Cup burr conundrum.

[Solunar Silver Studio]

I've just got my order...brilliant delivery service as always!! But packed with my package of goodies was a touch of disappointment too...

I ordered a cup burr to make the job of rounding off my argentium earwires less of a chore. I use 0.7 and 0.8 wire so I thought if I ordered a 1mm cup burr it would do the job with a bit of wiggle room. When I saw it in the package I knew something was a bit amiss as it was so small


I appreciate that you measure the size of all other burrs by the outside diameter as that is the 'business' end...but surely a cup burr needs to be measured by the inside dimentions otherwise it would be total guesswork as to what size wire would fit inside it.

What size would I need to get in order for it to work on a 0.7 and 0.8mm wire?

So that is totally useless as I'm not even sure if a 0.5mm wire is working in it...it is so darned small I can't see what is going on with my specs and a magnifier with a 1.8x and a 1.2x lens in it!!

I also managed to miss something off my order - which I am right miffed about...and since it is only worth £10.98 the freepost won't apply...mutter, mutter!!

Anyway - I would appreciate your advice about what cup burr I should have got if a 1mm will not work on a 0.7 wire....

[Di Sandland]

I can only sympathise cos I did exactly the same thing with my cup burr - ordered a 1mm. But this from George - after I'd bought mine



For wire ends, you might want to get a cup burr (you don't need a flexshaft, you can just pop it in a pin vice) Burr:busch 411 Cup 1.2mm - Cooksongold.com

As a very simple rule of thumb, you need two gauge sizes higher than the wire you're rounding, so the one above is perfect for 0.8mm wire. It only takes a couple of twists (always in the same direction) and the wires are perfectly rounded. It really is much quicker than using a file, especially if you're doing a few at a time.

[Emerald]

get Geti to go and get you one he is in the quarter make himself useful, time to get your coat Geti and a 30 p stamp he he

[Solunar Silver Studio]

I can only sympathise cos I did exactly the same thing with my cup burr - ordered a 1mm. But this from George - after I'd bought mine



For wire ends, you might want to get a cup burr (you don't need a flexshaft, you can just pop it in a pin vice) Burr:busch 411 Cup 1.2mm - Cooksongold.com

As a very simple rule of thumb, you need two gauge sizes higher than the wire you're rounding, so the one above is perfect for 0.8mm wire. It only takes a couple of twists (always in the same direction) and the wires are perfectly rounded. It really is much quicker than using a file, especially if you're doing a few at a time.

Typical!! It's one of those things that could do with a bit more information in the catalogue don't you think! How is a buyer supposed to know that...??
Have you tried the 1.2 then Di? I can't go wrong with this one if I order it?? I had all my earwires out this morning...cos I knew I could rely on Cookson's excellent delivery...and I was going to have an earring day! Bah!!

I'll get this ordered and then try again tomorrow!!

[Di Sandland]

yeah - the 1.2 worked fine for me. And, yes, that is a case where more info on the site would help...

[mizgeorge]

I use a 1.2 for .8mm wire Barbara if that's any help? Make sure you always have it rotating in the same direction or you'll shorten the life of the burr dramatically.

Cup burrs are always measured using an outer diameter as they differ quite a lot in how the insides are configured depending on manufacturer and style.

[Solunar Silver Studio]

So how on earth do you work out which one you need then?? Purely trial and error?? The one I bought was the Busch Cleancut rather than the Busch 411....does that mean I might still have problems if I order the cleancut 1.2 instead of the 411 1.2???

Excuse me while I scream!!!!

[geti-titanium]

Don't forget digital verniers are pretty inaccurate too unless you spend hundreds on them.

Sorry Jason - you're miles off there. A £25-£35 digital caliper gauge these days is really accurate - the inaccuracy is usually down to the person using it as a rule.

I've been using digitals for a good 15-20 years now and the first ones were hideously expensive. The quality of todays generation calipers is in excess of the first ones.

[mizgeorge]

Either 1.2 will be fine B - the only difference between the regular and the cleancut is in how the metal is removed - the regular one creates dust, the cleancut a little swarf (which is slightly more convenient to put in your scrap pot, and also much more convenient for embedding under a fingernail (don't ask how I know this.....).

As for knowing which one, it's a mixture of trial and error and research

[Petal]

After reading all these posts I think I'll remove the cup burr from my basket and think about possibly getting some files instead - they sound like a lot less hassle .....