Dovetail cutter / radius cutter for aluminum

[Reddinr]

So I have a small project. I need to mill into an existing assembly an arca-swiss dovetail. Arca-swiss is a sort-of standard for mounting photography equipment to tripods, etc. The dovetail is 45 degrees and the thing I'm machining is some sort of anodized aluminum. I don't want to buy an attachable plate because I need to minimize the overall height and it happens that the rail is just slightly wider than needed, perfect.

So, I'm looking for a decent 45 Deg. dovetail cutter and a 1/16" radius cutter that will work well with aluminum. I have an RF-45 style mill, 3600 RPM maximum. What is a decent quality brand of cutter and source that won't break the bank?

Also, what is a tough, black finish I can put back on the machined surfaces? (Not anodize.)

Thanks!

Here is (roughly) the profile I'm going for.



What I'm making:
I am making a stepper-controlled focusing rail for macro photography. I found some low cost, used THK rail assemblies and I'm using one of them for this.

The rail:

 

[Ischgl99]

If you are just going to use it for this, woodworking router bits work fine on aluminum and are cheap. I am a photographer and made a few lens plates, for the bottom radius, I just used a file to round it over, it is not critical at all. Take a look at your clamp to see how much of a radius is on the inside corner to see how much you need to do on the plate, my clamps have a fairly sharp corner, so just knocking off the edge would be enough. For my 45 degree cutter, I believe I bought one of the house brand cutters at Travers, it says made in China, but it works just fine on aluminum.

I can’t help on the durable finish, I just spray painted mine since I didn’t have the capability to do anything else, and that did not hold up for very long.

I would be interested in seeing your macro rail when you get it done. I haven’t done much macro, but I am doing more product photography and a motorized rail might be nice for that.

 

[Reddinr]

Didn't think about router bits. I might even have one.
I'll post a pic. of my completed rig once I get done with it. I actually started this quite a while ago but shelved it due to other projects getting in the way.

My goal is to do "focus stacking" to get a large depth of field. The motorized rig should make that easy and fast.

 

[pontiac428]

Can you grind a profiling D-bit that combines the dovetail and the radius? It's a little dovetail, in aluminum, so not much load... make it a single step process.

 

[Reddinr]

Hmm. No router bit on hand. It looks like the radius that is on the part will be fine for one edge and I'll probably file the other radius.

 

[Ischgl99]

Most of my projects have been shelved at various stages, I'm not sure what the count is currently lol

Focus stacking is exactly what I was thinking about for product photographer, I look forward to seeing what you do with this.

 

[woodchucker]

You can cut a bit for a smaller fly cutter to cut the exact shape you need.
As far as paint, consider using Rustoleum etching primer , followed by the rustoleum paint of your choice,
Fly cutters can be used with small cuts to profile ..

 

[Ischgl99]

You can cut a bit for a smaller fly cutter to cut the exact shape you need.
As far as paint, consider using Rustoleum etching primer , followed by the rustoleum paint of your choice,
Fly cutters can be used with small cuts to profile ..

The etching primer is a good idea, I'll have to try that on my next rail. I did not use a primer since I didn't have any on hand, but that might help.

 

[ChazzC]

You can cut a bit for a smaller fly cutter to cut the exact shape you need.
As far as paint, consider using Rustoleum etching primer , followed by the rustoleum paint of your choice,
Fly cutters can be used with small cuts to profile ..

Rust-Oleum makes several etching primers, and also recommends their Universal Bonding Primer for Aluminum: best to check with Rust-Oleum for a specific recommendation.

After some research, I recently used their Universal Matte Farmhouse Black spray paint combined primer/paint) on an exterior Aluminum post light column and it came out looking like it had been powder coated, with a smooth, hard, matte finish that has held up to daily rubbing from the garden hose without any wear. I used 220 wet/dry AO paper and a green Scotch-Brite pad (both wet) to remove loose paint & feather, rinsed with water and a final wipe with 91% Isopropyl Alcohol. Then 3 costs of paint. All of this outside in the Sun with a light breeze (after thoughtfully moving my wife’s car).

You make be able to find a local outfit that can anodize the finished part as part of a larger run at a reasonable price. The disadvantage of paint on a sliding part is that it will wear off; anodizing creates a hard surface layer that is reasonably wear resistant.