# Looking for someone to help me make heatsinks



## LEDcandle (Jan 22, 2006)

Actually just need one specific alu or copper heatsink for a project-light I am about to work on but I'm thinking maybe I could just buy a small block of alu or copper and get a few different sizes of heatsinks done to make it more worth it for everyone.

I'm hoping its reasonably priced for the material and workmanship. They will most probably be mostly the typical, simple round pieces of metal, just in different sizes. I believe the sinks should be able to fit a GPM small envelope, shipped to Singapore. 

Pls post here or PM me for more details. If there are multiple takers for this small 'job', I'm pretty much willing to take the first person that comes along as I believe everyone's reasonable , unless I find it unreasonably expensive or something, then maybe I'd have to get a few quotes. Can pay by paypal cash.

Hope someone can help me! :candle:


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## scott.cr (Jan 22, 2006)

Ya have any drawings? They don't have to be fancy... but they'd have to be within the realm of the home machinist (for me at least).


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## LEDcandle (Jan 22, 2006)

Hi scott, I'll try to get some photos and drawings up later.
Am still thinking of how the heatsink should look and what other pieces I might need


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## Morelite (Jan 22, 2006)

I can help out also. I have some 1" round stock in aluminum, copper, and brass.


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## LEDcandle (Jan 22, 2006)

--- double post----


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## LEDcandle (Jan 22, 2006)

Cool, I'll just post my stuff up when I get off from work later and we'll see who best can help me out. I guess as said in my first post, I'll give scott priority if he can take up the job at a reasonable price 

If this thing turns out to be a 'tender exercise', as in more people come in offering good prices or a better method etc, I might have to go with the one I feel is the best fit for me. 

Thanks a lot guys, don't like to go through all these monetary details.. phewf...


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## scott.cr (Jan 23, 2006)

I'm not vying for your money or anything... just looking for a good project. Maybe stimulate some activity on the board.

I'm in the middle of two projects right now, a Mag85 (2D host) and a Luxeon III Mag 2C. Since I'm new here, my finished product will be a bit different than the norm since I'm designing from a different angle than most of the old-timers here.


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## LEDcandle (Jan 23, 2006)

I know scott, that's why I say I don't like talking about money 

Just trying to make things clear from the start. My seeking help here is totally non-commercial too... just need a favour from someone who can help me with my mod plans.


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## LEDcandle (Jan 23, 2006)

This is the host :-






This is what I had in mind :-










I'm not a technical expert so pardon my poor drawings. I don't have the exact dimensions yet but this is the rough idea.

Basically, the main heatsink is composed of a neck and disc. The neck is to mount the luxeon at the right height within the reflector and the disc area is to sink the heat. I might need to adjust the height of the luxeon within the reflector, so I guess the neck can be shorter than necc and I will need some 'buttons' (just small round pcs of alu/copper) to adjust the height. 

2 holes need to be drilled in the neck for the wires. 

The convertor holder is just another piece of metal which can house my convertor (of which the positive contact point is at the bottom). I will stick it to the heatsink after everything is in place (see the wireframe).

I also thought if its possible, to have the disc of the heatsink 'finned' (pic only shows a few fins, I thought of the fins going round the entire disc) for better dissipation.

Sorry if I'm not clear about anything. Pls feel free to ask me anything. Any thoughts? Is this a complex job?

Thanks!


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## scott.cr (Jan 23, 2006)

This is not a difficult machining job per se, but the heatsink could be redesigned to minimize material waste. You might consider making it (the converter and heatsink) one piece if doing so would be possible and still allow it to fit your light.

The converter holder would be a snap. The heatsink however would entail removing a lot of material from solid round rod. If you can imagine how a lathe works, you can imagine starting with a piece of large-OD round rod and then turning it down until you get that small LED mounting post. Round rod with that large of an OD is expensive. (Remember the area of a circle is pi * R^2, so increasing the OD of your material from 25mm to 50mm increases the material quantity and cost by a factor of four.) If you look at the design of the Hotlips, you can see it is a very simple device that concentrically mounts a Luxeon emitter and requires very little machine work.

You will also have to determine the height of the LED. You can do that by temporarily mounting it on a wood dowel and sliding it back and forth in the reflector until it makes a beam you like. Then record the measurement. AFAIK, everyone mounts Luxeon emitters right at the base of parabolic reflectors.

Oh, about the fins on the heatsink. They can be cut like you have in the drawing but they will be in the shape of a pie slice. I don't know offhand how to machine them into straight fingers; perhaps someone else on the board would know.


