1mm Ball Nose Bit Advice

[dcrowder]

I'm taking delivery tomorrow of a 1mm Ball nose bit for carving some details in wood but I'm under no illusion this isn't going to be easy and I'm going to have to be careful with my feeds.

Does anyone with experience have any advice that they could share? Speeds, stepovers, stepdowns - anything really. I just don't want to break a bit that isn't cheap on it's first run! The relief is approx 12-15mm from top to bottom. When I say wood I'm flexible with soft/hardwood and am prepared to suit the material to the application. If my wishes aren't possible then I'd even be prepared to work with something like foam board.

The carvings are going to be approx 300x400 but I need the 1mm bit to achieve the resolution I'm after.

Cheers!

edit: this is the bit.... http://www.shop-apt.co.uk/2-flute-long-neck-carbide-ball-nose-end-mills-55hrc/long-neck-ball-nose-carbide-cutter-1mm-dia-12mm-neck-length-50mm-long-55hrc.html

[lucan07]

I grabbed a cheap set of PCB micro endmills on eBay to start with 10 for £6, I know they're limited quality but I would rather use these to get an idea of feeds and speeds my machine is capable of before attempting any work with the better quality bits.

[phill05]

You don't need a ball nose to produce this type of project I work in stone, metal and woods cutting relief carvings and use V cutters or engraving cutters between 90 degree and 10 degree with a 0.020 truncation ( slight relief off point).
I would run a roughing pass with either a 4 or 6 mm ball nose leaving 1mm of material to finish pass with the engraving cutter and you will be fine you should have no broken cutters.
Don't forget if you have any deep, steep sides in the relief you need to use a smaller angle cutter for the finish pass this is why I go down to 10 degree inclusive angle, if you intend to cut a lot set yourself up with a cutter grinder you can regrind to suite your project then.

Phill

[dcrowder]

Thanks, for the advice chaps! Phil, could you give me link to some of the bits that you are talking of? I think I have seen what you are talking about used on Youtube but thought that they'd not get down steep (almost vertical) sides and into tight spots between objects in the carving.

[phill05]

I use http://www.pantograph.co.uk/engraving-cutters-diamonds.htm brown ring and orange ring carbide, they also do HSS as well

they will grind to any angle you want, and they offer a regrind service as well.

Phill

[dcrowder]

I'm only seeing cutters down to 3mm there... do they grind them down to a smaller diameter too? I really need to be carving at 1mm.

The 1mm ball nose bit I got was doing a lovely job - I started slow and gradually stepped up the feed, but when I got too brave and ran it at 40mm per sec it snapped after a few minutes :(

I'm really keen to try something else though and am a bit more confident that I won't break it next time.

[dcrowder]

I use http://www.pantograph.co.uk/engraving-cutters-diamonds.htm brown ring and orange ring carbide, they also do HSS as well

they will grind to any angle you want, and they offer a regrind service as well.

Phill

Thanks again for the tip Phill, I'd have never found it otherwise. The chap I spoke to there was really helpful - the cutters are a really good price compared to the ball end mill I used and the regrind service really improves their value further. Going only by service as I've only just ordered the cutters this afternoon - but I'd highly recommend this company to anyone.

[phill05]

but I'd highly recommend this company to anyone.

You won't go wrong with them I am a well satisfied customer for many years, for std items it is next day delivery even if you order late afternoon, have fun.

Phill