Aluminum Heat Dissipator plates now available

[mhackney]

Thanks Gene. I could make them on my CNC mill but the labor costs would be too high to make more than a few. I typically make prototypes and small production runs myself and then when I see there is a market/opportunity work with a local shop to scale. Waterjet is an amazing technology and I get 1000s of .032", .065" and .125" brass and aluminum parts cut a year. These are all about 3" D or less. So any issues with stress release do not show up, that's why I didn't think to ask the machinist. Thicker parts work fine but they are more expensive and I will take longer to heat up due to the extra mass.

I can cut .125" ally on my mill at full depth and 25 in/min but only 1 at a time. Its the material handling that adds up!

[barnett]

Made this a few days ago to test my z height and delta radius. It's not perfect, but it all stuck to the glass except a few spots near 11 o'clock.

I think my plate is probably fine.

[cambo3d]

doing that on top with the glass wont give you accurate idea of how flat your aluminum plate is, but if your printing with it like that, that's fine, because your calibrating it to the glass.

the glass will mask some of the discrepancies of the aluminum plate. (if you have any)

[barnett]

Yeah but all I care about is printing on the glass. If I can print to the whole surface, then I'm happy. I'm open to suggestions on how to further improve it - such as playing with the location of the clips.

Thanks.

[ichiban]

why not just cnc mill the plates? It would require no second operation other than maybe some deburring. Also, I really think the way the heater is fixtured is the problem. 3 points define a plane, and usually a locating pin, a slot and a loose through hole is the best way to define a plane that will see heat expansion. I'm trying to bring an older cnc mill up and operational, after that I will try milling out a thicker (1/4") heat spreader.

[mrbi11]

You do need to insulate a few exposed traces on the Onyx. And if you accidentally scratched yours, you will need to insulate that area too.

Backs Side.jpg

Kapton tape over the connector's solder area too perhaps?

[CJGerard]

I have never heard of a water jet stressing aluminum and causing warping before and i ran one for quite awhile making aerospace parts. Lasers on the other hand have been known to do just that. Stamping would probably be the best method of making the plates since it would smash or "coin" the material flat. Cast plate would be another option.

I am wandering if the warping was cause by the counter sinks or holes for the flat head screws being slightly off location? Over tightening the screws would probably lead to something similar. Or even getting damaged in the mail?

Anyway I really liked how you matched the build plate up with the oynx and i don't think you should stop making them. Maybe test a few without the holes (use binder clamps) and machine them by stacking them up to reduce run-time?

I machined 4 aluminum build plates this way Wednesday night before i left work and it went pretty quick. (just 12" circles that are held to the oynx by the binder clamps) I tested one of them last night and although it takes 10 min to reach 90c it holds the temperature really well and it dissipates the heat more evenly.

[mrbi11]

I found a place that will do a round plasma cut on 1/4 inch plate.
I recommend material #6061 for stiffness.
Edges were rough, but I'd say 1/16 variation. He said 1/8
Surfaces were smooth, and 12" exactly fit the heating bed.

I am not affiliated with the seller, just thought someone else might have trouble finding round plate the right size.
I found tons of square cut pieces, only this place would do round for a reasonable price.

They had a $60 minimum, so i bought 2 at $40 each.
They had some volume discounts, see email below.
Shipping was $16 for me, but depends on where you are i suppose.

You need to bevel or cut the part over the 12v solder connections!!!
And add Kapstan tape to insulate both pieces at the solder points.

His email quote is below.

======
2 pcs would be $40/ea, which includes labor and material.

10 pcs - $35/ea

20 pcs - $30/ea

50 pcs - $25/ea

Jason Merrell
Texas Inside Sales
Discount Steel, Inc.
10353 Hicks Field Rd
Ft Worth, TX 76179
T (682) 730-3008
F (682) 286-9925
discountsteel.com

[bubbasnow]

I found a place that will do a round plasma cut on 1/4 inch plate.
I recommend material #6061 for stiffness.
Edges were rough, but I'd say 1/16 variation. He said 1/8
Surfaces were smooth, and 12" exactly fit the heating bed.

I am not affiliated with the seller, just thought someone else might have trouble finding round plate the right size.
I found tons of square cut pieces, only this place would do round for a reasonable price.

They had a $60 minimum, so i bought 2 at $40 each.
They had some volume discounts, see email below.
Shipping was $16 for me, but depends on where you are i suppose.

You need to bevel or cut the part over the 12v solder connections!!!
And add Kapstan tape to insulate both pieces at the solder points.

His email quote is below.

======
2 pcs would be $40/ea, which includes labor and material.

10 pcs - $35/ea

20 pcs - $30/ea

50 pcs - $25/ea

Jason Merrell
Texas Inside Sales
Discount Steel, Inc.
10353 Hicks Field Rd
Ft Worth, TX 76179
T (682) 730-3008
F (682) 286-9925
discountsteel.com

how is this working?

