cherry tearout

[scottp55]

Have run this same program/same bit (4 ash/4 hard maple) with no problems. Run bowl bit first(shallow rough passes/full depth skin pass). Pockets shown(waiting on 5 larger bits) were cut with Onsrud .25down. Profile pass first.
Ran 6 cherry yesterday, identical bit/path and had tearout where it was clean and crisp before. Ran climb cut on all. I've run cherry before 2D and 2.5D and never run anything but climb cut. All 6 of these were important samples to buyers of course:( Does cherry like a conventional cut for this kind of cut?

[garyb]

It' because you are running in a climb with the downcut, should be conventional.
You were lucky with the ash and maple ;)
Gary

[scottp55]

Thank You Gary, Never did get back to you, sorry,out straight.

[srwtlc]

Conventional or climb, you're likely to blow off those corners each way with your cherry blank because of the unsupported edge/end grain (vertical orientation of your blank). The ash and maple, you have the grain running horizontal and don't have the same situation, thus the clean cut. Conventional cut is my preferred direction for this kind of stuff.

Another tip for inside corner profiles is to slightly radius them or at least set the "corner" setting for profile toolpaths to NOT have "sharp external corners". This way the tool kind of rolls around the corner instead of a stop/go sharp corner. The resulting finished cut shape is the same though. I have had good results by radiusing any sharp corners. It doesn't take much of a radius and is not noticeable in the finished cut.

[scottp55]

Thanks Scott, Makes sense. Such a rush job(Just overnighted College ones 20 minutes ago) I had tunnel vision on maximizing production and not wasting wood , I forgot about the wood! Unlike me.
Time for wider stock. Rescued them though.

[Bob Eustace]

Conventional or climb, you're likely to blow off those corners each way with your cherry blank because of the unsupported edge/end grain (vertical orientation of your blank). The ash and maple, you have the grain running horizontal and don't have the same situation, thus the clean cut. Conventional cut is my preferred direction for this kind of stuff.

Another tip for inside corner profiles is to slightly radius them or at least set the "corner" setting for profile toolpaths to NOT have "sharp external corners". This way the tool kind of rolls around the corner instead of a stop/go sharp corner. The resulting finished cut shape is the same though. I have had good results by radiusing any sharp corners. It doesn't take much of a radius and is not noticeable in the finished cut.

What an excellent strategy Scott - thanks!

[srwtlc]

Ah, some creative sanding. Been there done that. ;) Nice job!

After seeing the extra elements in the design, the vertical grain orientation looks better, but is going to be troublesome. May take some creative toolpathing to alleviate the problem. Might try the bowl bit for the whole pocket first and give some radius to those corners and then follow up with the straight bit to take out the fillet and make your flat portion. The radius should backup that end grain then.

Not that it will help here, but another tip/trick for pocket profiles is to leave an allowance on the pocket and clean it up with a profile pass while using the ability to designate your start point and also use a slight circular approach/depart to not make a divot or burn mark at the start. If there's not a node where you want to start, insert one there and make it a start point.

[scottp55]

Yeah Scott, But I've got the Bowl bit running first as a "profile on line" and that "little line" followed the pocket line. Redrawing now using Brady's 1/2" BN strategy so I can insert radius. Using 5.25" stock full 24" width gives 9 to a batch vs. 8 vertical, but it does look better with grain vertical. This batch Tung/polymerized linseed/poly/citrus/wax came out well with a long open wet sanding 320G time. Think it's a keeper if it builds fast. Back to the drawing board, Got to get pocket time and finish better(pockets a pain to sand).:)