Acrylic drill bit question

[BigB]

Wade,

Not trying to get into the itty bitty details, but what's the main differences between your acrylic drill bits vs the Abbeon acrylic drill bit?  My Abbeon drill bit is starting to show signs that it is needing replaced.  I like the way it works, but also have heard good things about your acrylic drill bits.

Thanks,
Brian

[Wade@WEBFoot]

I honestly cant say, cause Ive never held one of the other versions in my hand to look at....

Going from what Ive seen in pictures.... (so there is room for inaccuracies) here are the basic features

All the other ones over Ø1/2" are reground S&D drill bits... ie short flutes and a fairly long shanks.  Usually flutes shorter than the normal call blank being drilled.  The drills are also fairly short OAL.
They are ground to either a 60° or 90° point (aids in preventing chipping on exit)
They have a 0° rake - or close to that.
They have a standard point on them - ie center portion of the bit that doesnt cut anything also can be noted as web thickness - just smears its way through - as compared to a split point where the non-cutting area is reduced by a secondary grind and makes for less wandering and easier penetration.

On mine
They are reground jobber or longboy drills.  So the flutes are noticeably longer.  Where an S&D bit might have 2.75-3" flutes on a 5/8 drill, jobbers or longboys will easily have 4.5 or longer flutes.  And the OAL of the drill is an easy 7" or more.  (this can cause a space issue on really short drill presses or short lathe beds though)
Ground with a 90° point.  I felt 60° included angle was just not needed.
0° rake
Have a special type of point.  Acts like a split point, but is designed to also ease the transition from just the point cutting up to full diameter as the drill penetrates the surface as well as reduce required feed pressure.  It also seems to reduce the amount of heat created at the center of the bit because its not forcing itself through which helps to keep the bit cooler for longer drilling sessions.

So there are the basic differences based on what I have seen of the other bits in pictures....

I cant say there is anything majorly different from my bit to the others - for the exception of one major thing.  My drills were designed for the call maker, not someone working sheet materials.  All the others are designed for drilling sheet material or bars - not a 3-4" deep hole - as evidenced by the length of the drill and the length of the flutes.  Now I have had others say my bits were better, but I cant say first hand, as Ive never used any others.

Hope that answers your question... if I missed a key bit of info, just let me know!
Wade

[BigB]

The Abbeon drill bit I have has the same length of flutes as DeWalt drill bits that I am buying at my local farm store. 



Abbeon on the right, DeWalt on the left




How are your drill bits the same/different than the DeWalt drill bits?

Thanks,
Brian

[Wade@WEBFoot]

That Dewalt looks to be a S&D bit too. (S&D = Silver & Deming - is a type not a brand name)
(explanation of what an S&D Bit is (as well as many others):  http://www.globalspec.com/Specifications/Manufacturing_Process_Equipment/Cutting_Tools/Drill_Bits )

Flute length on a 5/8 jobber is (give or take a tiny bit) 5-3/16" and OAL is 7-1/8"
Flute length on a 5/8 S&D is (give or take a tiny bit) 3-1/8" and OAL is 6"

So - aside from the obvious differences between a drill bit ground for acrylic and the Dewalt standard point (S&D in this case)...  mine are longer (bout 1-1/8"), with longer flutes (bout 2-1/8"), and of course the different grind on the point. 

If youre looking at reduced shank bits, for all sizes except 7/8" - they are jobber length drill bits (longer with longer flutes) and I cut the shank down to 1/2".  On the 7/8" reduced shank, it is a S&D bit (6" long and shorter flutes with a 1/2" shank) because of cost.  A 7/8" jobber is a LOT of metal and an expensive bit - and since people usually only drill an inch or so deep at 7/8" - there was really no need for a 9" long drill bit with 6" flutes - not to mention not as easy to get a hold of as a S&D bit.

Does that help any?
Wade

[BigB]

Thanks Wade.     That was an excellent description and helped me out.


Brian

[Wade@WEBFoot]

Glad it did...  Hope I didnt give away my super duper double probation secret grind :D bawwhahahahahahaa