Here, for any body interested is a comparison of two routers, one a 20 year old Hitachi M12V and a brand new Festool OF1400.

Before I start comparing the two, I will write up a wish list of what I would consider appropriate for a router for jig work.

Critical
The Base is broad enough to give ample support across the jig.
The Base is on the same plane right across to and including the surrounds of the guide bush.
The Collet is concentric to the base/guidebush.
The Base has at least one straight edge so that the router can be kept steady whilst sliding against the fence.
The Plunge is easy to use (not too hard, and smooth in its use)

Nice
The Plunge lock that can be locked without taking ones hands off the handles.
Soft start and variable speed.
Has a lock on the shaft for one spanner bit removal.
Preferably light and low centre of gravity

I have had the Hitachi for about 20 years, but with age it has developed a small amount of wear on the plunge such that when in the plunged position the bit is a bees dick off center.

I thus looked to buy what I hoped to be a vast improvement on all of the above critical features and opted for a Festool OF1400, specifically for use with a Leigh D4R Jig, I have discovered all is not as it seems.

I have the adaptor plate (Festool 463566) to mount the Carbatec RM 9 guides. (similar to the Porter Cable bushes)

Firstly the cutter shaft on the Festool is not concentric to the base system. It is about 0.15mm off centre, ie the cutter is 0.3mm closer to one side than the other. It just misses the inside of the 5/8 guide bush. I reinserted the Festool adapter plate @ 180 degrees and no difference. I did the same for the centre screwed mounting plate (permanent part of the base plate) and no difference. It is not the guide bush as it can be rotated with out altering the lack of concentricity. Presumably it is the way it is. Given the price and glowing opinions expressed about the Festool stuff, I would have taken it as a given that it would be concentric. I wonder what other people have found?

The Hitachi after 20 years is about the same out when plunged because of wear on the plunge guides.

The Festool Base has two straight edges. A short one that faces the operator if one wants the trigger with the right hand and be able to see and get at the depth settings. This short one runs against the fence for mortises on the Leigh D4R jig. Because it is so short (55mm) it is difficult to keep the Router from rotating off the fence as you slide the route along to do the mortices. Because the router has two straight edges, the longer one is on the opposite side to the fence and the base width under this edge is 10mm, making it less stable than if it had a full circle. You can turn the router around to the long edge against the fence, but then you are operating wrong handed and with the depth setting away from you.

The base is of a lesser diam than the Hitachi and also has a larger cut out in the centre, thus a narrower annulus for support on the jig and thus less fingers to support it. Visibility to the jig through the base is better on the Hitachi. With the Festool I am inclined to peer down under the jig to check clearances and finger location.

Also with the Base, I had assumed that the Festool adaptor plate (463566) when inserted would be at the same level as the base plate, to form a larger bearing surface. It isnt. It was on my old M12V Hitachi, so that you have a bearing surface the full diam of the base and right across the centre.

There is in fact 0.4mm clearance between the base plate and the Festool adapter. When the Guide bush is inserted the clearance between the guide bush "base" and the base plate is 0.63mm. So when you are doing the tenons and the tenon spacing is more than about 40mm (the width of the anulus formed by the base plate of the router is about 35mm), the router is inclined to drop (by about 0.6mm) until the guide bush "base" rests on the finger of the jig. It makes nice little dents on the edge of the tenons.

To sort it I had to pack the guide bush up 0.6mm, (thickness of an ice cream container lid) so that is in the same plane as the base. I have yet to determine if the RM9 Carbatec guide bush here is at fault. (more about that later).

The Festool has the LHS knob as a plunge lock also. It might seem like a good idea, but I think not. When using it on the Leigh jig doing the Tenons, because of the smaller size of the base, you need to slightly twist on the handle to keep a very slight (away from you) moment on the router. Trouble is, this is inclined to release the lock. Picking the router up with one hand is also likely to cause the same result.

The Hitachi has two solid handles with the plunge lock capable of being operated by your left hand pointer finger whilst still holding the router firmly. Hands don’t leave the machine and the knobs never undo, and I can pick it up with one hand with out fear of any thing undoing.

The "plunge feel" on both routers is on par, although a little less depth on the Hitachi
However, I do like the quick stop of the spinning shaft on the Festool though!
As you would imagine I am a little disappointed. For the money it should have been the ants pants. (Trouble is I don’t like the new colours of the Hitachi!)

Getting back to the Carbatec RM 9 Bushes. After two days of trying to get good joints out of the Festool, (the tenons were all too short (in width not height) for the respective mortises), I found the problem.

I had been using my trusty Hitachi, prior to my Festool purchase, and the mortises were passable. When I swapped over to the Festool, I could not get the tenons to fit nicely in the mortices. I fiddled for two days resetting and rechecking all that I could. Nothing I did made any difference. After a long sit down and think I then realised that the only thing that could leave the tenons too narrow was that the guidebush must be under size. The RM9 set, of which I was using the 5/8 (0.625in) bush was in fact 0.610in. This ended up, by the way the jig works, creating a 0.015x4=0.060in gap on each tenon. I have yet to have a conversation with Carbatec about this. Have to wait til Monday, after I have a conversation with Festool.

Cheers
Donald (On the Rock)

Thread continued here