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## greenLED (Jan 23, 2006)

you'll have to lower the Lux, it's waaay off the focal point for that reflector. The die has to be slightly above the bottom of the reflector, IIRC - don't have measurements, sorry.


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## wquiles (Jan 23, 2006)

scott.cr said:


> You will also have to determine the height of the LED. You can do that by temporarily mounting it on a wood dowel and sliding it back and forth in the reflector until it makes a beam you like. Then record the measurement. AFAIK, everyone mounts Luxeon emitters right at the base of parabolic reflectors.


That has always been one of my biggest questions regarding the Turbo LED modules since at least visually to me, it appears not to be at the parabolic base, but rather just above it, at the same height as a regular incandecent bulb :thinking: 

Will


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## gadget_lover (Jan 23, 2006)

scott.cr said:


> Oh, about the fins on the heatsink. They can be cut like you have in the drawing but they will be in the shape of a pie slice. I don't know offhand how to machine them into straight fingers; perhaps someone else on the board would know.



Straight fingers are cut by mounting the piece in a rotary table or chuck and offsetting the cutter to the left and then right to make the cuts, then rotate and cut again. A similar example is "cutting spokes". 

Daniel


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## pbarrette (Jan 23, 2006)

Hi all,

I agree that a 1 piece solution would be a lot easier.

However, my main problem with the current design is that the host seems to be a plastic body with no metal contact to the air. As such, any heatsink you put in the light will only work for a couple of minutes at best.

Fins on the heatsink will actually make this design worse. Since the "heatsink" will be completely enclosed in an insulating container, the proper approach would be to stick as much solid aluminum in there as possible. The aluminum will then be a large solid mass that will take more time to heat up. A finned design would remove that needed mass and be wholly useless since there is nowhere for the heat to dissipate out to.

In my opinion, the large disk pictured would need to be at least 5 times as thick or more just to achieve reasonable heatsinking for anything more than 1 or 2 minutes of runtime.

pb


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## LEDcandle (Jan 23, 2006)

Thanks for the great comments guys!!

*Scott :* You got a point on material waste and stuff. I wasn't really thinking of that but just trying to get the idea across. If you have better suggestions that's cool  Perhaps the 'neck' could be separate piece. Sorta like cutting a piece from a 10mm stock for the neck (for e.g, dun know the dimensions yet) to be mounted on a 2 inch stock cut into a disc shape. I'd still need the neck to be hollowed out on one end and the 2 holes drilled, and a hole to be bored in the centre of the disc. I don't know what sizes the alu stock comes in, so I guess it'll have to be machined accordingly.

The contact won't be as good as a sold piece, but it might be cheaper than grabbing a solid block and fashioning that neck. What do you suggest?

In my original drawing, my intention was to insert the convertor into the convertor-holder through the top, and stick it with adhesive to the "lip" at the bottom. If you can make the entire heatsink/holder in 1 piece, the convertor will have to be fitted from the bottom. This is good but I would need to get the exact dimensions and I don't have an electronic vernier caliper. The convertor would need to fit snugly into the shaft and I could then probably apply adhesive to the sides. Feel free to comment 

*greenLED :* As will was saying, I have a turbo module LED and it's not mounted at the base but instead at the height of the previous incan bulb. So I'm thinking the correct height would be exactly where the old incan bulb filament was. I would have to test this first, but I'm not sure the base is the right place. For mags, it seems to work fine at the base though because the old bulb was low too? :thinking:

edit : ok, my light looks like the bulb is at the base too. I prob would need only a VERY short neck to hold the luxeon at the base. A button stuck on a disc does sound like a better idea than a whole piece fashioned out just for the neck. 

*pbarettep* : Yeah, I was really concerned about heat. I might run a Downboy 500 or less in there if necessary. The Luxeon is a U-bin, so I think I'll still squeeze out a decent amt of lumens at below 750ma drive. 

The solid block sounds like a better idea. Fins are usually better only if there's a fan blowing at it. I have another luxeon star mod thrown in a plastic flashlight, with a bunch of 8 coins stuck behind the star. It gets hot pretty fast (stuck a thermometer probe on the star), but around 10 mins to reach 70 degrees. The mod is direct drive, and once the batt falls to about 3.7v, the temps are manageable. 

I think if I run a low ma Downboy, and with the chunk of alu in there, it might be able to work. I just ordered an infrared thermometer too, and will be able to run some tests on it (though that would only be AFTER I've spent money to make the heatsink..hahaha  )


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## LEDcandle (Jan 23, 2006)

How about something like that instead?





