Cutting a t-molding groove without a t-slot cutter.

[Bones]

I am toying with the idea of making some design changes mid construction of my cab, if I go ahead I will be left with two pieces of MDF each around 8 inches in length that will need to have a t-slot re-cut.

I am unable to get my router into this space and use a t-slot cutter due to partial assembly of the cab.

I thought I could mark the MDF with a sharp knife a few times and then use a slot-sized diameter drill to make a line of close holes until I have something that resembles a groove. I figure it could then be tidied up with a small file, sandpaper or even a hand saw.

Any better ideas on how this could be done?

[daywane]

just with out looking at problem spot, I would just trim off the "T" and glue the molding in place.

[Bones]

Think outside the circle huh?

It is a simple solution......

[toolaa]

Cutting off the grip on the T molding is a good idea, but you might wand to consider using a dremmel tool.

[javeryh]

If the router won't get in there because there isn't enough flat surface to run on, you might consider building a jig.  This happend to me as well and to solve the problem I built up the surface that the router needed to run on and just extended the slot cutting bit a few inches.  I only had to build the jig about 2 inches tall though... it took a while to build the jig but I am very happy I did it in the end...

[giza]

Maybe using a chisel and mallet would get the slot that you need.

[Bones]

Solution found.

A biscuit cutter.

[CJK]

Good solution -- I was going to recommend a Japanese throwing star, but the biscuit cutter will probably work out better.   

-- Chris

[daywane]

those things are not cheep!!!
Maybe now they are ( have not looked at them in a few years.)

[steptoe]

if ya can get a biscuit cutter in there, why wont the router fit, ive been thinking about using a piece of stainless sheet ground to look like a router bit, should be strong enough and rip the mdf easy, make it any size you like

[Bones]

The distance between the guide bearing and router cutting blade is dictating which side I could actually use the router on. Using the router on the outward facing edge did not give the bearing a sufficient surface to guide against.

When the grove was originally done it was done from the inside facing panel and the groove was slightly off-centre to give as much guide surface for the bearing as possible.

With a biscuit cutter I could install the groove from the outward facing panel where there were no marquee brackets to get in the way and the blade was just adjusted to the correct height.

The real solution would have been to router the original groove on the outside facing panel when the T-slot was first done and then assemble. This way any touch ups could be easily done. This lesson I take with me.

[monkey puzzle]

The buiscuit cutter is a good idea but it might struggle cutting through MDF as they are designed for cutting buiscuits.

 

[markb]

As mentioned previously I have also used a dremel with a cutting blade for routing T-mold slots. It's time consuming but good for those awkward places.

[Wienerdog]

A biscuit blade is too think for the T-molding, you'll probably have to cut and then glue the T-molding in.

[Bones]

A biscuit blade is too think for the T-molding, you'll probably have to cut and then glue the T-molding in.

Yeah the groove from the biscuit cutter is wider and on it's own it wouldn't hold but it will help locate the T and I feel comfortable to glue it from here.

I was going to use silicone rubber (Silastic), there ain't much that stuff won't hold together.