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sawdust535
03-12-2008, 04:10 PM
Just got my PRS Alpha BT32 running last week and broke my 1st bit. Need help on what I did wrong. Was using an Onsrud 60 deg. V-bit (included in Shopbot bit package)cutting red oak. Pass depth set in Partworks was set at 0.12, feed rate at 1.0"/sec, (thought I was being conservative), plunge rate at 0.8"/sec. I didn't set a pass depth in PartWorks, but I think the bit broke before the .25" depth. I attached the sbp. file.
Anything comments would be appreciated.
Thanks!
Bit Breaking sbp. File
Bit Breaking Cut File.txt (http://www.talkshopbot.com/forum/messages/26/Bit_Breaking_Cut_File-28790.txt) (36.4 k)
steve4460
03-12-2008, 04:22 PM
A freind of mine and I have the same bit , and when using it just once . The same thing happend to us . They must be faulty or something . Now that makes 3 bits . Anybody else had that happen to them ?.

Bot on
knight_toolworks
03-12-2008, 04:46 PM
mine never broke but since then I have went to the centrian bits. I have broken tips off when hitting nails but never the bit it's self. I carve wit a v a 3ips and the same plunge rate most of the time and .25 depth of cut. so your way under that.
sawdust535
03-12-2008, 09:36 PM
Thanks for the info. I'll call Onsrud to see if they have any info on these bits being defective.
Steve, do you have info on the source for the Centrian bits?
knight_toolworks
03-12-2008, 10:12 PM
how did the bit break? I mean what part broke?
http://www.centuriontools.com/
harryball
03-12-2008, 11:12 PM
Wow... Onsrud must have changed which 60 degree bit they include with the starter pack. Is it the large one with the 1/2" shank? I don't think I could break mine with a hammer. I'm sure I could shatter the carbide but the bit body is very sturdy.

/RB
steve4460
03-13-2008, 06:37 AM
We just brock the tip off on ours .after some realy light cutting.

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sawdust535
03-13-2008, 11:42 AM
Same here, just the tip. Actually, this is the second bit that broke. I ordered 2 more after breaking the 1st. Have one more to try out
knight_toolworks
03-13-2008, 01:12 PM
yes my tip on the onsrud vanished. the only tips broke on the centurian bits were when I dropped them or hit a brad or something like that. then it only costs 5.00 to have them sharpened.
steve4460
03-13-2008, 10:05 PM
So what is giong on here ? Are they faulty ?.
I thought that I had done something wrong , but from the looks of it , maybe there is something wrong. I bougt a 90 degree bit from onsrude that I had resharpend and the tip is still there I even used it to v carve letters in to aluminum only 0.0312 " at 0.5 IPS but that tip is still there .
So what's up with that ?.

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sawdust535
03-13-2008, 10:43 PM
I didn't get a chance to call onsrud today, but will call tomorrow. It seems a "bit" fishy.
sawdust535
03-14-2008, 04:44 PM
I spoke with Onsrud today and they said to get an authorization from the dealer to return the bit and they will have their lab guys look at it. They suggested anyone else with the same problem to do the same. Anyway, Onsrud said the feed rate for their 1", 60 deg V-bit (#37-82) should be 115 - 170 in/min at .25 depth cut (I was at 60 in/min, at half the depth when it broke).
Steve, thanks for the link. I ordered a 1/2" 60 deg V-bit from Centrion. Do you have a source for a 1" CD, 2 flute bit like the Onsrud.