Basically, a small button to mount the lux at the base of the reflector, adhered to a larger disc (1) which is adhered to another button and adhered to a final disc (2). 2 holes drilled in between this 'sandwich' for the wires. Should the discs touch the flashlight body? Although its plastic, it prob still transfers better than air. 

Convertor holder is still separate as it would cost a bomb to fashion it out with a block the diameter of the discs. It can either be like my old design, with a lip at the bottom so that the convertor can be inserted from the top end and adhered to the bottom _or_ it can be the exact dimensions and convertor placed in snugly in the shaft.


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## gadget_lover (Jan 23, 2006)

I'm pretty sure that pbarrette was trying to explain that any heat sink in an enclosed container will quickly heat up to the point where it will not absorb any more heat. The more mass you have, the longer till it reaches that point. Even so, it may be only minutes. The fins provide increased surface area for air convection IF it's not in an insulating container like a plastic flashlight.

Every joint between two pieces of heat sink make sthe heat transfer a little less efficient. In the picture above you have 4 junctions; LED to button 1, button1 to disc 1, disk 1 to button 2, button 2 to disc 2. The outer edge of disc 2 will always be cooler than button 1, even when it's reached its steady state temperature.

Your best solution is to use a solid disk the size of disc 1, button 2 and disc3. Drill a series of 8 to 10 1/4 inch holes around the flashlight's bezel. After every thing is in place, put a 1/4 inch thick aluminum ring around the outside of the bezel and run screws though that ring, through the bezel and into the heat sink. That would give you an interface between the air and the heatsink so the heat can dissipate.

In general, if run the LED at less than 100ma you will not need to get rid of that heat. That's per the Lumileds spec sheet.

Daniel


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## Chop (Jan 23, 2006)

Yeah, gadget lover hit the nail on the head. Fins on the outside of a light, to increase surface area is a good thing, but on the inside, it actually makes things worse. A solid heat sink would be better, but even still, you're still going to have problems unless this is going to be a short run light due to its being made of plastic. I would, at least, consider having an aluminum head made while you're at it. This would give you a thermal path to get the heat out of the light. The head doesn't look complicated. Just a big bezel ring.


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## scott.cr (Jan 24, 2006)

I concur 100% with gadget_lover. You'll want the heat mass so put as much material into your 'sink as possible.

If this were one solid "hockey puck" it would be very easy to machine a little depression for the converter board. Then you could hold it in with screws or a C-clip. Personally I like the C-clip solution and you can back up the converter board with a spring (or springs) to keep things from rattling around... and nothing to work loose, like screws.

*Of course it could be said that all flashlight nuts have a screw loose.

By this time you're almost 100% re-engineernig the flashlight... for this much machining effort it'd be worth considering making a whole new body and reusing the bezel, lens and reflector.


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## LEDcandle (Jan 24, 2006)

Hi gadget lover, the alu ring idea sounds good. I did think of something like that for my other plastic flashlight but screwing it to make the contact is a great idea. 

I understand the whole concern over all that heat trapped inside an insulating plastic. I was thinking if the block of aluminium was too thick, the heat might not 'move' fast enough away from the lux, so that's why I drew a dual disc kinda thing. But yeah, I guess that holds much less than a solid block and transfers slower than if the entire thing was one piece instead of separate pieces.

Chop, an alu head also sounds good. But all this is driving up the cost for a 'hobby mod'. haha...  As I was saying, I did run a lux III in another plastic light (direct drive by a single li-on). When the li-on was fresh from charger, the current was like 750 ma, and the light got hot pretty fast.

I stuck a probe onto the lux star and within 5 minutes it was past 70deg celsius. Some days later, I stuffed a bunch of 8 coins behind the star and the light could run 10 mins and was still under 70 deg. By 10 mins, the voltage of the li-on had stabilised at around 3.7v and current was about 300 ma and heat seemed to be quite manageable from then on. 

So I'm thinking if I run a low current Downboy, maybe a 500 or less, the light be able to run 20-30 mins at a go wif a good chunk of alu inside? That's what I'm betting on. I guess I'll have to try it to know!


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## LEDcandle (Jan 24, 2006)

scott.cr said:


> I concur 100% with gadget_lover. You'll want the heat mass so put as much material into your 'sink as possible.
> 
> If this were one solid "hockey puck" it would be very easy to machine a little depression for the converter board. Then you could hold it in with screws or a C-clip. Personally I like the C-clip solution and you can back up the converter board with a spring (or springs) to keep things from rattling around... and nothing to work loose, like screws.
> 
> ...



