", so CCGX, DCGX, SCGX and TCGX. They are uncoated carbide inserts with a positive rake, but I don't recall if these are just pressed inserts, or if they are polished as the Bison inserts that Precisionworks recommends. Certainly a polished insert will provide a better finish, although it may be a bit more fragile.


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## precisionworks (Jan 19, 2009)

> Would those work in any CNMG tool holder?


They fit any holder made for a CNMG4xx insert.



> Have you ever used the Sandvik inserts made for AL?


I'm going to buy those, and the Iscar, Valenite, etc., as soon as my PowerBall number is drawn:nana:


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## cmacclel (Jan 19, 2009)

precisionworks said:


> They fit any holder made for a CNMG4xx insert.
> 
> I'm going to buy those, and the Iscar, Valenite, etc., as soon as my PowerBall number is drawn:nana:


 

LOL 

Ebay man EBAY!!

20 Sandvik Inserts and a brand new Sandvik 8" 1/2 carbide though coolant boring bar for $100!!!

Luckily without even realizing I also won a 5/8 10" Carbide bar and they both use the same inserts! So now I have 50 inserts between bars or 150 cutting edges 

The new Sandvik bar said DO NOT USE set screws.....Hmm



Mac


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## precisionworks (Jan 19, 2009)

> Ebay man EBAY!!


95+% of my tools & tooling are eBay purchased. High Positive Aluminum Inserts are rare as hen's teeth on eBay, and they aren't yet really common with lots of manufacturers. Bison/TMX sent me a free "trial pack" containing three CNMG-4xx inserts - one general purpose, one for Titanium/Super Alloys, and one for aluminum. That's how I found out that they were available in the Bison brand. Nobody has a better price on them than LatheInserts.com.


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## Anglepoise (Jan 19, 2009)

cmacclel said:


> I have 2 cuts from yesterday  Pretty much toss em in a box and turn them in for scrap.
> 
> 
> Mac



Although you have not asked for any advise, please excuse me suggesting that your chip breaker on your insets is not matched to the depth of cut and feed etc you are using. The chip breaker is close to or far away from the actual cutting edge dependant on the use of the insert for roughing or finishing. In the case of the picture you posted, the chip breaker is not in use. I am presuming that box of 'turnings' was all external. Can you imagine if the same style insert was used for boring. You would have to stop continually to sort out the tangled mess. 

I am not an insert expert but the Sandvik " Metalcutting Technical Guide"
is without question the 'bible' and is free and worth getting.


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## wquiles (Jan 19, 2009)

Nice work and nice video Mac 

Will


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## cmacclel (Jan 19, 2009)

Anglepoise said:


> Although you have not asked for any advise, please excuse me suggesting that your chip breaker on your insets is not matched to the depth of cut and feed etc you are using. The chip breaker is close to or far away from the actual cutting edge dependant on the use of the insert for roughing or finishing. In the case of the picture you posted, the chip breaker is not in use. I am presuming that box of 'turnings' was all external. Can you imagine if the same style insert was used for boring. You would have to stop continually to sort out the tangled mess.
> 
> I am not an insert expert but the Sandvik " Metalcutting Technical Guide"
> is without question the 'bible' and is free and worth getting.


 

Yes the stringy chips due pose a problem and I hope to get that sorted out some day but right now I have to much on my plate. The inserts I have are Denitool I definetly need to do some research.

Mac


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## gadget_lover (Jan 19, 2009)

If you experiment a little with the chip load by varying either the depth of cut or the speed of the carriage you will hit the point where you are breaking the chips instead of making strings. You appear to be taking light enough cuts that the aluminum is just bending as it hits the top side of the insert.

When I hit the sweet spot (spindle speed plus depth + carriage speed) there is a virtual shower of curled chips shooting off the bit, like coming from a garden hose.

Daniel


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## cmacclel (Jan 19, 2009)

In that program I was taking .050 a pass of the diameter. Looking at the insert specs my feed of 0.004 IPR was right but aluminum is recommended at 3300SFM  I was at 800SFM.

Mac


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## LED Zeppelin (Jan 19, 2009)

Those look like some mean heatsinks Mac, nice job!


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## precisionworks (Jan 19, 2009)

> but aluminum is recommended at 3300SFM


It's hard to run too fast in aluminum ... the Bison catalog recommends running their high positive insert at 900 - 2700 SFPM, DOC between .030 - .160, IPR between .004 - .016 .

