1.675" thick douglas fir

[Kyle Stapleton]

Will be cutting out 5 and 8" tall letter out of Doug fir.
Anyone have tips in regard to to bits, feeds and speeds.
Customer would like it cut with a 1/4" bit.

Thanks

[gc3]

stuff like this i use 6mm lhf bit 4600mm/min xy 2300mm/min z

[Kyle Stapleton]

What is an lhf bit? And any recommendation on RPM's?

Thanks,

[gc3]

left hand flute i run 13k rpm on most solid woods

[Kyle Stapleton]

Why does your router spin backwards?

[gc3]

you kidding right??? you a teacher right?? you know google right??

LH spiral holds material down and forces chips downward helps to keep parts from moving... LH Spiral RH Cutting Flutes

[Ger21]

LH spiral is not a common term for router bits.
Downcut is what they are commonly known as.

You can buy left hand spiral bits, for routers spinning "backwards".

[Kyle Stapleton]

"You are kidding right?" No, I was not kidding.
"You are a teacher right?" Yes, I'm a teacher.
"You know how to use google right? Yes, I do. http://www.amanatool.com/45454-cnc-carbide-tipped-straight-plunge-high-production-3-4-dia-x-2-inch-x-3-4-shank-l-h.html


I know it may be hard to understand but teacher need the learn things too.

[gc3]

"You are kidding right?" No, I was not kidding.
"You are a teacher right?" Yes, I'm a teacher.
"You know how to use google right? Yes, I do. http://www.amanatool.com/45454-cnc-carbide-tipped-straight-plunge-high-production-3-4-dia-x-2-inch-x-3-4-shank-l-h.html


I know it may be hard to understand but teacher need the learn things too.


LH spiral is not a common term for router bits.
Downcut is what they are commonly known as.



http://www.discount-tools.com/endmills/3910.cfm
http://www.discount-tools.com/endmills/3915.cfm

[Kyle Stapleton]

left hand flute i run 13k rpm on most solid woods

I can find the term left hand spiral.

Please show left hand flute on the web, I can't seem to find it.

Also, can not find a 1/4" bit that cuts 1.75".

[garyb]

the common terminology is upcut and downcut
L or LH is coding for left hand rotation.
the discount tools label of left hand is misleading they could say left hand helix which is a downcut.
In actual fact you can purchase left hand rotation with both up and downcut tools. eg52-310L (upcut with left hand rotation) and 57-310L (downcut with left hand rotation)

Also, can not find a 1/4" bit that cuts 1.75"you can go to a foam cutter for the long length 52-564 1/4 dia 2.25" LOC, 4" OAL
they have a 25° helix but will get you by.
Gary

[Burkhardt]

....Also, can not find a 1/4" bit that cuts 1.75".

3" length and 1.5" flute are not so unusual and may do the job for you if you don't insist on cutting 1.75" deep in one pass.

You can even get 6" long bits with 3" flute like this, not very expensive:
http://www.the-carbide-end-mill-store.com/m5/770-2256--1-4-square-end-mill-extra-extra-long-htc-770-2256-2-fl-gp-30-uncoated.html
But a 1/4" bit at 6" length will be a bit chattery and require very light cuts.

[gc3]

again http://www.discount-tools.com/endmills/3910.cfm

6mm bit does not need to cut full depth...depth per pass with proper length tool

as shown

[gc3]

the common terminology is upcut and downcut
L or LH is coding for left hand rotation.
the discount tools label of left hand is misleading they could say left hand helix which is a downcut.
In actual fact you can purchase left hand rotation with both up and downcut tools. eg52-310L (upcut with left hand rotation) and 57-310L (downcut with left hand rotation)
you can go to a foam cutter for the long length 52-564 1/4 dia 2.25" LOC, 4" OAL
they have a 25° helix but will get you by.
Gary

disagree Gary...if you know tooling have experience with tooling it's very easy to decipher...there is a big market for cnc router end mills...very lucrative market all based on sale/terminology to the hobby guys, hobby market...IMHO

[Kyle Stapleton]

Thanks for the help.

[garyb]

disagree Gary...if you know tooling have experience with tooling it's very easy to decipherThats the whole point Gene if industry standards are followed then its straight forward you don't have to decipher, you can see the confusion that arose in this thread alone.
Being a trained Onsrud distributor with our own tool line for 13 years has taught us the necessity for industry standards, we deal and support tooling with hobbyist to professionals on a daily basis including aerospace companies, correct terminology becomes very critical even to new people entering the CNC industry.
Gary

[Chuck Keysor]

Kyle, for what it is worth, I once cut up a lot of OLD Douglas fir, I had salvaged. It was the most splintery wood I have ever cut. In climb mode it cut very rough, and in conventional (if I recall which was which), it splintered so much, it was like I had created a pile of toothpicks.

Good luck, Chuck!

[Ger21]

Thats the whole point Gene if industry standards are followed then its straight forward you don't have to decipher, you can see the confusion that arose in this thread alone.
Being a trained Onsrud distributor with our own tool line for 13 years has taught us the necessity for industry standards, we deal and support tooling with hobbyist to professionals on a daily basis including aerospace companies, correct terminology becomes very critical even to new people entering the CNC industry.
Gary


I'm with Gary here. I've been programming and running industrial "big iron" machines for almost 20 years. I've purchased tooling from many of the major manufacturers, and have a stack of catalogs from them. None of them ever use the terms "left hand helix". All are known as "down cut" spirals.

I believe that "left hand helix" is common with metal working endmills, but it's never used by companies who specialize in router bits.
Discount-tools.com primarily sells metalworking tooling, and uses metalworking terminology.

[waterwheelman]

Chuck, I have had the same problem with Doug Fir and I'm from the NW were it grows. It turns out that the lumber industry does not distinguish between Doug Fir and Western Hemlock. In the lumber yards it may be labeled as Hem-Fir. There is no such a tree species as hem-fir. Hemlock is a very stringy and splintery wood. I consider it the trash wood of the lumber yard. You can always tell Hemlock from Doug Fir, because it will usually be warped or soon warp after you use it. Doug Fir is a harder wood with more of a reddish color, and Western Hemlock is paler in color. Clear vertical grain (CVG) kiln dried Doug Fir makes an excellent wood for finish work.

[copcab]

I would like to clear up some misconceptions here. I am an old timber faller and log scaler. Yes, the timber industry does differentiate and sort Douglas fir from Hemlock. Hem-Fir does not include Douglas Fir. Hem-Fir is Hemlock along with 5 other true Firs. Douglas fir is not a true fir (scientific name - Pseudotsuga menziesii). Hemlock makes very nice finish lumber and is good for trim. I also prefer VG Fir however. Some of the species included in a Hem-Fir sort are not as nice as Hemlock.

[waterwheelman]

Patrick, I agree with you that Douglas Fir is not a true fir. It turns out that David Douglas who explored the Pacific Northwest and named a lot of the new plants that he found, was not as good a botanist as he could have been. That is why the scientific name for Douglas Fir indicates that it is a false fir.

Thanks for the information about Hem-Fir and it's origin. What ever Hem-Fir is it is a poor substitute for Douglas Fir. Contractors will often specify on their order sheet from the supplier that they only want Douglas Fir and not Hemlock. That's because of the poor quality of Hemlock as a wood for construction.