Perfect Plank Pine

[Todd Wertz]

Hi All,

We tried running perfect plank pine for a pattern. Every time it moved onto a vertical edge it chattered. We used a .5" 4 flute ball at 18000 RPM and ran it at 300 ipm. We run this same scenario with mahogany and never have any trouble.

Thanks

Todd

[Kannon]

Todd..

might want to add your question to the woodworking forum here also.

[Westgate Hardwoods]

Todd,

 

Depending on the thickness of the material, you might try slowing down the feed rate and or try a 3 or 2 flute cutter. At that feed rate with 4 flutes your not allowing the chips to get out. You shouldn't be seeing dust from your cut, but rather small chips.

[Todd Wertz]

Why would it work in mahogany and not in pine?

[machtek]

I run a .5 3 flute at 22000 rpm 650 ipm

 

Dennis

[Greg VN]

I'm not familiar with perfect plank pine but I know most woods. When you say verticle edge are you talking about the side grain or end grain?

 

Just trying to understand what you are talking about - maybe I can help.

 

For wood 2 flute cutters seem to work best from my experience. The grain in pine is harder than the areas between the grain patterns and the grain changes direction frequently. When the rotation of the cutter is rotating into the grain you will be be creating some chatter and are likely to get some splintering of the wood. Mahogany the wood is more consistant in grain and there are not the areas of different hardness.

I recommend that you slow down the feed rate.

[Todd Wertz]

Dennis, is that surfacing or just a single linear cut?

[Todd Wertz]

Greg, Perfect plank is essentially prefab butcher block.

[Todd Wertz]

http://www.freemansupply.com/PerfectPlankPine.htm

[Trevor Bailey]

if you are taking heavy cuts also, something more than the radius of the tool, look into using "corn-cobb" cutters. mush less tool pressure, finer chips, less heat. you can find many cutters that will have jagged serrations even on the radius of the ball cutters.

 

i use vortex cutters with great results.

 

Moderators....move this to the Woodworking Forum please.

[Greg VN]

You must be talking about cutting the end grain. Are you using the ball cutter to engrave a pattern into the surface or are you cutting around the edges.

We make parts for stairs. When ever we cut around the sides of a part and get to the end grain we frequently have a problem with tearout and chatter. Usually it is a problem with a profile tool not so much with straight cutters. If you can increase the diameter of your ball cutter that will help with vibrations.

 

I have noticed that if you are cutting for example a circle when the cutter goes around the end grain and it tears a little and you go around the same path again with out stepping into the wood (thinking it might clean it up) it can make the part worse.

 

Unfortunatley it is a problem with some woods.

I see it a lot with harder woods or woods with hard grain. Mahogany happens to be one of the better woods.

 

I don't know of a perfect solution for this problem sometimes it can be helped with having cutters with LH rotation in some areas and RH rotation in other.

[Todd Wertz]

I apologize, we are cutting 3d patterns. This means we are cutting every possible direction. We rough out the pattern with a vortex roughing bit and go back in with a Garr ball endmill and surface the entire pattern. We use a .02-.03 stepover, so it's not cutting very much. Also, I should mention, we don't have trouble going up the other side. it is only on one side of the pattern. If you picture a bowl cut into a block, we would only see this on one side of the bowl. This is particularly interesting because we cut two directions.

[Greg VN]

That explanes it. In the areas where you are seeing the tear out you are rotating the cutter into the grain and it is pulling chuncks out (for lack of a better term). The way aroind this is to have a cutter that rotates in a direction that is favorable to the grain direction in the problem area.

[cajahawa]

I've cut a lot patterns out of pine perfect plank. I guess the best advice I could give, is get the spindle as fast as it will safely go. Do not run zig-zag. And if possible, run the ends first. But in my case that usually wasn't practical. You will get chip out regardless. Putty can be pretty useful in that case. Keep in mind that it may be more cost effective to pay the extra to use mohagany it has a tighter grain. so it sands up better and really does make a much better pattern. Best of Luck

[cajahawa]

I almost forgot, run climb not conventional.

[Ployd]

What about using Medite or MDF?

[Todd Wertz]

We have used High Density Fiber Board but it pulls apart under the strain of thermoforming. We do use a lot of Mahogany, however, we were looking at cutting some costs: not sure it's worth it.

[TKDBB]

Pine is softer and weaker than mahogany. Use lighter cuts and faster feeds. Consider using Ren Shape planks. Costs more but cuts better. No grain problems.

[KalCam]

Todd,

You can coat your High Density or more common MDF patterns with baby powder during forming. Just pour some in a shop rag and pat down your pattern, remove excess and your baby is good to go

[Todd Wertz]

We use quick poly to coat our patterns, and silicone mold release or baby powder for eject. Even with all of that, 2 degrees of draft and no undercuts we've ripped them in half. Ren takes us out of our market. Most of the time, aerospace are the only customers who will pay for it.

[Todd Wertz]

Thanks a bunch for your help folks! Lots of good advise here. However, I think I've decided to give up on Pine. We'll stick with Mahogany.

[MATT Q]

Trupan mdf

cut the pattern then we seal it, hand sand then coat with a heavier sealer and we can get about a dozen pulls if we are lucky. not so lucky with poly

[Sandybar]

I cut a lot of what I call Pattern Pine. I have my best luck using Down Shear cutters for roughing and then us a carbide bull nose for 3-D finishing. Also I have used plain old roughing "corn cobb" type cutters too, they work great.