If you have a close focus binocular or spotting scope, watch the curl as it hits the cutting edge & starts forming the helix. When speed, feed & depth are correct, the helix will get only 1/2" to 1" long, then start flopping like a dying fish, then break off. (Don't be tempted to stick you head in close too the chuck, especially with CNC, which is the reason for the binocs or scope :sick2: )

Chip flow varies with DOC, using nose radius as a guide. The following is from the Bison Catalog, page 160

When the depth of cut is less than nose radius
• Depth of cut 0.020~0.060 inch, finish or medium-finish cut.
• Main chipbreaker breaks the chip and sub finish chipbreaker controls chip flow.

When the depth of cut is equal to nose radius
• Depth of cut 0.031~0.080 inch, medium-finish cut.
• Main and sub chipbreaker break the chip.

When the depth of cut is 2~4 times the nose radius
• Depth of cut 0.06~0.18 inch, medium cut.
• Rough chipbreaker breaks the chip.

When the depth of cut is 5~8 times the nose radius
• Depth of cut 0.16~0.235 inch, medium-rough cutting range.
• Side of rough chipbreaker breaks the chip.


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## wquiles (Jan 19, 2009)

precisionworks said:


> It's hard to run too fast in aluminum ... the Bison catalog recommends running their high positive insert at 900 - 2700 SFPM, DOC between .030 - .160, IPR between .004 - .016 .
> 
> If you have a close focus binocular or spotting scope, watch the curl as it hits the cutting edge & starts forming the helix. When speed, feed & depth are correct, the helix will get only 1/2" to 1" long, then start flopping like a dying fish, then break off. (Don't be tempted to stick you head in close too the chuck, especially with CNC, which is the reason for the binocs or scope :sick2: )
> 
> Chip flow varies with DOC, using nose radius as a guide.






gadget_lover said:


> If you experiment a little with the chip load by varying either the depth of cut or the speed of the carriage you will hit the point where you are breaking the chips instead of making strings. You appear to be taking light enough cuts that the aluminum is just bending as it hits the top side of the insert.
> 
> When I hit the sweet spot (spindle speed plus depth + carriage speed) there is a virtual shower of curled chips shooting off the bit, like coming from a garden hose.
> 
> Daniel




If I am reading this right, you guys are saying that making the strings is "bad"? Or just not "optimum"? Can you please expand this more?



Will


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## QtrHorse (Jan 19, 2009)

I have always heard chips are best for aluminum but I have never ran a CNC/ lathe. I am only familiar with a automated table router.


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## gadget_lover (Jan 19, 2009)

wquiles said:


> If I am reading this right, you guys are saying that making the strings is "bad"? Or just not "optimum"? Can you please expand this more?
> 
> 
> 
> Will





Please don't take my word for it, but here's my understanding.

Metal machining (lathe or mill) has been described as controlled breakage of the metal through the formation of chips. I saw a great video that showed how the chip was formed, how the metal it is fractured rather than cut.

If see ribbons, you are not cutting as aggressively as possible. The chip does not fracture completely and thus forms a string.

Are strings bad? They can be. When they curl around the work, they can damage (scuff) the freshly turned surface. When they spin with the work they can catch the pile of strings that have built up and send swarf everywhere. They are often sharp as razors and can catch a finger when you absentmindedly try to sweep one away.


But don't take my work for it.


Daniel


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## cmacclel (Jan 19, 2009)

Daniel so basically your stating turn the feed rate up until you get chips and not strings? That would have been scary with a 4lb chuck of aluminum I was holding by a 1" .500 stub 

When I have the time I really need to try some things to get rid of the swarf! Any reading materials you thing would be helpful would be appreciated.

Thanks Mac


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## 65535 (Jan 19, 2009)

cmacclel said:


> Daniel so basically your stating turn the feed rate up until you get chips and not strings? That would have been scary with a 4lb chuck of aluminum I was holding by a 1" .500 stub
> 
> When I have the time I really need to try some things to get rid of the swarf! Any reading materials you thing would be helpful would be appreciated.
> 
> Thanks Mac



That's why you got that honkin 6 Jaw chuck.


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## cmacclel (Jan 19, 2009)

65535 said:


> That's why you got that honkin 6 Jaw chuck.


 

Your three jaws ahead of yourself there 

Mac


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## 65535 (Jan 19, 2009)

Duh, with so many 6 Jaw chuck posts I thought one of them was yours. I suppose you probably can't push a live center up against the face either huh.


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## wquiles (Jan 19, 2009)

cmacclel said:


> Your three jaws ahead of yourself there
> 
> Mac



He is probably thinking about this one, with the "extra" 3-jaws :devil:













Will


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## 65535 (Jan 20, 2009)

What do you mean "extra" he's missing 3 haha.


