Rail & Stile on router table Im baffled

[rog]

Hi guys i'm really struggling, i'm making some french doors using a freud rail and stile set, I have cut the profie on the sides of the rails which are 600mm long. I keep the same setup in the router table (cutter at the same height etc) but as I run the long stile through the cut is always off centre.

When i do another test cut on a short piece of timber its fine. I am guessing the long lengths are tipping slightly or something, i have a feather board holding down and one pushing onto the fence.

i'm starting to question the router, or the jessem routalift its mounted in.

Any Ideas?

rog

 

[Argee]

Which side is it off centre, the upper or lower part of the workpiece? If it's off towards the lower part, that would seem to suggest a dip in the table, although the feather-boarding ought to rule that out.

Ray.

 

[rog]

hi, the cutter runs off centre towards the lower side - the grove its cutting that should be centre is 1.5mm off centre towards the bottom (router table side) i have put a 6 foot level acoss the table and its perfectly flat.

The only thing i can hink is the timber is not being held down as it enters the table (like its lifting a mm or so as it passes the cutter) - or some how the load is forcing the cutter down some how.

The only thing I can think is to take the makita out of the table and try my other router! - a bit drastic but dont know what else to do.

 

[mailee]

It may sound silly but have you locked the router to height? If it is free to move on the pillars it may be moving as you cut. Just a thought.

 

[Argee]

hi, the cutter runs off centre towards the lower side - the grove its cutting that should be centre is 1.5mm off centre towards the bottom (router table side) i have put a 6 foot level acoss the table and its perfectly flat.

You don't say how wide your table is - is it possible that there's enough overhang of the piece at both the start and finish of the cut that the weight of the overhang is overcoming the featherboards? If that's a possibility, support the piece level at both ends. Can't think of anything else that would cause it if the table is flat.

Ray.

 

[Steve Maskery]

Well I think either the cutter is moving or the wood is

Is your wood perfectly straight? If it is slightly crowned (high in the middle) you would get the effect you describe, although I do admit that 1.5mm is a lot if it is being held down with a featherboard.

Cheers
Steve

 

[rog]

Thanks guys, a bit more info. i'm using a jessem routalift in their own top so I guess the table is 3 feet wide. I have roller stands each side which i have set to the same height as the table - with a 6ft spirt level.

The timber is very slightly bowed im talking if i put a 6ft level on it it rocks maybe 0.5mm over 6 ft.

The cutter is locked down, I was starting to think about play in the bearings or something being bent in the router but think this would just make a wider cut?

As i said before i was going to swap the erouter to see if that helped.. im just lost how a 2 foot piece is ok but a 8 foot piece is no good.

 

[lemonjeff]

Rog,

Is the error the same over the whole length? As opposed to just and the ends or in the middle?

 

[bob_c]

If its only bowed 0.5mm ,then it will be even less over the 36" which is the width of your table.I cant see that being the problem.Have you tried turning the wood over with the bow on the other side?

 

[Argee]

I'm assuming that the featherboard is on the infeed side? Have you tried the addition of another one on the outfeed? lemonjeff makes a good point - whole length error or partial?

Ray.

 

[rog]

Thanks for the advice, I can tell you that the fist 6 inches of the run are correct then it runs out withing about a foot, then its consistantly out along the length.. its 1.4 - 1.7mm out - asI said always thiner on the face of timber thats face down on the table.

I have scrapped the piece of white oak i ran so i can rip the moulding off on the table saw and try again. I will try it upside down this time.

cheers rog

 

[dickm]

Are you quite sure the table itself is flat? I had exactly that problem with a Bosch table that bowed down in the middle from the weight of the router. A combination of this and any bow in the timber might just cause the run-out.

 

[rog]

Thanks everyone for all your help.

I went back to the shed and had a long look at the job, on inspection the table is bowed, you can only see it if you pu a level straight through the centre and off both sides - i cant belive a jessem top would bow with the weight of my makita 3612!!!!

in the short term i jacked the bow out with two pieces of 6X2 relevel the routalift, put feather boards on the in feed and out feed and on the fence to hold it down (in and out feed).

The result ---- not too bad i got a deviation of about 0.3mm

Looks like i am going to have to rebuild the routertable with more support!

Thankyou for all your help and advice.. you've all been great.

 

[Big John]

I've got the Jessem. There should be some adjustment screws ( you can access them without removing the plate ) that should level things up. Have you tried this?

 

[OPJ]

Are you quite sure the table itself is flat? I had exactly that problem with a Bosch table that bowed down in the middle from the weight of the router. A combination of this and any bow in the timber might just cause the run-out.

That's funny. I have the Bosch RT 60 table and it seems to bow upwards (convex) in the middle, with a Freud FT2000VCE router in place! I also find that my mounting plate is convex with the router in place, even the replacement I made from a flat sheet of Tufnol has gone the same way.

It appears you have the problem sorted now Rog, but I was going to double check to see if you are running it on a very slow speed? Otherwise, you'll experience a lot of vibration, which can cause things to move... :?

 

[kafkaian]

These links might help in setting up if not already covered. Apologies if they have:

New Woodworker

And although about doors and does not cover the tenon, this might have some useful lining up tips vis-à-vis the Freud bits:

Wood Whisperer

 

[rog]

Thanks for the links guys they are great.

The Top is acually bowed, I know about the adjustment screws in the Jessem top - the routalift is flush with the top but the whole top is slightly bowed making the cutter a mm or two lower than the edges of the table - when I make a test cut on a short piece its ok. When the feather boards go on Im forcing the timber down the dip and cutting the profile off centre.

Im only running the cutters at 9000 rpm so dont have much vibration - I am using the freud cutters for exterior doors so there quite big (44mm stock) - There great but expensive! i picked them up in the USA for less than half price.

Cheers again guys.

 

[dickm]

Glad you've found the source of the problem. I sorted the Bosch table by drilling and tapping the underside of the top, and bolting a piece of fairly heavy ali angle underneath. It seemed to cure the problem, but it was still never as flat as the C/I table on the Ryobi table I bought recently