Cutting birch

[xtreme872]

New to all this. I am gonna be cutting a bunch of letters out of 1/2" birch. What's the best bit to use to get a good finished edge

[Kyle Stapleton]

Solid wood or ply?

[xtreme872]

Sorry plywood

[Burkhardt]

How big the letters? Straight cut or chamfered/beveled? Using tabs? Dense baltic birch ply or birch veneer on softwood?

[xtreme872]

Probably Baltic burch if I can get some from a local source plan on doing straight cut. Most letters wil be at least 18" high not plan on using tabs

[genek]

What are you doing with the letters. if it is for indoor use and for personal or retail for others to use. Is it for flower arrangements etc. ??? if you are doing this or for decorations shift over to mdf.

[xtreme872]

outdoor use for a customer to sell in a shop for retail use.

[genek]

outdoor use for a customer to sell in a shop for retail use.


what do they do with the letters. on wreaths etc. if so.. would use mdf and paint it. They do not stay out long and are thrown away.

[guitarwes]

1/4" or 3/8" compression bit.

[ADAPT_Shop-Brady]

Here's the bit we use for 1/2" bb ply:
https://amzn.com/B0012K5YDK

[xtreme872]

Thanks this is all new to me.I have been in the sign business for 18 years but just bought a shop bot. They only sent me a starter set with setup and has a upcut and downcut which make frays on one side or the other obviously, ... I will order this one today.

[guitarwes]

Try centuriontools.com. They have good bits and are very competitively priced.

[Burkhardt]

Going 1/2" deep with a 1/4" bit (or worse a 3/8" bit) at an appropriate feed rate for good chip load will subject the letters to quite some machining forces and hold-down may become a problem. If you don't want to use tabs and can not use vacuum because the letters are too skinny I suspect you are planning to use double sided tape? I don't believe that will work and at least require a bit of experimentation. Using an 1/8" bit and going in 2 depth steps will create much lower forces. If you start with a downcut bit for the first step and then switch to an upcut bit for cutting through it should come out clean both sides. But at the end, using tabs and the bigger bits may be faster in spite of the clean-up.

[genek]

One of my tricks is to spray the birch with lacquer or paint then use a single flute bit. This way you can cut all the way through the material. As it cuts it packs the chip behind and that will hold the letters.

[ADAPT_Shop-Brady]

One of my tricks is to spray the birch with lacquer or paint then use a single flute bit. This way you can cut all the way through the material. As it cuts it packs the chip behind and that will hold the letters.

Gene,
What am I missing, what does the lacquer/paint do?

[genek]

Gene,
What am I missing, what does the lacquer/paint do?
helps prevent it from chipping.

[garyb]

use a mortise compression tool, it has a shorter upcut length which allows you to reduce the stepdown.
use the correct tooling and feedrates and you won't have to all this additional to get a good clean cut
Gary

[xtreme872]

Ok I ordered this bit https://amzn.com/B0012K5YDK. Been playing with some 1/2" birch. Cant get it perfect splintering on top some and leaving some rough edges on sides in some places? Any help with feed rates etc? Is it possible to get a perfect edge?

[Kyle Stapleton]

We cut it with a just a 1/4" downcut in two passes, first pass is a climb leaving a skin of .04" seconded is conventional .01" into the table.
All of this is at 4 ips 12000 rpms

[xtreme872]

I tried this and still get a few rough edges some are very clean and some get ruff. almost like it starts out great and then gets worse as it goes.. not terrible but rough in spots.2842328424

[Davo]

The one picture on the right looks like vibration of the part to me - but I'm just throwing that out there because that seemed to be what caused my issue

I've only ran into it a few times on small items

[xtreme872]

ok... I am getting there.. what i am trying to cut is the monogram circles like people paint and hang on there door would MDF better for this? Also My bit is squealing some.. I know that means something

[genek]

I make the Monogram circles and letters. I use a straight flute bit and 3/8 mdf. I prime the boards then cut. The straight flute bit does two things. one it does not put up or down on the material. two it pack the chips behind so the letters do not move as i cut them out. The bit I use comes from Lowes it is a very cheap bit..

[ADAPT_Shop-Brady]

I've been getting good consistant results cutting 1/2" (9ply) prefinished baltic birch:

Whiteside UD2102 https://www.amazon.com/Whiteside-Router-Bits-UD2102-Compression/dp/B0012K5YDK
16k spindle speed
256"/min cut
160"/min plunge

I do it in one pass and finish with a round-over bit in the router on each side and a quick wipe with 200 grit.

extreme872 - are your last photos using 1/2" BB? The second photo results could be caused by lack of sufficient hold down.
Did the first pass look as rough? May have started bouncing once the last pass removed the lateral stability.

[ADAPT_Shop-Brady]

The one picture on the right looks like vibration of the part to me - but I'm just throwing that out there because that seemed to be what caused my issue

I've only ran into it a few times on small items

I missed this response before my last post. I agree, might want to try adding tabs for support.