[mrbi11]

They plate works perfectly.

1) it will slow down heating up the bed, so plan ahead , use the preheat function on 1st menu of lcd
--or maybe take it off for small prints, but then you have to re calibrate for zero.

2) Make sure the heater bed has kaptan over the pass thru's (I'm told) and the solder points -more obvious.

3) I ground the edge down that goes over the solder points, so nothing is pushing the kaptan, and put a second layer of
kaptan on the ground part of the plate, which also reminds me that part goes over the solder points.

Good luck.

[bubbasnow]

Did you have them drill the holes for the screws?

[mrbi11]

No, I just set it on top of the heater. I had to get some larger clips to hold the glass down, and they also hold the aluminum.

It would be pretty easy to use the insulator that hols up the heater plate or the plate itself as a template to mark drill holes if you feel you want them.
I could not see any reason to drill it.

[mhackney]

CJGerard, I checked around and this warping is a known issue with certain Al alloys in thinner thicknesses.

12" disks would work fine if you simply clamp the sandwich of glass and Al down but does not leave enough room around the perimeter for screw holes. I was also attempting to eliminate the bowing from the Onyx as it heats up. I did lots of tests and measurements and the Onyx bows significantly when heated. The original thought was to use the Al disk to clamp it down as well as dissipate heat. The 12-3/16" disks I was making added to materials cost since stock is cut to 12" increments. I ended up with a fair amount of waste cutting from 4'x8' sheets of Al.

I am using a 24V power supply to the Onyx now and I heat the bed to 80°C in less than 2 minutes. It gets to temperature at about the same time as my hot end, so I'm ready to print pretty quick!

If you are simply clamping the Al with binder clamps, why use such thick aluminum plate? If you are going to put borosilicate over the top, I'd recommend using a thinner Al plate, even 1/16", and simply clamp the stack with the binder clamps. I think most people are not observing the warping Onyx because they have the borosilicate clamped to it and it might be minimizing the warping. Adding a thin Al disk will dissipate the heat effectively and not take as long to heat up. I think I am going to reinvestigate this and maybe manufacture these modified 12", thin Al heat dissipators (after doing a lot of testing). I can CNC mill these on my equipment too so would eliminate the warping I experienced with waterjet.

Cheers,
Michael

I have never heard of a water jet stressing aluminum and causing warping before and i ran one for quite awhile making aerospace parts. Lasers on the other hand have been known to do just that. Stamping would probably be the best method of making the plates since it would smash or "coin" the material flat. Cast plate would be another option.

I am wandering if the warping was cause by the counter sinks or holes for the flat head screws being slightly off location? Over tightening the screws would probably lead to something similar. Or even getting damaged in the mail?

Anyway I really liked how you matched the build plate up with the oynx and i don't think you should stop making them. Maybe test a few without the holes (use binder clamps) and machine them by stacking them up to reduce run-time?

I machined 4 aluminum build plates this way Wednesday night before i left work and it went pretty quick. (just 12" circles that are held to the oynx by the binder clamps) I tested one of them last night and although it takes 10 min to reach 90c it holds the temperature really well and it dissipates the heat more evenly.

[mrbi11]

CJGerard, I checked around and this warping is a known issue with certain Al alloys in thinner thicknesses.

If you are simply clamping the Al with binder clamps, why use such thick aluminum plate?
If you are going to put borosilicate over the top, I'd recommend using a thinner Al plate, even 1/16", and simply clamp the stack with the binder clamps.

---

Cheers,
Michael

I used 1/4 inch because others said it worked. I still get about 5 degree drop center to edge. Much better than 50 degree drop!
My guess is a thinner plate may get less even temperature.
For one or two, the material cost is much less than the cost of a round cut, so thinner would not save anything.
I bought 2 because the minimum shop charge was $60 and 1 was $40.

I use binder clips to hold the glass 1/4 inch plate and heater bed together.
I had to move up from smallest clips to medium clips.

I get about .1 to .2 height difference between cold and hot beds, and cannot detect any shape change due to temperature.
Your mileage may vary

-B

ps- do i understand correctly you have a cnc machine to mill aluminum? Do you sell pieces milled to order?
Please send me a private message if so of how to contact you off board.

[mhackney]

Interesting, I wonder if the thicker plate is also dissipating heat at the edges faster? My plate is within 1°C across the entire surface - 1/8" plate. maybe the 1/4" edge is radiating the heat from the periphery.

Actually, the material cost was the bulk of the price when I was manufacturing these. The labor to cut was low in quantities of 25. The 1/4" stock was more than 2x the cost of 1/8".

