1/4" - 5/16" ROUTER BIT LONGER THAN 1"

General Discussion
1

I got a weird surfboard related project I’m working on.

It’s a long story but I really just need to cut slots into the rail of a blank that I am working on.

The slots need to be 5/16" wide by about 3" long and go all the way through the blank.

My goal is to add short stringers…

Anyway, I am looking for a router bit that’s somewhere in the neighborhood of 5/16" diameter with longer than a 1" cutting depth.

I know they have those ones that look like drillbits that they use in CNC machines for cutting foam.

But, they are expensive!

Anybody have an old one laying around?

Alternatively, would a drill bit work in a trim router if I get a router speed control and turn it WAY down?

Any other ideas?

I could use my current bit and just do a double pass…

2

If I needed to accomplish the task you are describing as a one off I would mark it out and use a simple drill jig to drill a series of connected holes.  Then I would take the blades out of my surf-form and my micro rasp and clean it up to the lines.  The drill jig could be a simple block of hardwood you’ve drilled a perfectly square hole through on a drill press.

3

Circular saw, with a drill bit and a chisel to square up the end…

4

This pre or post lam? 

And do you need to plunge the cut? Aka you are starting and stopping inside the plan shape, not exiting the rail. 

If its pre lam and you don’t need to plunge then  a slowed down bit will work (drop it down to drill speeds) Not the best but it’ll get it done. 

If you need to plunge, drill a hole at the beginning, then place your router in place (bit through hole) and make your pass. 

If it’s post lam I’d get something like this

https://www.amazon.com/Router-Cutter-Straight-Inches-Length/dp/B07Q85872K/ref=mp_s_a_1_8?keywords=3%2F8+extra+long+router+bit&qid=1566792731&s=gateway&sr=8-8

 

 

5

Why router?

It mostly foam, so a drill will do the job.

Plenty long drill bits around.

Then run a file to join the holes.

6

Thanks for all these ideas guys.

These are helping me look at it in different ways .

 

It is in the foam. Preglass.

No plunge needed.

 

 

7

what is collet size of router you will be using??

8

Test your drill bit idea in some spare foam. I think it will work. Not ideal but workable for your one off. 

All the best

9

Thanks Greg

Yeah, that’s what I was thinking…

The reason I was leaning towards using my (trim) router is because I already have a jig for routing straight lines.

So, if the drill bit works even kinda well, it should do the trick.

10

1/4" collet in a trim router.

11

Send a pm to me or surfgearhawaii@hawaii.rr.com and I have a bit for you. Will not ship until tuesday. 

aloha

12

AWESOME!

Thank you so much!