WEBFoot Acrylic Drill Bits
Suggested Feeds and Speeds:
Generally the larger the bit the slower you should go - both in RPM and in the rate of feed of the bit into the material. Acrylic is very "touchy" when it comes to heat and aggressive cutting. Though in theory, one should be able to turn smaller bits faster than larger bits, one must always keep in mind heat build-up and lubrication. The following chart is a guide to help get you close - you will notice we recommend slower RMPs than tested - and the ability to run faster has more to do with your setup, ability, and process than the drill. From there, you will want to tailor the feeds and speeds to meet your personal criteria, preferences, and equipment abilities. These rates are based on drilling from solid material. If you have a pilot hole in the material, you may be able to increase the feed speed and or RPM.
Drill Bit Size Range | Sugg. Starting RPM | Suggested Feed | Peck Drill Depth |
15/64 - 3/8 | 400-600 rpm | 5-10 seconds per 1/4" | 1/8" |
1/2 - 9/16 | 300-400 rpm | 7-12 seconds per 1/4" | 1/8 - 1/4" |
19/32 - 5/8 | 200-400 rpm | 10-12 seconds per 1/4" | 1/8 - 1/4" |
3/4 - 7/8 | 150-200 rpm | 12-15 seconds per 1/4" | 1/8 - 1/4" |
What the testers had to say:
Tester #1 (please note the fast spiral bits are not being produced as the other bits out performed them)
Testing the new Webfoot Acrylic Drill Bits
1. Testing Parameters
A. Test Material - All drill bits were tested using 1 3/8" Cyro clear cast acrylic.
B. Test Machines - All bits were tested on these three machines:
1) Craftsman 16 speed drill press (well worn)
2) PSI Turncrafter Pro Mini Lathe ( almost identical to the Jet Mini)
3) Bridgport Manual Vertical Milling Machine
C. Feed Rates - Done manually to show results of use on manual machines.
D. Lubricants - All drills were lubricated and cooled using WD40.
E. Test drills - The following were used as part of this test:
1) Webfoot 19/32" Fast Spiral Acrylic Grind (edit: this model is not being produced due to inferior results)
2) Webfoot 5/8" Straight Shank Acrylic Grind
3) Webfoot 5/8" MT2 Acrylic Grind
4) Harbour Frieght 1/2" bit for Acrylic, Glass, Ceramic
5) 5/8" Jobber bit hand ground to 90 degrees by Bob Eames
2. Test 1 - Craftsman Drill Press, 740 RPM
A. Webfoot 19/32" Fast Spiral Acrylic Grind - Started bit, and kept the hole filled with WD40. Drilled 1/8" at a time, clearing chips after. Drilled a good straight hole, no crazing apparent. Some wiping shows in hole, but get's better near the bottom of the hole ( probably caused by to fast of feed rate, or not enough cooling). Bit doesn't get overly hot durring drilling, but does have some problems ejecting the chips without being removed from the hole. Hole is accurate, and could be easily sanded and finished.
B. Jobber Bit, hand ground by Bob Eames - This is the bit I normally use in lieu of a sharp bit from Abenon. It is hand ground with a 90 degree point. Started bit, and kept the hole filled with WD40. Drilled 1/8" at a time, clearing chips after. Drilled a good straight hole, no crazing apparent. More wiping than the webfoot drill, probably caused by the inconsistency of the hand grinding. This is my standard drill, and was some wear, so the hole is accurate, but would take significantly more sanding to finish than the webfoot drills.
C. Harbour Frieght 1/2" bit for Acrylic, Glass, Ceramic - This bit doesn't clear chips well at all, but got through without any crazing. Hole is not overly accurate or straight, due in large to the design of the bit itself. It was much slower to drill to depth than any of the other bits, but would suffice for holes through thin plate where accuracy was not imperative.
D. Webfoot 5/8" MT2 Acrylic Grind - Mounted into my drill press in lieu of my drill chuck. Started bit, and kept the hole filled with WD40. Drilled 1/8" at a time, clearing chips after. Drilled a good straight hole, no crazing apparent. Less wiping than any other drill tested in the drill press. Seemed to do a better job of ejecting chips than the other bits, giving a clean, accurate hole that would be the easiest of the bunch to sand and polish.
Conclusion, Test 1 - Although all of these bits are far superior to standard jobber bits for drilling holes in acrylic, all of the webfoot bits tested had superior finishes in the holes. This would equate to less sanding to polish the holes on transparent acrylics. I could not test the straight shank 5/8 from webfoot, due to the limitations of the chuck in this drill press. I ran the MT2 bit all the way through the test piece, and out the angled side of the acrylic with little to no chipout, something that wold be impossible with a standard jobber bit.
3. Test 2 - PSI Turncrafter Pro Mini Lathe
A. Using 1 1/2" black cast acrylic rod from Delvies, I ran a few holes with the Webfoot 5/8" MT2 Acrylic Grind. I center drilled the blank, and started the drill. I drilled to the depth of my tailstock 1/8" at a time, lubricating with WD40 after clearing the chips. I was very satisfied with the good clean hole I got from the bit, but noticed a defined ridge after I moved the tailstock forward to complete the hole. I attribute this to the sloppiness of the tailstock in their type of lathes rather than the bit itself.