I have a complete shop with two CNC mills and a CNC lathe. You can contact me at mhackney - at - eclecticangler.com

Cheers,
Michael

[mrbi11]

Honestly I am not that sure of the temp measurement. I used an IR gun type, and used it on the glass.
When I pointed it at the bare shiny aluminum it read room temperature-ish. Science thing i guess.

I have an accurate thermo-meter for it, but no reason to go to the extra trouble.

The edges of mine are very rough cut, so could also be radiating faster than the shiny finish.

My 1/8 inch cheap frying pans distribute heat great, so I have no reason to think thickness is an issue.
I did try 1 sheet of aluminum foil under the glass, and got no measurable improvement over the bare heater bed.

I look forward to seeing how your new plates do!

[enggmaug]

I always heard of al plates, but never of copper plates... why is that ?
Is it about the price, or is copper warping too much, or too hard to mill, or just not relevant enough ?

I don't have any knowledge in engineering metal, but in school, I learned that copper will conduct heat better and faster than Aluminium, so a thinner copper plate could have the same dissipation effect as a larger Aluminium plate, without being too long to heat up...

Am I wrong ?

[geneb]

Have you priced Copper lately?

g.

[Eaglezsoar]

I always heard of al plates, but never of copper plates... why is that ?
Is it about the price, or is copper warping too much, or too hard to mill, or just not relevant enough ?

I don't have any knowledge in engineering metal, but in school, I learned that copper will conduct heat better and faster than Aluminium, so a thinner copper plate could have the same dissipation effect as a larger Aluminium plate, without being too long to heat up...

Am I wrong ?

You are not wrong. Copper does conduct heat faster the problem with copper is the same as all the metals, it warps as heat is applied. I am not a metals expert but I do know that
copper will expand and contract based on temperature, the thinner the metal the more this "warpage" would be noticeable. I would rather use copper but I just did a quick look-up
and a square foot 1/4" piece is approximately $200, I did not find a round piece. So you are right but the cost is prohibitive and you would want something at least 1/8" thick and
my preference would be 1/4". If I could find a round piece big enough to fit the Rostock Max I would buy it over aluminum if I had the funds.

[mhackney]

Cu conducts heat and electricity much better than aluminum. And it is MUCH more expensive. It also is much softer and easily bent in even thin cross sections. The thickness does not have a big impact on the heat dissipation across the surface. I did a LOT of testing on heat dissipation last year. I tested very thin .062" aluminum and it conducts heat very well and creates an evenly heated surface. It also takes much less time to heat up. I chose to use 1/8" Al in the plates I made because my intent was to create a dead flat surface - one of the issues with the Onyx and all heated beds like it - is that it warps when heated. If you just want a dissipating plate and intend to put glass on top, a 12" disk of .062 aluminum will server very well and should be inexpensive.

[Eaglezsoar]

Cu conducts heat and electricity much better than aluminum. And it is MUCH more expensive. It also is much softer and easily bent in even thin cross sections. The thickness does not have a big impact on the heat dissipation across the surface. I did a LOT of testing on heat dissipation last year. I tested very thin .062" aluminum and it conducts heat very well and creates an evenly heated surface. It also takes much less time to heat up. I chose to use 1/8" Al in the plates I made because my intent was to create a dead flat surface - one of the issues with the Onyx and all heated beds like it - is that it warps when heated. If you just want a dissipating plate and intend to put glass on top, a 12" disk of .062 aluminum will server very well and should be inexpensive.

Michael, I remember the thinner plates that were sent out and ended up warping because of the way they were cut with a water jet. In your opinion then it is not the heat from the Onyx that can make the plate warp? In other words, if you start out with a straight plate it should remain straight used in this application or will the warping of the Onyx transfer itself to the
aluminum plate?

[enggmaug]

oops, I knew Cu was indeed more expensive than Al, but I did not think it could be THAT expensive...

Thanks for all the info.

[mhackney]

Eagle, my experience was that if you had a flat aluminum plate (my 1/8" ones) it would indeed keep the Onyx flat. These plates were screwed down at the same 6 locations as the Onyx and constrained it from warping upward. Mine has been dead flat since I installed it. But, mine was not water jet cut. None of the first batch that were water jet cut required returning. Whereas most of the water jet ones either arrived warped or warped shortly thereafter. Talking to the shop and materials supplier, this is not unheard of. The water jet can stress the aluminum, especially thin sheets like I used, that can relieve and warp later. Every dissipator I shipped was flat when it left my shop, I checked each and every one of them.

For those of you who are new, I offered these plates for sale last year. When this problem arose, I refunded - INCLUDING shipping costs - anyone who had an issue. I took a bath on it, but it's the way I do business.

Regards,
Michael

[bubbasnow]

so my MIC 6 will be in this week, i found a place with waterjet to cut it... should i reconsider and go with a cnc cut? its 1/4 thick

[mhackney]

1/4" should be fine and MIC 6 is stress relieved before it is ground. Ask your shop, they will know for sure.