If you are using the correct blade for what you are doing I would be sending it back for an upgrade to the new model..

I am amazed that festool are still selling this piece of crap in Europe

they should really be staring at a class action lawsuit

Urgh! Well, since I ruined the board I had for this I might try the /4 K blade on it... Hope it works...

Last week i cut out a half circle 60cm in diameter out of a 46mm thick beech worktop, out of precaution i did some tests by setting a smaller diameter first.
I tried all the festool blades ( i got a set of 5 different blade types with mine) and all would go totally out of square after 5-10cm, then out of desperation i put on a Bosch bi-metal (not even meant to cut wood) blade, and it cut perfectly square for about half the cut and then the circle jig started bending and the cut got out of square. I was able to get the cut square with a router.

I don't think theres anything wrong with your Carvex 400, that's just how terrible they are.

Sounds like its time for some parfdog's or a real router circle jig like Jasper Model 400 which I've used with success in the past. Peter did a cool video on his idea and with those he described how to cut circles too.

Suggest cutting slightly oversized with the Jigsaw. Then fine tune the workpiece using a router with the trammel unit and appropriate cutter. This should yield acceptable results. It may be hoping for too much to have a jig saw cut out a "PERFECT CIRCLE" whereas with a router and trammel unit or even jigging up on a router table seems to be more realistic.

But you're cutting anti-clockwise! Can 't see why that should make a big difference. I'd forget the trammel,cut as near as by eye and finish with a router.

It depends on which hemisphere that the saw is being used in. In the northern hemisphere the circle needs to be cut in an anti clockwise direction whilst in the southern hemisphere the circle should be cut in a clockwise direction. This can be explained due to the Coriolis effect.This is due to the gravitation force that acts on moving objects in relation the rotational vectors of the Earth's movement through space. This was proven in history when Coriolis instructed the French Army Artillery units to compensate their aiming coordinates to more accurately land the projectiles on enemy targets. Until his advise was followed many rounds of ordinance were not as lethal as was desired by the commanders. Turns out that over the long distance that the projectile had to traverse the Earth actually had time to rotate away from the calculated coordinates of the Artillery Officers. Thus the ordinance did not land in the proper target area. I am not certain if this really has a bearing on cutting circles with a jig saw accurately or not, but how often does one get to discuss this gentleman's contribution to science?

The Mafell blade sounds brilliant - does it by any chance fit the Carvex? It might be the solution to the problem.

Peter

I've had the same problem I spoke to festool and they are going repair it il let you know how I get on

Edit: the successful spiral cutting was done with my old (and subsequently sold) Makita jigsaw. Some times I'm too quick for my own good :-(

Hi Reiska

I sometimes use the circle point thing that came with my bandsaw to do circles but I know that you do not have a bandsaw. I have attached a picture of the top of a cyclone dropbox which I made for my Cyclone Central 100mm cyclone. I made it using my OF2200 as follows...

I made my own trammel base out of a scrap of 10mm MDF. I used a centre pin of 6mm brass dowel as my pivot. I started by drilling the 6mm hole in the centre. I then made the grove on the underside where the lid fits to the dustbin (dropbox). Using the same 10mm cutter I made two deep channels marking the inner hole and the outer circle. I then used my drill with a 10mm forstner bit to make a through hole in the inner and outer channels. I then disassembled my trammel and put the OF2200 back to normal. I then used a ball bearing rounding over bit to complete the cuts at the centre and on the outside. If you did not want to use a rounding over bit you could choose any shape. If you have no ball bearing cutters then keep the trammel assembled and cut the outer circle all the way. Use a couple of thin nails or double sided tape to hold the top pieces in place and use the trammel to cut through the inner circle.

Peter

i would expect a lot better results from  a jigsaw than that. i havnt got a trammel for my trion but i would imagine it would do better. i can freehand  it good enough. i have got cuts that only needed a rub of sandpaper for them to be perfect. a jig saw  that is aimed at profetional woodworkers etc and is petraiyed to be really acurate  doing circles etcshould be able to cut a fairly large circle like the one reiska is doing. if it was a 2,3 inch circle maybe

So slightly off topic: if you had to cut a perfect circle you would rather use a router attached somehow at the end of an MFS profile?

What I was doing was a sink cover for my parents new campervan and the idea was to make it a tight fit so that it wouldn't rattle during transit.

I would but not necessarily at the end. This is the common set up for arcs...




This is the bottom showing where to put the pivot.




If you pick this one to blow it up and look closely at then inner part, there are marks and a "0" (zero). The zero shows how far the center of the bit is from the pivot axis. It is offset because the pivot axis isn't at zero on the profile's scale. If you want the inside of the bit for saving the circular piece, you go off zero the radius of the bit toward the pivot. If you want the outside of the bit for making a hole like a sink cutout, you move the radius of the bit away from the zero away from the pivot. Each tick mark away from zero is 1mm.




There are other ways to set up but this is really easy.


Tom


EDIT:
Some double stick tape is almost required because the middle will move at the end of the cut and you'll get a little protuberance that wasn't cut.

I wouldn't buy the MFS just to make a circle but if you have it, it's simple and accurate.


Tom