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!)
http://www.talkshopbot.com/forum/attachment.php?attachmentid=31938&stc=1

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 (http://www.eagleamerica.com/product/vp11-1701/pc_-_straight_bits) for a whopping $17...Get yourself some diamond hones (on a plastic stick - set of coarse, med, fine, like these (https://www.amazon.com/dp/B000S5SD9M/ref=psdc_553346_t2_B002RL83DQ)) 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'http://www.talkshopbot.com/forum/attachment.php?attachmentid=31939&stc=1
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 (http://www.edgetechnologyproducts.com/pro-tram-system-01-000-10-000-09-000/) - 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.

[bill.young]

Amana makes a surfacing bit with replaceable inserts, their #2242, that uses inserts with 2 radiused corners and 2 with square corners that you can rotate depending on your use. It's pricey at $150.

[adana]

Thanks Bill! That’s a very interesting option that would take some of the pressure off my DIY bit modding skillz. But wow, pricey for sure.

So (just so I’m certain) does that mean there aren’t radiused inserts that are compatible with the 2250 I already own?

[Red F]

Brady, I’m trying to picture how a dial indicator can be used to true up the z-axis without something to offset it like the aforementioned shiny object.
Would you mount it to the table and chuck a pin into the router? Then run the router up and down?
Thanks

[coryatjohn]

If you search Google for the term "tramming" and especially look at the image results, you'll get your answer.

[Brady Watson]

Brady, I’m trying to picture how a dial indicator can be used to true up the z-axis without something to offset it like the aforementioned shiny object.
Would you mount it to the table and chuck a pin into the router? Then run the router up and down?
Thanks

Red,
A dial indicator will report displacement - this means that if you move in a parallel direction to the fixed indicator, it will report any deviation from your set zero point, along the length of the stroke. This means that if your Z axis is out, say 1°, and you set the indicator to zero at either the bottom or top of your Z stroke length, the indicator needle will move one way or the other, reporting the displacement from your set zero point. The numbers on the indicator are irrelevant - because you are shooting for zero movement of the needle along the entire stroke of the Z axis.

The attached drawing (I'm going to hang a copy on the fridge :p ) shows how an indicator may be used on a ShopBot (any model - but mounting options will vary) to check parallelism. You can think of parallelism as 'squareness' where a framing square against the spoilboard is impractical or just not accurate enough to get your Z dialed in. It is possible to get your Z axis well under 0.001" parallel in both directions using a cheap indicator. Some models are easier than others in terms of having a good place to magnetically stick the indicator base - however, you can also use a clamp or any other means to mount the indicator. In some cases, just a piece of steel bar/strap with some holes drilled in it to mount to the aluminum extrusions is very helpful.

31940

Avoid using the router or spindle body as a reference - I have found them to not be true. Some of this is because of how it is mounted and some because of the body itself. When I was setting up new ShopBots, I always loosened the spindle bolts that held on the spindle mounting plate and then MADE SURE it was as parallel as I could get it to the spindle itself. I chose either the left or right side of the spindle and forgot about the other side - then I'd pop the 'tail' out of the back of my 6" digital caliper and checked between the plate and the top and bottom of the spindle, until both measurements were EXACTLY the same. This is a little bit of a pain sometimes because the countersunk screws that hold the spindle to the plate can influence the distance and walk the spindle over while tightening them down...so you have to do some back and forth - but only once. Just set it...and forget it! The aligned plate gave me a pretty decent edge to check side to side parallelism when adjusting the Z (on a PRS or DT) in the Y direction. Deviations in the X direction are more complicated on a PRS because (and this is NOT that uncommon) - the gantry beam is rotated from the vertical a small amount - which becomes large at the bottom range of the Z axis because of it. On a PRT, a rubber mallet will knock that Z the small amount needed before you king kong the bolts tight on it.


I said the dial indicator was the king of measurement tools because it is so versatile. It can be used to check parallelism/squareness, runout of a shaft, to position things perfectly concentric in a lathe (although a test indicator is better for this), you can use it to check your tablesaw fence to blade parallelism to see if that is what's binding your cuts, and to check that your dual compound sliding chop saw is running true when it's set to the 0 mark. You can use it to check that your part or fixture (like a milling machine vice) is square/parallel to the spindle, and to also check for highs/lows in your table. You can also use it to test machine deflection and gantry sag (as you press down lightly on the YZ car), and to check for slop/backlash in your gearbox motors when the tool is powered on and at a rest. The list goes on...For times when you can't get a square in there...or you don't have a square/flat/true reference to anything - the dial indicator is the go to tool.

-B

[Burkhardt]

My poor man's version of that shiny tramming gadget. With almost 20" sweep diameter it will detect even very small spindle misalignment. It is just a 1" x 1/4" aluminum bar, twisted 90 degree in the vise with a large pipe wrench. There is a 1/4" or 1/2" decapitated bolt shank for the collet and a cheap dial indicator on the other side.

I clamp that aluminum square tube on the table to get an average across the uneven crowned table extrusions. For a newly skimmed spoilboard table that would probably not be necessary. The indicator must sweep freely without pushing on that lever.

31941

[Gary Campbell]

Brady alludes to it, but I would like to emphasize this point. My method is to surface the table first. This must be done! (even is spindle is out of tram) Then I place a 12 by 16 piece of aluminum that has been surfaced on both sides. This gives a qualified surface to ensure that whatever method you use your reading actually means something. See pic below.

http://www.talkshopbot.com/forum/attachment.php?attachmentid=31942&stc=1