So I think for the build I will be changing it to fit in a Solarforce host. I like the Dorpmuller, Itinifni/ Vinz look of a P-60 in copper. Where to score 3/4 slugs of copper or a 3/4” rod cut down to 5mm slugs? I could get discs on Etsy and solder them together but that costs about as much as a 12” rod of 3/4” copper at onlinemetals web site.
I recently ordered some aluminum rod from Exact Metals on eBay. When the product arrived it came with a flier that said to contact them by phone or email for cut to size stuff. I don’t see copper in their eBay listing, but the flier did say all types of metal in full lengths ready to cut.
7/8” copper fit’s loose in a Solarforce head, I used a piece 1” long to put the triple Noctigon on. Wanted it to be closer to a press fit, but didn’t want to pay for the 1” and then turn 3/32” of it into dust.
onlinemetals.com is supposed to be offering USPS shipping to save on that shipping cost, but I haven’t noticed em doing it yet. UPS from them is just ridiculous! Check em out, if they don’t have it yet as an option throw a fit, maybe we’ll get it affordable to get small pieces yet!
(A small flat rate box is only $5.05 shipped anywhere in the US in 2 days, if it fits, it ships. They have a pound limit on that {forget what it is}but to get a 3” long bar of 1” copper would be sweet at $5 shipping)
I have never really found a good cheap source for copper. I usually just stroll around ebay until I find something reasonable.
If your looking for aluminum, the best place I have found is http://www.stockcarsteel.com/aluminum-round-bar/6061-aluminum-round-bar
I have ordered several times from them, the shipping charges and the per a foot price are a lot less than others I have found. If you make the phone call they should also ship the items usps for a reduced cost, if you ask.
They do send out 10% off coupons about every month it seems to my email box. Might try searching for one for a even sweeter deal.
Pre 1982 cents are brass, not copper. Brass has a conductivity of around 100. Aluminum is twice as good. Real copper is 4 times as good.
Argh! Well. Sheesh. Even the penny was wrong. Only direction is up from here. I guess I’m going to have to fall back to a variation of the Dorpmuller and Itinifni P-60 builds. The Itinifni use of a copper pipe/sleeve helped him get a good fit but I don’t intend on using the AA or brass pill bottom. Both appear pretty straight forward. I also would like to do the FET on a 105c trick as that just sounds explosively cool, but I’m not sure where exactly to put it. I need to see a picture as some of the descriptions on other threads probably make sense to people that can identify the parts of an IC. (Not me)
95% copper is technically 'brass', and I imagine under some unrealistic extreme tests you could find a measurable difference between 'brass' with 95% copper and C101/C110, but I doubt it would translate into anything meaningful in real-world applications.
FET is mounted upside down here, with the legs straightened out and then re-bent the opposite way to touch the PCB. In this pic, the outer leg is ground, inner leg is the gate (the PWM input from the MCU), and the black LED- wire attaches to the big metal pad on the upper surface of the FET (wire not shown in the pic).
I thought pennies had to be 1964 or older to be mostly copper? I will go look that up. I am no coin expert! lol
You might be surprised… even tiny changes in a material can radically affect it’s thermal conductivity. Thermal conductivity does not change linearly with to the ratio of the materials in the mix. For instance, pnly a few parts per thousand of phosphorus in a copper alloy will utterly kill its thermal conductivity.
On the other hand there are many different varieties of brass, ranging from 65% copper to 95% (pre-1982 pennies are 95%). I doubt all the varieties of brass have the same thermal properties.
EDIT: Found it:
Gilding Brass (95% copper). Looks like it has 60% of the thermal conductivity of pure copper.
Comfychair, that’s perfect! Thanks. The diagram is a huge help.
Are you set up to flash driver firmware? I don't know if any stock drivers will run the FET correctly, it has to use firmware written for the 9.4kHz 'phase-correct' PWM.
Hey, that's MY line!
So, like-for like test. 16mm copper MCPCB on a filed-down pre-'83 brass penny, 16mm copper MCPCB on an identical size/thickness C101 (or whatever) copper disc. Same power to both. How many lumens difference between these two materials with vastly different thermal properties?
I'm going to be bold, and predict the difference will be within the margin of error for the measuring equipment. :~
Comfychair, that’s perfect! Thanks. The diagram is a huge help. I think I can use the driver that I broke to make this work. Which would be kinda funny. Thanks.
I thought I posted this before, I used comfy’s diagram and it worked ’til I put it in the pill and pulled off the positive via completely. So I desoldered it and in the process nicked off a little chip that RMM carefully put on the spring side of the board. Never found the piece/chip.
You might want to elaborate a little… most of us probably have a rusty memory of this thread by now.
I’m assuming that you’d like to know what the missing part was so that you can get another part and put that in it’s place.
If Im not confused, hes taking some crack for back pain too so he might be less than coherent anyway lol. But I could have him confused with someone else.
The Composition of the Cent
Following is a brief chronology of the metal composition of the cent coin (penny):
• The composition was pure copper from 1793 to 1837.
• From 1837 to 1857, the cent was made of bronze (95 percent copper, and five percent tin and zinc).
• From 1857, the cent was 88 percent copper and 12 percent nickel, giving the coin a whitish appearance.
• The cent was again bronze (95 percent copper, and five percent tin and zinc) from 1864 to 1962.
(Note: In 1943, the coin’s composition was changed to zinc-coated steel. This change was only for the year 1943 and was due to the critical use of copper for the war effort. However, a limited number of copper pennies were minted that year. You can read more about the rare, collectible 1943 copper penny in “What’s So Special about the 1943 Copper Penny.”)
• In 1962, the cent’s tin content, which was quite small, was removed. That made the metal composition of the cent 95 percent copper and 5 percent zinc.
• The alloy remained 95 percent copper and 5 percent zinc until 1982, when the composition was changed to 97.5 percent zinc and 2.5 percent copper (copper-plated zinc). Cents of both compositions appeared in that year.
Thanks for the link Scotty, old or not, a fun read. Only can add that OL mentioned using hardware copper pipe and plugs when doing custom work. No idea about purity but would not be surprised if Lowes mixed the copper for max profit.
Still deciding on which host to use to avoid welding glove option 
Yup, narcotic addled mind is in full effect. Back still hurts but I can attain otherwise comfortable positions. The driver that I tortured is in an empty cocoa tin waiting to donate parts to other future builds. I was just barely able to resist pulverizing it with a hammer. My reasoning at the time was that everything I did with that driver was so pathetic that should my skill or luck continue and I took a hammer to it I would likely zing a fragment into my eye and lose the eye. So, nope not looking to fix it. I just replaced it with a FET Zener driver from RMM’s site. It’s a ferocious and ludicrous hand grenade of light. After 60 seconds it should step down from turbo and it very well might but it gets way the hell too hot to hold long before that. The element of danger makes it more cool, sorta.