Favorite insert spoilboard / slab surfacer?

[SarahRay]

In the market for a new flycutter, preferably one with inserts that I could also use for flattening slabs. Got any favorites?

[Brady Watson]

I like the Amana Tool RC-2250

-B

[coryatjohn]

My favorite is this one:
Magnate 2706 Surface Planing Router Bit - 2" Cutting Diameter

No inserts but the 2" cutting diameter makes the work go a lot faster. It's really good for flattening out slabs too. A bit pricey perhaps.

[steve_g]

I’ve got both the magnate 2706 and the Amana RC-2250.

We were surfacing many, many pecan slabs. The Amana 2+2 insert design was indispensable for this chore! Or, if you ever get tasked with surfacing a stringy species like Cottonwood, you can’t do it without the vertical cutters of the 2+2 design. The best feature of an insert bit is if you hit a nail, you can have a fresh edge in no time!

The magnate bit does fine resurfacing the spoil board…

SG

[dlcw]

Concur with Steve_g. I've got the Amana also and have been using it for slabs, large signs spoil board and sacrificial boards for 9 years. Couldn't do what I do without it.

[adana]

Hi all! I've been off the forum for a long time, so hello again, hope all's well with y'all.

I've used that Amana RC-2250 mostly for spoilboard flattening and found it works a lot better (quieter, smoother result, inserts don't gum up) when I use it with just the side inserts, leaving off the low flat ones. Has anyone else experienced that? Are there applications where I'd be wise to re-install those other two inserts?

(editing to add image of tool w/o lower inserts) (also how do I keep the image from being absurdly huge?? Sorry about that!)


Using that tool (also open to other tool ideas), I'm looking for recommendations for flattening areas of wood parts (the usual suspect hardwoods - cherry, maple, walnut, beech):
- what are fave feeds/speeds?
- what's the best amount of stepover?
- are with-the-grain passes always best? Is there an advantage to conventional vs. climb cutting?
- assuming you'd do a rough cut to near thickness, then a smoothing cut, what are generally successful values for those steps?
- is there any kind of post-cutting abrasive smoothing you can do while the part's still on the 'bot? Like, some kind of Roloc or whatever that you could chuck up into the spindle and repeat the same final toolpath?

I've been getting a lot of striping, with "micro-tearout" lines that required significant sanding to ensure there are no telltale remnants after finishing.

Thanks in advance for any and all help! This feels like an area where I'm not yet using the machine to its full advantage.

[Brady Watson]

They do perform better when you pull 2 of the 4 off...So you're on the right track.

The best performing 'flattener' that doesn't leave lines (as long as your Z axis is 100% correctly aligned!) - is a shop-modified MLCS P11-1706 for a whopping $17...Get yourself some diamond hones (on a plastic stick - set of coarse, med, fine, like these) and knock down the very outer edge of the bit to recede the sharp pointed edge. Works a treat. When it gets dull, hone the cutting edge. You can speed up knocking the corners down with a dremel/grinder and flap sander disc. As long as you don't take off too much, you won't throw it too far out of balance.

FYI - your Amana inserts can be sharpened on those hones as well...lay it flat on the table and rub the insert back and forth (wet with water) about 10-20x.

In my experience, flattening hardwoods, you never want to do an offset/spiral toolpath. Raster back and forth parallel with the grain. Toggle off the perimeter 'first/last' option in the pocketing toolpath too...I used to do large butcher block resurfacing this way for chefs.

-B

[adana]

Awesome, thanks Brady! I'll get those hones and cutter on order immediately. Some followups:

- what's the tradeoff between the 1.5" and 2" diameter cutters? I'd have assumed larger's better? Increases the amount of the tip's arc that passes close to tangent?

- where should I look for the best process for getting my Z axis 100% correctly aligned? (embarrassed to ask but hey, here we are :-)

- Just so I'm clear before I get to grinding, are you saying add a radius to the lower outside corner? Is this like a 0.010"-ish radius or more dramatic? I'm imagining the optimal might be related to wood grain 'resolution'
Thanks again!

[Brady Watson]

The trade-off is that if your Z is out one way or another, it will be magnified with a 2" bit, compared to the 1.5" one. Plus, you'll have a lower max RPM with the 2" and it will take more hp to turn..The 1.5 is fine.

You will get varying ideas about how to true up the Z. This varies by machine model, but I've always used a dial indicator to verify parallel travel along each face of the Z axis along its stroke. If you have a PRS, adjust your lower v-roller bearings first...not too loose, not too tight. A dial indicator will measure displacement. It is the king of measuring tools and tells you where it needs to be adjusted...no squares or bent coat hangers required.

Less useful in my opinion than a $30 indicator/magnet combo is this tramming tool from Edge - You spin it around and adjust as needed that way, but your spoilboard/table could be messed up or warped, so I prefer just a dial indicator. Plus it's $100...but looks real purdy.

Yes - just a small radius on the 2 outer edges only AND only raster parallel to the grain.

-B

[adana]

Oooo that thing sure is purdy! Looks like they make a lot of purdy tools - fun site. But I own an indicator already and will be happy to turn to it for guidance with my Z parallelism.

Yep: it's a 2008 PRS Alpha 48x48, so I'll do said v-roller bearing adjustment.

Roger, small radius, raster parallel to grain... I'm feeling optimistic about this whole thing! Many thanks, once again.