Edke6bnl - about rounding over aluminum edges

[C9]

Enjenjo posted an excellent tech article on making column drops and the like a while back.

Ed - pretty sure it was - posted a pic of one with nicely rounded edges.

I understand this was done with a wood router.

I'm fairly sure a carbide router bit with ball-bearing guide was used.

Did you cut the rounded edge in one pass or were several done?
Variable speed router?
Mine's a fixed speed - 30,000 rpm fwiw.

I have several American made carbide router bits with ball bearings, but don't have the one in the radius I want.

I do have some cheap-o Chinese carbide ball-bearing bits - new in the box at a garage sale, couldn't resist - that are the right size and will probably work ok in wood.
I am wondering if the bit you used to round your aluminum column drop was made in the US?
I don't mind getting one if necessary and have to go to Home Despair today anyway.

I know I could give it a shot with the Chinese bits and see what happens, but thought I'd ask first.


Like many, I haven't got a lot of faith in Chinese tools, but will note that the Chinese made carbide lathe bits work well and last a long time turning metal in my lathe.
I'll also note that these bits are about ten years old and quality may have gone downhill.


Reason I ask, I've got my oil/air separator done in prototype form and it's installed.
I haven't done a full throttle run to see if it is going to work, but a couple of 1/2 - 3/4 throttle runs look promising.

I'm kinda bad about making 'stuff' in finished form; buffing etc., but this time around decided to save some time and make the device up to the prototype brushed aluminum finish stage with 90 degree edges in case it didn't work out and becomes another pretty thing hanging on the "Wall of Shame" where the not-used or failed projects go.

Nice part about the gadget is, disassembly is easy and bringing it to a more acceptable level of finish should be easy as well.

After I run the car a little more and decide if the sparator does what it's supposd to I'll post some pics and text.

[Fat Cat]

We use non-ball bearing carbide bits. They are craftsman brand that came with the router 20 years ago. It is done in multiple passes if it is a radius larger than 1/4"

[Ed ke6bnl]

I did the routing in multiple passes with a carbide bit and a bearing follower.  There is a recommended direction  cc versus ccw, but I don't recall which, and what I would do is take a scrap piece of aluminum and make a sample test prior to going to the finished part.  Ed ke6bnl
It is not much differant then the regular wood routing.

[C9]

Thanks guys.

Direction of cut makes a difference.
When using a mill it's called "climb" milling.
Cutting with the direction of rotation, but you need a very sturdy, well clamped setup.
Otherwise the mill cutter gets 'sucked' into the metal and things go to heck in a real hurry.

Cutting against the direction of rotation is a lot safer.

Same deal when cutting wood in a router, go the wrong way when cutting freehand and the bit gets sucked right into the wood.
Many bad words follow....

I appreciate the advice.
I have a roundover mill cutter, but it would be a lot more trouble to use than a router since I'd have to set up the rotary table for the curved part of the cut then go to a straight cut at the right place.
Plus, I need to make a centering device for the rotary table before I could do that.

As soon as I get a Honey-Do project out of the way I'll get the mount rounded and let you know how it went.

[Ed ke6bnl]

I know what you mean I have never used a round over bit in the mill and it would have been a lot harder to set up even though I made the outside radius on a rotory table, and the center hole with a boring bar..  good luck I have seen some of the nice work you do. Ed ke6bnl