Has anyone ever cut HDO

[fleinbach]

I just tried to cut some 1/2" HDO and it was not much fun. A 1/4" Onsurd upspiral at 2 IPS and 13,000 RPM produced lots of smoke. I did not have time to make anymore tests or try differant speeds so I thought I would see if anyone else has ever cut any of this stuff.

[mrdovey]

Frank...

I've cut it with a 3-flute solid carbide end mill at 1-1/2 in/sec and 14,000 RPM.

Make sure it's well secured for cutting andd use only really sharp bits. I found I needed to change bits somewhere between 200' and 300' of cut.

It's good, sturdy material - but it doesn't treat router bits very well.

I spent my day routing aluminum with the same 3-flute bits - it's much better behaved.


...Morris

[fleinbach]

Morris,


How deep were your passes?

[mrdovey]

I think I was using 3/8" passes for profiling and peck drilling in 1/8" steps. I'd need to check the part program at the shop to be sure - it's possible that I was cutting 1/4" passes.

I've only ever had smoke when I used really cheap (not sharp!) router bits.

...Morris

[donchapman]

I've successfully clean cut 1/2" MDO with a 1/4" solid carbide compression bit using multiple shallow passes and about 100ipm feeds.

[donchapman]

Correction: I just remembered it was a downcut spiral that finally cut clean. The part near the tip of a compression bit acts like an upcut bit , so it does not work well in matierials prone to uplift tear our and requiring stepped passes.

[fleinbach]

Don, Thanks for your input but I'm not having a problem with the quality of the cut. My problem is with how difficult it is to cut. This stuff is way different then MDO. I cut lots of MDO with a hand router when I was making ribs for satellite dishes back in the early 80's and never realy considered it a problem.

It seems to me there is something in the resin they used that caused all the smoke. I say this because it would cut one area of the sheet with no smoke and then another area would smoke significantly.

[rick_woodward]

I havent heard of HDO . At first I thought you meant MDO, now I think you mean HDU. What exactly is HDO ? Thanks, rick

[donchapman]

Sorry, Frank, I thought you meant MDO.
I have no experience with HDO.
Like Rick, I haven't heard of HDO.
My experience is with MDO, MDF, HDU, regular plywoods, solid woods, and hardboards.
Since I can cleanly route those materials including Ipe, which is an incredibly hard and dense wood, my best guess is that the material you are having trouble routing contains abrasive glues or abrasive woods or contaminants such as some which have silica. Try greatly decresing feed rate, rpm's, and depth of cut and see if that works, then gradually increase each until it doesn't. Ususally the main reason for burning bits is too high rpm so that you lose the cooling effect of the chips. Sometimes a slower rpm and a faster ipm produce the cooling chip load needed to stop bit burning. But since you're getting smoke on part of the sheet but not on other parts it may be you're doing everything right and just have some defective material which could be hard to determine even if you have several sheets since they were probably all made in one batch.

[donchapman]

A few minutes after writing that I've never heard of HDO, my brain reminded me that I had heard of it as the grade of overlaid plywood required by the Texas DOT for their highway signs. Here's the link to Olympic Panel Products website which discusses their product Olympic Highway HDO:http://www.olypanel.com/sign_making/highway_hdo.php

[donchapman]

And here's the link to Olympic's concrete forming grade of HDO:http://www.olypanel.com/concrete_forming/index.php

I'll bet it is all the extra resins/glues in the HDO that is causing your bits and material to burn, Frank.

[fleinbach]

Yes Don this is the material used to make nearly every interstate signs we all see. And the place who is using it that I was trying to help out does concrete mold casting. For th etime being they have a few rush jobs so they settled for using birch plywood and coating it for now. Maybe when the rush is over they will get back to tryinfg to cut the HDO again.