Diamond Bit Christmas Gifts

[Jidis]

Hey guys-

I went ahead and bid on this giant bag of some diamond dental burrs, figuring some of you could get a good deal on the surplus.

http://tinyurl.com/cncw6

I saw them recommended for PCB work a long time ago and had been using a Dremel brand version for a long time, until I drilled something too hard and dulled it or something. I bought a second one a couple weeks back and busted the ball off after five minutes with some careless side-to-side pressure. :'(

The Dremels were a tad too big anyway (2.5x the size of these) and were running me 5 or 6 dollars a bit.

I'll probably keep 25 of these, as I don't know if they last as long as what I've used. If they do, I'll have way too many. :D

You can get them for an exact percentage of what I paid ($26 USD). I don't have any idea how "parts sale" offers usually go in the MIDIBox world, and I don't want to risk leaving anybody out that needs them, so I'm guessing selling them in quantities of ten or twenty would be fair (suggestions??). That will only run $2.60/10 or $5.20/20. I suspect this guy is sending them in a regular postal envelope, as he didn't charge shipping. I've gotten a lot of help in here, so if I can mail them out with stamps like that, I'll gladly pay the US postage, and maybe the overseas if it's not drastically higher. PayPal would probably be the simplest for the bit cost.

                                                                                          -Happy Holidays!

George

PS- Be warned --> These are suspiciously inexpensive. They are said to be top quality, just bulk with no brand name, and he's got 643 feedback hits, all positive. I hope that's an accurate description, but they might be carved out of toothpicks. ;)   

[Jidis]

I hope that's an accurate description, but they might be carved out of toothpicks.

Well, maybe not quite toothpicks...... ???

They actually already got here yesterday. The verdict is still out on the quality, but at 26 cents for something that usually costs me 6 dollars, I probably shouldn't have gotten my hopes up. ;D

They don't appear to be as sharp as the Dremels I'm accustomed to, but I can't really get a good look at the ball end without a microscope or something. They also weren't very well sorted. There appears to be a bunch of different ones mixed in with this first bag I've opened, with the average checking in at closer to 1mm. Throwing three other random ones in the chuck to double check the cut quality and drilling way too fast, I've now snapped the balls off two! (I guess that's why you have to buy 100)

Doesn't look like anybody needed any here, but just in case, I thought I'd mention that I may be deciding that they suck. I'll probably email and tell them what's happening, as they do have a heck of a lot of positives and a money back guarantee, so they may end up headed back if things don't shape up.

I could be back where I was in the mini-bit market if anyone knows some good deals. The Dremel burrs, although a bit too large, were serving me quite well, and were a big improvement over the quick dulling and breaking of the regular steels.

A quantity of really small (1mm) regular drill bits might also suffice. I used to be able to get a glass tube of about 5 such bits by Dremel (even had a PCB in the pictures), but they've stopped selling it here. 

-George     

[smashtv]

Kicking the wayback machine with the search, I found this: http://www.midibox.org/forum/index.php?topic=748.msg4267#msg4267

;)

They are cheap when you compare the hole yield per bit with any of the standard carbide pcb bits or HSS bits that like to break.

Best!

Smash

[Jidis]

Smash,

Thanks! Wasn't even aware router bits got that small (must be machinist stuff). I already hooked up with a whole box of .033" (#66?) carbides from a place that someone in the PCB Yahoo group turned me on to. He's at http://toolsandtunes.com/ and also is known to have weekly eBay auctions which end early on Monday mornings. If anyone in the US needs some, he's nice as crap and I had them in a couple days. They're the really solid industrial ones with the beefed up shanks, label rings and a hard plastic storage box. They were only 12 bucks or something. I think they're resharpened industrial surplus or something. 

I had a thread on the Yahoo group and was told not to use the burrs by all but one person. The burr idea was something I read in a usenet discussion, and it wasn't regarded as a bad idea by some people who seemed to know what they were talking about, plus as I mentioned, the one I had been using the past couple years cut quite well. All I can figure is that there are differences in the diamond textures or cutter shapes. I do run at a really low speed in my press, so maybe they do well at the higher speeds everyone recommends for PCB work. I emailed the seller twice over a couple weeks, to see if he wanted me to send any back (he has a guarantee),  but I've gotten absolutely no response. I'll wait in case he's gone for the holiday or something, but I'd feel foolish if I left him a positive, and with around a hundred eBay purchases, I've never had to leave anyone anything neutral or negative.

BTW- I'm planning to build a small press exclusively for a roto tool, and will probably get another one just for that. I also had a thread in the PCB group about what the more quiet rotos were. On high speed, mine sounds like a swarm of bees (not too fun for 2 or 3 hundred holes). The only specific recommendation was a really old, discontinued Black & Decker, and the guy said that there may be better ones now. If anyone's owned or heard a few different ones, I'd be interested.

                                                                - Thanks!

George

[cimo]

hi i am interested on some of those drill bits contact me at cimo75@gmail.com

thanks

simone