A big hockey puck seems to be the best solution. The depression in the bottom of the hockey puck should work for the convertor.

But I'd still need the button to raise the Lux a little higher so it peeks into the reflector 

Thanks for all the great suggestions guys.. pardon my poor design considerations. I'm still very new at this. If it ends up being a simple hockey puck, that'll be great too for the cost. 

Scott, let me know if there are anymore issues or can I start giving you dimensions?


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## rgbphil (Jan 24, 2006)

I have an idea that may help with designing heatsinks......though there may be some issues that need looking into.

Some background first, I've also got an interest in Japanese swords and knife making. One part of the sword is a copper/brass object called the Habaki. This is the plug if you like, that seals the blade into the wooden sheaf (saya) and both protects it from the outside world of corrosion and also holds the blade into the proper position so that the delicate edge doesn't touch anything.

I remember reading long ago a sword maker creating very beautiful habaki from alternating layers of copper and brass that have been silver soldered together. I'll need to do a deep search of my material to find a link, but basically the craftsman cut many layers of sheet copper (and brass) into roughly the shape he wanted then compressed them together after coating with the solder using a vice. The whole construction was heated again under compression till it formed one solid block which was later filed to the shape of the blade.

Of course you'd omit the brass, but I would imagine that you could create heatsinks of almost any shade with readily available sheet copper rather than complex machining of block copper. You could even create a whole LED head, fins and all using this technique.

The issue would be whether the silver solder layers would still provide enough of thermal path to be useful. I would think it would....but I can't say for sure.

Hope this helps, or at least gives you some ideas on construction.

Phil


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## rgbphil (Jan 24, 2006)

re previous email I've found my link on constructing solid copper structures using sheet metal.
http://home.mchsi.com/~samonji/habakitutorial1.html
I can imagine disks of copper cut to size, with notches on the outside for 'fins' and internal holes for wire looms/circuitry etc.
Phil


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## LEDcandle (Jan 24, 2006)

rgbphil said:


> re previous email I've found my link on constructing solid copper structures using sheet metal.
> http://home.mchsi.com/~samonji/habakitutorial1.html
> I can imagine disks of copper cut to size, with notches on the outside for 'fins' and internal holes for wire looms/circuitry etc.
> Phil



Very nice rgbphil! I'm sure others will find this info useful. As for me, I can only awe at it as a layman 

These are the dimensions and the final design :-






Pls point out any possible errors or miscalculations. The measurements aren't pinpoint accurate but I think they'll do. 

I tried the luxeon, it doesn't focus when sitting right at the base. It needs to be quite a bit into the reflector. I have specified a height (1.7cm) which should be slightly longer than necessary, and I will start filing it till its the right height. 

The heatsink "hockey puck" will just be as you guys suggested (aluminium or copper?). It should be 0.8cm thick disc with a 5.4cm diameter. The hollowed out bottom side will fit the convertor. I will prob need to solder on a small spring to the bottom of the convertor to make contact with the (+) contact point of the batt-pack. 

_*edit :_ I think the empty space under the reflector can be utilized. Let me draw a re-designed heatsink in the next post.

I can probably handle the drilling myself. 

Scott, pls quote me a ballpark figure through PM and also, I might need other bits and pieces for adjustments and future lights etc. You can also email me at kryndal2 @ yahoo . co . uk (close up spaces). Thanks!


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## LEDcandle (Jan 24, 2006)

New proposed heatsink :-


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## greenLED (Jan 24, 2006)

I dont' undertand why the Lux' pedestal is a separate piece.


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## LEDcandle (Jan 24, 2006)

Because it'll waste a lot of material (and cost a lot) machining down a 5.4 cm block into a 1cm neck/pedestal? That's the impression I'm getting how it works.

A smaller diameter stock would probably be better to make the neck?


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## scott.cr (Jan 25, 2006)

That last design could be a winner. I have some FORTAL in the correct dimension. Since the LED mount is only 17mm "proud" of the heatsink, it may be feasible to have a one-piece unit.

The 1.41-cm hole is for the converter board? Do you have something in mind to keep the converter in place?


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## LEDcandle (Jan 25, 2006)

scott.cr said:


> That last design could be a winner. I have some FORTAL in the correct dimension. Since the LED mount is only 17mm "proud" of the heatsink, it may be feasible to have a one-piece unit.
> 
> The 1.41-cm hole is for the converter board? Do you have something in mind to keep the converter in place?



