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View Full Version : Can I use router bits in a shop bot?



skintigh
11-09-2018, 05:08 PM
I have to make a ton of balusters, each with 4 chamfers 1-3/6 inch wide and deep. Can I use a big router bit in the shop bot?

I've used this bit on my router:
"uxcell 1/2 Inch x 1-1/2 Inch Carbide Tipped 2-Flute 45 Degree Chamfer Router Bit Cutting Tool"
It has a 1/2" shank, 1.5" wide chamfer, unknown chip load. Can I use that on a shopbot? I've used it in my Bosch router quite a bit and I think that is higher than 18kRPM.

What about plunge cove router bits? like a 1/2" plunge cove? Or even bigger? Do I just start slow and test speeds? Thanks!

Brady Watson
11-09-2018, 05:16 PM
You can use any bit without a bearing. Instead of the one you show, use this one (https://www.amazon.com/Cutting-Carbide-2-Flute-Engraving-V-Groove/dp/B01N4Q3CMH/ref=sr_1_1?ie=UTF8&qid=1541801631&sr=8-1&keywords=uxcell+1%2F2+Inch+x+1-1%2F2+Inch++90+Degree&dpID=41WA4MoV2cL&preST=_SY300_QL70_&dpSrc=srch) It will do the same thing without the danger of breaking the bearing off.

Bit geometry doesn't matter...no bits with a bearing on it. If you can't find one, remove the bearing, grind off the boss all the way down to the nub and program it so it NEVER plunges straight down. You'll have to lead in to the cut from the side.

skintigh
11-13-2018, 02:47 PM
Oooooooooooooooooooh I completely forgot about the bearing on it, very good point! The bit you linked is so cheap I'll buy that if I end up using the CNC rather than grinding down my old bit, thank you for your answers!

But hypothetically if the bit was $1000 or something, is it inherently dangerous to to use a bit with a bearing even if you lead in from the side and the bearing doesn't touch? Or does the danger come from cutting too far and damaging the bit or the CNC machine itself? I used to not worry about cutting too far and assumed everything would go as planned, but lately I've had bad luck and broke some bits (user error? machine error?) so I won't dare risk it with a bit this big.

khaos
11-13-2018, 02:53 PM
Hypothetically, don't use the bearing. The danger is breaking the bit, possibly damaging your machine and letting blood out of your blood bag.

Brady Watson
11-13-2018, 03:48 PM
...is it inherently dangerous to to use a bit with a bearing even if you lead in from the side and the bearing doesn't touch?


The danger is breaking the bit, possibly damaging your machine and letting blood out of your blood bag.

Gotta protect your bag...:)

The ONLY time I've used a bearing bit on one of these machines is manually...as an inverted router table. You need to know what you are doing...so me mentioning it isn't a recommendation.

Imagine the bearing bit being run in a straight line and the material is slightly warped - it doesn't take much side load to snap off the bearing boss and throw shrapnel at 'bag level' across the room...and for what? To save a few bucks? How much is YOUR bag worth?

There's ALWAYS a way to do what you need without using a bearing bit. Even funky shaped profiles can be done via 3D or by using a series of shaped cutters - or custom ground ones to get the job done.

Not sure if you are planning on using the CNC professionally, or if it is just a hobby...but there are gains to be made by buying the correct tooling & quality tooling not sold on Amazon...A word to the wise is sometimes sufficient these days.

Make sure you're wearing safety glasses...cup optional.

skintigh
11-16-2018, 04:29 PM
LOL, yes, more good points! I've been using MDF so much I forgot trees don't grow in perfect rectangles.

Don't worry, I won't use a bit with a bearing and damage any bags...