Couldn’t find a perfect category for this so I put here since I have a X50. Onefinity may want to add a category for bits.
I recently upgraded to a ER20 collet spindle so can now use a 1/2" shank bit. Got thinking about buying a new spoilboard bit and started looking around. There are bits that have 2 or 4 cutters on the edge and there’s some that have 2 on the edge and 2 on the bottom. E.g the Amana RC-2250. Trying to understand advantages and disadvantages I went to their site for more info.
The Amana site says:
“Features unique 2+2 insert knife design that contains two cutting flutes and two up-shear scorers, which provide a smoother finish at the bottom of the cut than traditional two-knife style router bits. Great for surface planing.”
Sounds good, but then near the end of the page they say:
" Recommendations: For surfacing solid woods it is recommended to remove both bottom scorers."
What?? Lower scorers are great for surfacing material, but don’t use them on hardwood. Doesn’t seem like a good bit for hardwood then. I guess you could use them on MDF (unlikely to get a good surface on MDF though) or plastic.
Anybody here have experience with this type of bit? Is it worth it with hardwood? Do you leave the scorers on? Or is it better to go with a 2 or 4 flute edge only style bit? My use would be both for flattening the MDF spoilboard but also for planing hardwood.
you are aware that such bits can only be used to remove shallow depths, and that they are not able to plunge into the workpiece? Their use is rather limited. Usually when you work with a hardwood workpiece, you use endmills that are able to plunge, e.g. this one with e.g. 8 mm diameter. You can flatten a surface with a smaller bit very fast since you can use a much higher feedrate than you can with this bit.
If you think you need a surfacing bit for hardwood, I would follow their advice: Replace the cutters with #AMA-12 and #RCK-70 and remove the bottom scorers. The surfacing bits I know don’t have such bottom scorers.
Yup. Flattening the MDF spoilboard but also for planing hardwood.
You raise an interesting comparison. Using the same spindle, which is faster? A 1/4" end mill or a 2.5" planer bit? Is it even, a simple trade of IPM vs # of passes?
Interesting, when looking at the replacement cutters I see they consider the stock ones as being for MDF.
of course there exist use cases for such a surfacing bit, and then they will be faster (provided that your milling motor is able to deliver the torque needed for the diameter, the chosen cutting depth and the hardness of your wood). But the use of such a bit is very limited to that use. Regarding the high price, one should be sure to need one. With an endmill you can surface too, and do many other things.
I haven’t decided what to buy yet for additional bits. I have lots of 1/4" end mills. I also have an 8" joiner and 12.5" surface planer. So ‘planing’ on the CNC is really about getting to do wider pieces (which could take a long time at 1/4" passes) and doing them in place so doing a V-Carve will be working from the same plane to ensure the same DOC on the v-grooves across a piece.
I just came across these different designs and wondered about their pros and cons.
if you plan to use the CNC as a bigger planer for large flat workpieces, you got to think of how you clamp them. Did you already think of this? Usually large flat pieces can bow if clamped firmly from the sides. And usually if you are surfacing you don’t want to have clamps from above that limit the surface to be worked on.
And I am firmly convinced that the blue tape and cyanoacrylate method, which I already find weird, will scare everyone away at certain sizes.
I plan to do this only when I will be able to afford a large vacuum table.
With this, you should also be able to mill pieces thinner than 6 mm, which is impossible with a planer (and would usually require a wide belt sander or a drum sander).
I’ve used the blue tape and CA method for many projects. I’ve had boards curl up on me breaking the tape bond when stress is released in the wood through carving. I’ve used some double sided tape I had here but it was a real pain to get the backing off and I don’t think it held the material any better. I’ve recently bought 2 other recommend double sided tapes but I haven’t tried them yet. I do prefer to oversize and clamp when I can. Extra wood can be cut off later. If I really had to, I guess I could screw through to the spoil board, been reluctant to do that.
Do yourself a favor and get the RC-2255. I have used the 1/4" version for over a year and only had to rotate my blades once. It’s a beast! You will need hardwood blades, but it’s well worth the investment.
Aiph5u
(Aiph5u (not affiliated with Onefinity))
11
Hey Atroz,
that’s undoubtedly good to have.
However, to mill larger flat workpieces really thin (which is what I need), this would not be a secure clamping method, as it only holds at the edges. Thickness accuracy could suffer if the workpiece is thin and not held in the middle.
In any case, I’m already looking forward to the big vacuum table.
I can personally attest to burning up a really nice Whiteside 6210 surfacing bit (and the wood too) by trying to surface hickory and maple half a dozen times total. As @Aiph5u mentioned, these surfacing bits are really for things like MDF (spoilboard) or other softer materials at very shallow depths of cut.
Once I realized this, I switched to a less expensive SpeTool 1-1/4" Cutting Diameter Spoilboard Surfacing Router Bit which has replaceable cutters. It may be somewhat of a waste only getting used once or twice a year, but it does let me surface my Woodworker’s spoilboard in 20 minutes versus 1.25 hours with a 1/4" end mill, both at 160 ipm (4000 mm/m) and .01" (.25mm) cut depth. And, for RPM I find it does better at this feed rate when I slow it down to around 3 on the Makita dial which is ~15,000. Oh yeah, fair warning, these surfacing bits produce dust on cosmic scales. Think Milky Way amount of dust.
That’s yet another variation in blade position. I wonder what the advantage is of that layout instead? Looks like it can actually plunge in to wood. Seems to be tagged as CNC use only vs sled use on the others.