Fortal? Is that like expensive aircraft aluminium? Heh... Anything cheap and good will be great for me for this mod.

Ok, one piece sounds better, so if I need to adjust the height of the neck, I guess I'll have to file the top. 

Yup, the hole is supposed to be for the convertor. Haven't really planned EXACTLY what to do, but prob will line the shaft walls with some adhesive and stick the convertor in. Or maybe line the shaft with some insulating tape (which is a little 'rubbery'), and it'll hold the convertor snugly. 

The 0.6cm isn't much space for the convertor to move around back and forth so that should be fine. 

Additional stuff I might need are just some buttons and maybe some small discs for future mods. You can email me or PM est. pricing and I will confirm with you the exact pieces and dimensions. Thanks!


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## gadget_lover (Jan 25, 2006)

ledcandle said:


> Or maybe line the shaft with some insulating tape



The converter also creates heat, and (depending on the converter and the power levels) it may overheat if you used insulating tape. They make a nice epoxy that conducts heat fairly well AND is non conductive. Artic Alumina (I think).

Daniel


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## LEDcandle (Jan 25, 2006)

Thanks for the tip Daniel. Yup, we were discussing Arctic Alumina in another thread  I couldn't find it locally yet because all the PC shops only carry non-adhesive arctic products.

I have my industrial thermal silicone though, which is an insulating thermal paste too, but it just takes too damn long to cure


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## scott.cr (Jan 26, 2006)

If you can find it, go for Loctite "Output" #315. I briefly mentioned this in another thread. 315 is a non-electrically conductive epoxy for heatsink applications. It contains glass microbeads to guarantee a non-contact assembly, so you don't have to worry about pressing your components a little too tightly together and having some voltage leak.

It's sold locally to me; online it's a bit hard to find. Contacteast.com sells it, but they want like a $30 hazmat charge. (The Loctite 315 kit costs like $18.)


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## scott.cr (Jan 26, 2006)

I forgot to mention that I have a FORTAL scrap that's just about the right size for your heatsink. The best part is that it's free, because I won't likely be able to use it for anything else.


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## LEDcandle (Jan 26, 2006)

scott.cr said:


> I forgot to mention that I have a FORTAL scrap that's just about the right size for your heatsink. The best part is that it's free, because I won't likely be able to use it for anything else.



Haha, sounds good  

I'll think about the 'extras' I need, and if this requires you to use a new piece of stock, just charge me for it. And your workmanship fees for everything of course 

I'll post up the requirements here or do you have an email I can contact you at? After giving you the specs for the extras, when do you think you'll roughly be done with this whole 'project'? 

Thanks Scott!

P/S I saw your loctite post in the other thread. Thanks for the tip.. will try to look for it!

add: Hmm, loctite #315's thermal conductivity is only 0.8 w/mk. My silicone is 1.7 and artic silver alumina adhesive (not normal artic alumina adhesive) is something like 8ish? The glass bead isolation thing does sound good though


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## LEDcandle (Jan 29, 2006)

Think the extras I need will be :-

1) 8mm diameter round stock x 1 "rod" (If it doesn't come in that size, then you prob have to machine it for me)
2) 10mm diameter round stock x 1 "rod"

Length wise around 10-15 cm or whatever its original length is if it's shorter than this. The basic idea is to have a couple of rods so that I can cut 'em up for use for anymore 'pedestals' I might need.

I think everything should fit in a Global Priority Mail small? Let me know the details Scott! Thanks! 

The basic


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## scott.cr (Jan 30, 2006)

Sorry, I haven't been on the forums for a few days.

I can turn down some aluminum round bar to just about any length under 8 inches/20 cm or so. So I can send you some longer lengths and you can probably find someone locally that can face them down to length for you.

EDIT: If you're 100% sure the dimensions are correct I'll get started.


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## LEDcandle (Jan 30, 2006)

Hi scott! Welcome back 

20cm seems to be able to fit a GPM small envelope, so let's go with that length. I think I'm good to go, so to summarize, this is what I need :-

1) Heatsink for flashlight mod, one piece design with 17mm pedestal/neck (dimensions according to the last drawing, except button from previous drawing is integrated)
2) 1 x 10mm dia, 20cm length round stock rod
3) 1 x 8mm dia, 20cm length round stock rod 

You can contact me at kryndal2 @ yahoo . co . uk (close up spaces) for payment and other issues. Will pay by paypal cash. Cheerios!


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