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## gadget_lover (Jan 20, 2009)

cmacclel said:


> Daniel so basically your stating turn the feed rate up until you get chips and not strings? That would have been scary with a 4lb chuck of aluminum I was holding by a 1" .500 stub
> 
> When I have the time I really need to try some things to get rid of the swarf! Any reading materials you thing would be helpful would be appreciated.
> 
> Thanks Mac




Since you are on the low end of the IPR, you might try increasing that to mid range. Deeper cut or faster IPR both have the same impact on chip breaking. It's not like you have a wimpy lathe  

I have dozens and dozens of machining related links... figuring out which one had that info is hard to say. Of course, I also read the first 3/4 (1,500 pages???) of "Machinery's Handbook" over the course of several months, so I may have seen it in there. You check there and I'l check the web. Let me know if you find it. 

Seriously, I'll see if I can find it.

Daniel


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## precisionworks (Jan 20, 2009)

> you guys are saying that making the strings is "bad"? Or just not "optimum"?


Long, continuous curls, which can go twenty feet or more in some materials, are a real hazard to the operator. If one wraps around your finger, the amputation will be a surgeon's nightmare

They usually foul the cutter, when the chip tries to pass under the tip while the tip is pressed into the work, and can really screw up a finish cut where you want to take less than .005 off the diameter. On internal cuts (threading, boring, facing, etc.) they will again foul the cutter, although sometimes high pressure air will assist with evacuating the chips.

We ran lots of LaSalle 1144 Stressproof at the mine repair shop. When you were in the zone, chips would come off cobalt blue, about an inch long, and fly exactly the distance & trajectory to hit the operator (me) at the next lathe I don't think my boss did that intentionally, or at least I never could prove it.

Short chip coils generally mean the correct insert type/grade/chipbreaker, plus correct DOC, feed, and speed. On some materials, like HDPE plastic, the chips will not break, no matter what, and heavy weldging gloves + a big pair of Channelocks are needed to pull the string out of the way.

*Don't ever wear gloves around machinery.*


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## wquiles (Jan 20, 2009)

precisionworks said:


> Long, continuous curls, which can go twenty feet or more in some materials, are a real hazard to the operator. If one wraps around your finger, the amputation will be a surgeon's nightmare
> 
> They usually foul the cutter, when the chip tries to pass under the tip while the tip is pressed into the work, and can really screw up a finish cut where you want to take less than .005 off the diameter. On internal cuts (threading, boring, facing, etc.) they will again foul the cutter, although sometimes high pressure air will assist with evacuating the chips.
> 
> ...



So Barry, if I am getting long curls (which happens often to me!), I need to make a deeper cut and/or increase the spindle speed until I get chips or shorter curls?

Will


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## 65535 (Jan 20, 2009)

I'd say that strings aren't inherently bad in regards to your technique, but like percisionworks said they can become a hazard.

Aluminum is one of the more stringy metal, if you do a lot of shallow cuts you probably want to look into an aggressive chip breaker.

IIRC there may be a bolt on type of chip breaker that has an arm directly above the tooling that fractures the string as it comes off.


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## precisionworks (Jan 20, 2009)

Will,

Each manufacturer will show the recommended DOC, IPR, & SFPM for a particular insert.

DOC determines chip thickness ... if you set DOC at .050, you can measure chip thickness at (close to) .050.

IPR determines chip width ... slow feed gives a narrow chip, fast feed gives a wider chip.

SFPM determines how cool or how hot the chip is. In ferrous metals like mild steel, the chip should peel tan or brown, and turn blue as it drops. No color indicates too slow, red indicates too fast.

Chipbreaker design - every maker has their own proprietary design for each specific material. Chipbreakers are dramatically different for Ti, SS, aluminum, etc.



> I need to make a deeper cut and/or increase the spindle speed until I get chips or shorter curls?


As you see, there are so many variables that just going to more DOC, or higher RPM, may or may not give the best result.


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## cmacclel (Jan 20, 2009)

The Denitool inserts I have give no DOC, only IPR and SFPM.

Mac


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## Fred S (Jan 20, 2009)

as far a chips, I would go with a higher feedrate (at least on roughing cuts). The add-on chipbreaker would help also. They usually just go on top of your insert and screw or clamp down.


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## precisionworks (Jan 20, 2009)

> The Denitool inserts I have give no DOC


With a rigid spindle, enough hp, and a strongly shaped insert (nothing really pointy), you can go pretty deep. When we ran the CNMG-532 Iscar on a 25 hp spindle, it was nothing to set the DOC at .250


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