Router Bit Question

[markcr]

I'm pretty new to routers but I'm getting my tooling set up and am going to use the router method to cut uniform ribs. I've attached links to two different bits. One is 1/2" diameter and the other 1/4". Would one be more beneficial than the other or does it really matter? Also, the 1/4 inch bit comes in "up cut" or "down cut". Is there a benefit to either up or down cut? Thanks!

http://www.homedepot.com/p/Diablo-1-2-in-x-1-in-Carbide-Flush-Trimming-Router-Bit-DR42104/100660716

http://www.amazon.com/Whiteside-Router-Bits-RFT2100-Diameter/dp/B000HPYOJ6

[Chewie]

http://bearhawkforums.com/forum/tool...odies-business

I've used 1/4 and 1/2 both. I find the 1/4 is useful for inside cuts like holes and inside curves, but for long outside straightaways the 1/2 laminate was butter.

[sjt]

For most of the work I used:
Whiteside Router Bits RFT5125 1/2-Inch Diameter Spiral Flush Trim Up Cut with 1-1/4-Inch Cutting Length

If your intention is to mount it upside down in a router table it has the following advantages:
1) It pulls the work down on the table during the feed.
2) The 1/2 inch is slightly easier to control. Router bits yank the work uncontrollably when you take a bite that is greater then the radius of the bit. The uncontrollable nature stops if you can get the bearing against the edge. The practical difference is that it is easier to rough trim your work to 1/4 inch for use with the 1/2 inch bit.
3) Hot chips go everywhere. The upcut will move some of the chip up into the router where presumably a vacuum will pull them away. There will still be chips everywhere in the area.

It has the following disadvantages:
1) You need a router that can lock the bit in very tightly. We are completely dependent on the bearing against are template. The up cut will try to pull itself free -and out- of the router.
The down cut will force the bit against the bottom of the socket and hold firm.
2) Chips are pulled into the router and will eventually short out the brushes in the router. You must make an effort to cover some of the air passages, and you must use a vacuum.


That all said, I think it does not matter. What matters is protecting your router against metal chips being ingested. I used an up cut spiral bit and an upward mounted router that had a vacuum attached. I fabricated a plexiglass shield that blocked the chips from falling into router. I then used tape to seal most of the air passages. This would be a problem if you had to run the router for very long since it would overheat. The advantage of cutting out blanks with a router is that it is very fast and heat is not a problem.


I eventually also got a:
Whiteside Router Bits RFT2100 1/4-Inch Diameter Spiral Flush Trim Up Cut
I only used it on the aileron and flap ribs that needed a 1/4 bit.

I also purchased an assortment of bearings:
Whiteside Router Bits BB501 5 Piece Bearing


One last thing, I found that a hand saber (jig) saw was more useful then a bandsaw for rough cutting out mdf.

[Bcone1381]

I had the same questions, and you'll see my findings in this post. I am now very opinionated about the 1/4" up-cut bit. If you want a 1/2" whiteside down cut bit, I will sell you mine.

http://bearhawkforums.com/forum/tools-technics-and-best-practices/4677-router-bit-recommendation-this-thing-eats-aluminum-like-nobodies-business

[markcr]

Thanks for all the quick and excellent feedback! What a great group of builders. I was able to get my wing rib template made today. One small step forward. :-)

[BTAZ]

I used a plain old two flute 1/2" from Home Depot.

The keys were(using a router table):

No more the .062" total stackup(I.E. two to three rib blanks at a time)

Firm control when feeding into the router at the start. Once the stack was against the bearing, only light guiding pressure. If pushed against the bearing, it would fail in short order. After killing a couple, I bough a router bit set at HF and used the bearings from them.

I was never a woodworker(construction, sure, but not furniture grade) and really didn't have any router experience going into this. After learning those two lessons, everything went pretty well.

You will need to polish/debur the routed edges. I just used a file and then a Scotchbrite wheel.

Do the work where cleanup will be easy as you will have aluminum snow everywhere

[markcr]

Thanks, BTAZ. I'm a fan! I've been looking through your Wings.pdf file. It's an excellent resource. As far as router experience, I'm in the same boat as when you started. I'm comfortable with a lot of shop tools and construction in general but have never used a router.