Small fillet radii

[borjame]

I'm looking to get some parts machined and ideally I would like some small fillets, under 1/32 but I'm worried about cost. The shops I deal with in Aerospace all kick up the cost for really small radii, is there an industry that uses small radii as course of business like watch makers or lock makers? Any companies that come to mind that can handle small radii cheaply?

 

small fillet radii need not be expensive if the part allows for using larger diameter end mills with a corner radii ground in. I would try some different shops, as it may be that they have grown too comfortable with your business. Familiarity has a way of increasing job costs over time, especially if they think that you are not shopping around. I know this is true because I was a shop owner for many years, and I always knew who was good for a little "padding" on the estimate. Sad but true !!!

 

[TVP]

I have to agree with ornery norsk-- end mills with corner radii are a good compromise on something like this. But overall, I don't see why this type of radius should be so expensive. Injection molds for plastic components often have small radii (less than 1 mm or 3/64&quot, and this doesn't necessarily make the final mold cost excessive.

 

[meintsi]

A #2 lathe insert includes a .030" radius as it cuts.

Moving to a #1 insert (.015" radius) is not hard in the CNC environment today with quick change tool holders. Note #0 inserts have a .008" radius.

If you getting a large cost increase because of this DEFINITLY find yourself a new machine shop.

Mill radii do take more time but should drive the cost up that significantly. If you don't use your head, your going to have to use your feet.

 

[gbent]

You don't mention where you want the small radii. Is it a mill or lathe part? If it is a mill part, how deep do you want the radii? If you are asking for a 1/32 radius that must be cut with the side of a endmill to be 1/2 inch deep, that will be quite pricy. If the radius can be put on with a bullnose endmill, that shouldn't cost at all. Also, what is your tolerance on the radius? I have seen a clearance radius called out as .0325, and a general drawing note of .xxxx dimensions +/- .0005. The draftsman didn't have a clue there was a problem, and the checker didn't catch it.