Conclusion Test 2 - Although I only drilled 2 holes on the mini lathe, it was apparent to me that the bits would hold a tighter tolerance than the tailstock would allow. Either of the blanks that I drilled on the lathe would be easy to finsh out, but the ridge from moving the tailstock is one of the reasons I avoid drilling on the lathe. Another reason I avoid lathe drilling is the lubricant that gets thrown everywhere, making a mess. These shoud fit the bill nicely for anyone looking to drill on the lathe, as the hole was accurate for the most part.
4. Test 3 - Bridgport Manual Vertical Milling Machine - 630 RPM
A. Webfoot 19/32" Fast Spiral Acrylic Grind - Mounted the bit in a 5/8 collet to ensure accuracy. Started bit, and kept the hole filled with WD40. Drilled 1/8" at a time, clearing chips after. Noticed right away that the bit prefers the slower speed. Much less wiping apparent, possibly due to the accuracy of the tight tolerance spindle of the milling machine. Good, clean hole with a very small amount of wiping. I did notice that the chips didn't seem to eject well, which could add to the wiping problem I'm seeing in the holes.
B. Webfoot 5/8" Straight Shank Acrylic Grind - Mounted the bit in a 5/8 collet to ensure accuracy. Started bit, and kept the hole filled with WD40. Noticed right away that the bit prefers the slower speed. Almost no wiping in the hole, by far the best holes produced in this test so far. Chips were cleared at regular intervals, about every 1/8". Drilled fast, making great headway with a superior finish in the hole. Accuracy of the holes were outstanding.
Conclusion Test 3 - These bits really shined in this setting with spindle speeds in the 600 RPM range. Wiping was very low, with the 5/8" straight shank leaving the best holes of the test so far. These holes could easily be sanded and polished very quickly, and the 5/8" can produce holes that could be cleaned and immediately flame polished with excellent results. Neither bit seemed to get hot during this test, indicating that the speed was very close to optimal range for these bits with this lubricant. These holes were the best finish I have ever encountered for any drill bit through acrylic, and are as good in my opinion as the finish left from operations on a CNC using a boring bar.
5. Test 4 - Bridgport Manual Vertical Milling Machine - 1115 RPM
A. Webfoot 19/32" Fast Spiral Acrylic Grind - Mounted the bit in a 5/8 collet to ensure accuracy. Started bit, and kept the hole filled with WD40. Drilled 1/8" at a time, clearing chips after. Wiping worse than the slowere speeds, but holes still passable. Makes goos headway through the material, but the finish suffers.
B. Webfoot 5/8" Straight Shank Acrylic Grind - Mounted the bit in a 5/8 collet to ensure accuracy. Started bit, and kept the hole filled with WD40. Drilled 1/8" at a time, clearing chips after. Still good finish on the holes, but more wiping apparent with the higher speed.
Conclusion Test 4 - Although these bits were not designed to be run a the speeds of this test, both bits proved to produce good holes with a minimum amount of defects. With a steady flow of coolant, it is very possible that these bits could provide outstanding holes with a controlled feed rate at these speeds.
"I was tester number one, and I got to bust them up before anyone else! I've been running Abbenon bits for a while now, but I'll be buying my next set from Wade. These are the shizzile! I have to run them just a bit slower than the Abbenon bits (about 600 RPM for the 5/8" bits) but the hole finish is amazing! It will cut your sand and polish time in half (actually cut mine by 3/4). I'll dig up some pictures of some of the holes here in a bit an post up."
Tester #2: (Test 1 & 2 were for the fast spiral bit that proved to be less effective and is NOT being produced)
Acrylic drill bit test. Used normal downward force when drilling. Drill approximately 1/4 “then would retract and apply more coolant with an “oil can” or aerosol can and also clear chips.
Test #1
19/32 bit (fast spiral)
ATF Type A used as coolant
1.5” OD Blue Pearl Acrylic 2” long with a rough angled cut on exit end.
675 RPM Bit cut very sharp. Exit hole had one chip out that may have been from too much force when bit exited piece along with the angled end of piece. Cut piece in half length wise and could see visible scaring and light crazing.
Test #2
19/32 bit (fast spiral)
WD40 aerosol as coolant
1 3/8” OD Clear Acrylic 2” long clean square cuts both ends.
675 RPM Very smoky from the WD40. Cut piece in half lengthwise and could see visible scaring and light crazing. Would take wet sanding then polishing to clean up. Very clean exit hole.
Test #3
5/8 bit
WD40 aerosol as coolant
1 3/8” OD Clear Acrylic 2” long clean square cuts both ends.
675 RPM Smokey due to WD40. Light cross hatch in hole. Would only take light wet sanding and polish to clean up
Test #4
5/8 bit
ATF Type A as coolant
1 3/8” OD Clear Acrylic 2” long clean square cuts both ends.
675 RPM Very light cross hatch. Would probably clean up with #3 Novus and the polish. Best results yet.
Test #5
5/8 bit
ATF Type F as coolant
1 3/8” OD Clear Acrylic 2” long clean square cuts both ends.
1500 RPM Good hole until last 3/4” of part. Then bit grabbed part at exit and created chip out and small cracks. Just too many RPM with applied force.
Test #6
5/8 bit
ATF Type F as coolant
1 3/8” OD Clear Acrylic 3” long clean square cuts both ends.
490 RPM Very minimal cross hatch. Did not cut piece but rather polished outside of part. Can see that only plastic polish would be needed to clean up hole. Part lightly chipped due to bit grabbing upon exit.
Final test piece and best out of all variables that were attempted.