# Need a component machined for a special project



## Lumbee1 (Nov 14, 2006)

I need a small block of aluminum machined for a special project I am building. The block needs to be 26mm x 26mm x 15mm (L x W x H). I need a 20mm radius cut in the top and a 18mm radius cut in the bottom. I have attached some simple drawings that I made in Photoshop for a better understanding.


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## PhotonFanatic (Nov 14, 2006)

Bikelight?


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## highorder (Nov 15, 2006)

I dont have any metric cutters handy. how tight are your tolerances?
18mm= .709"
20mm= .788"

+/- .010" (.25mm) makes this an easier job.


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## scott.cr (Nov 15, 2006)

highorder said:


> I dont have any metric cutters handy.



How would you cut this shape?

Offhand I was thinking of a boring head, but I've never done a job like that.


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## highorder (Nov 15, 2006)

the easiest way would be to use a horizontal mill with a proper radius cutter, taking depth pecks until the desired radius meets the vertical sides.

there is no one right way to do anything in the shop though:thinking:


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## will (Nov 15, 2006)

Another way is to use a boring bar in a vertical milling machine, put the work in the edge of the vice. For a small piece - lots of individual steps to make the piece. a suggestion - make 2 ...


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## highorder (Nov 15, 2006)

case in point, that is also a great idea! with constant feed in the Z axis, there are no steps...


let me go sharpen and calibrate my boring bar...


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## Lumbee1 (Nov 15, 2006)

PhotonFanatic said:


> Bikelight?



Yes, it will be a Mag D Cell body cutdown with a remote battery pack mounted on a 31.8mm handlebar. The Al block will be JB Welded to the bottom of the Mag. A anti-slip cushion will be placed between the bottom of the block and the handlebar. The handlebar ~32mm = 16mm radius with a 2mm buffer for the compressed cushion means an 18mm radius for the bottom of the block. I plan on using rubber rings similar to the DiNotte to hold the light to the handlebar.

With this design, the Mag can be removed from the bike easily and carried around without having a chunky handlebar mount hanging from the bottom of the light. The block should also be tall enough to act as a anti-roll foot for the light. My previous attachment design for the light used a reflector mount. After several fittings, I think it would have been quite flimsy with aggressive trail riding.

I am a DIY kind of guy but I want this block fairly accurate. I typically work with wood so I would have had to "machine" this out with a belt sander :laughing:. I am a DIY'er because I am always looking for the cheaper custom solution to make a much better product.

For the others that responded:
Top ra[size=+1]dius should be as accurate as possible 
1 9/16 diameter = 0.78125 radius 
allowing tolerance for JB Weld
0.79 in radius should be perfect (20.06mm)

The bottom radius doesn't have to be as accurate.
I can always add an additional layer of anti-slip material.
If the radius on the bottom matched the top, that would work as well.

By the way, what kind of costs am I looking at?
If this is successful, I might require additional pieces to be made to modify additional Mags for sale. Tri-CREE Mag for biking should be a cheaper and brighter solution that what is currently available :naughty:.
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## will (Nov 15, 2006)

Are you gong to use JB cold weld epoxy? IF so - I would be concerned about it holding together.


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## highorder (Nov 15, 2006)

with proper surface prep, those two items will never be seperated again.


I am looking for tooling... I will let you know if I can help.


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## Lumbee1 (Nov 15, 2006)

highorder said:


> with proper surface prep, those two items will never be seperated again.
> 
> 
> I am looking for tooling... I will let you know if I can help.



I agree. Proper surface prep is key here.

Thanks highorder.


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## will (Nov 15, 2006)

I have had success with JB and failures, The failures have most often occured where there is a lot of torque being applied to the two components. I did do the surface prep and all that.


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## aosty (Nov 15, 2006)

I'm sure you have seen them before but just in case you have not, TwoFish offers a product that's pretty much exactly what you described... particularly the "Lockblocks Flashlight Holder". It's made of rubber with velcro straps.

http://www.twofish.biz/bike.html 


I'm all for over-engineering :naughty: but they will be lighter, shock absorbing, more affordable, less hassle, and available today.


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## Lumbee1 (Nov 15, 2006)

aosty said:


> I'm sure you have seen them before but just in case you have not, TwoFish offers a product that's pretty much exactly what you described... particularly the "Lockblocks Flashlight Holder". It's made of rubber with velcro straps.
> 
> http://www.twofish.biz/bike.html
> 
> ...



Lockblock only supports AA light. I plan on using a Mag D cell which is significantly larger in diameter. The lockblock holder also doesn't specify which handlebar diameter is supported (25.4mm or 31.8mm).

I have already made a device to mount my Fenix L2T to my handlebar. The L2T is just not bright enough.


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## aosty (Nov 15, 2006)

Lumbee1 said:


> Lockblock only supports AA light. I plan on using a Mag D cell which is significantly larger in diameter.



Look at the "Cyclopblock"... I'd bet the mentioned "C" size is probably due to weight... should be fine with your shortened D. If the straps are not long enough, they are not permanently attached and can be easily replaced.

The "MegaBlock" might also work... even though the straps are "parallel", they can be removed/realigned to be "perpendicular" to each other. I use a LockBlock for a helmet light and changed from "perpendicular" to "parallel" to fit the helmet vent.

As for fitting your handlebar, the rubber is pliable to accomodate different tube sizes.


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## Lumbee1 (Nov 21, 2006)

Bump


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## MoonRise (Nov 22, 2006)

Suggestion on making a mount. Take a larger block of aluminum, drill/bore the desired perpendicular holes through the block in the desired location and orientation as regular holes, and then 'waste' the extra material.

Not the way to go for a production unit because of material and machining costs, but simple and quick for a one-shot.

Second suggestion. Do first sugestion except do not 'waste' the extra material. Instead, then 'slit' the block and make the block like a set of scope-mount rings. Drill and tap and countersink/counterbore for desired mounting hardware and avoid the whole epoxy idea. Use thumbscrews or wing-nuts to make it tool-less. That mount wouldn't slip in an endo!


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