Makita trim router - do I use the straight guide to chamfer?

[ElectricFeet]

I've just bought a Makita trim router. I've never used one before.

I need to make some very slight chamfers on the edge of some 19mm (3/4") valchromat (a bit like the edge of the MFT's MDF, but smaller).

I will have a bearing-guided chamfer bit. Probably this Axminster one (I have yet to buy it):

[attachimg=1]

The router comes with a straight (edge) guide, which I've used on larger routers, but I've never seen anyone using them on a trim router.

View attachment 2

The manual -- yup, I'm a nerd; I read it -- says that it's to be used "when chamfering or grooving".

Grooving, I get, but chamfering? Does anyone use a straight guide for chamfering? Should I?

 

[Jiggy Joiner]

If you’re using a bearing guided cutter, the chamfer will follow the shape of the work piece.
If using a standard (non bearing guided) cutter, you will need to use a guide, or guide rail, or a jig.

 

[Michael Kellough]

Try it with and without the edge guide. You might find without the edge guide that the tiny bearing is embossing a shallow groove in the edge of the material.

If it is, set the bit depth a little deeper and set the edge guide to move the bit out the same amount to keep the bearing off the wood.

 

[ElectricFeet]

Thanks [member=69479]Jiggy Joiner[/member] and [member=297]Michael Kellough[/member]  Both posts make sense. I'll try without (as I will have a bearing) and if I have problems I'll try with.

Thanks again!

 

[Michael Kellough]

There is a risk using the edge guide. At the beginning and end of a run when only half of the guide is in contact with the work it’s possible for the router to pivot towards the work and the bit will over-cut. To avoid that requires changing how you apply pressure to the router/guide. It’s a little tricky.

It’s much easier to just use the bearing, just try not to put too much pressure on the bearing with soft material.

I suggested the guide because the material is similar to mdf. While the surface of mdf is pretty tough the center is much softer and that is where the bearing of a chamfer bit will ride.

 

[ElectricFeet]

Just as a follow up on this:

I had intended to use my Makita trim router, thinking it would be the right tool for the job (indeed I bought it specifically for this job) but in the end I gave up on it -- I couldn't get the accuracy I needed for a ~1.5mm chamfer. The machine moves waaay too easily in the base. However much I tightened it, it kept changing the depth of the chamfer. Complete waste of time and money.

In the end, I used my OF 1010 with an Axminster chamfer bit. The outrigger foot on the OF 1010 worked an absolute charm: it was fantastically well-balanced (I made sure I had a smooth flat surface underneath). And the chamfer bit was precise, with no problems at all. I ended up chamfering over 45 metres of Valchromat edges -- including going round 48 tightly-rounded corners -- without a single error.

Very pleased with the OF 1010. It continues to surprise me with the quality of work it can produce.

Now on to finishing, which is always my nightmare (I'll post on the finishing board).