Carvex PSC400 not guiding the blade thru curves

[fritter63]

I'm wondering if you guys are being a bit unrealistic in your expectations? Despite what Festool may claim.... as a woodworker (and NOT a finish carpenter!) I've NEVER considered any jigsaw to be a precision cutting tool.

Cutting a sink hole in a counter is different than getting a perfect circle.

Even when cutting circles (on a pivot point) on my bandsaw I run into issues with blade wander.

 

[Stone Message]

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

 

[RC]

Well Fritters, that's quite exactly what I've always used my ex. Makita jigsaw for - to cut round circular final cuts. I use my TS55 or hand saws for straight cutting and my Multimaster for plunges into ackward places.

The reason I swapped my Makita for the Carvex was precicely the promise of repeatable precise circles with the core cutter jig and better angle control with the angle base. An added expectation was to be able to use the Carvex as a light scrollsaw in the CMS insert, which doesn't work either because the blades wonder away from the 'automatic blade guide' forward even when pushing the work piece against the saw.

I've now experienced the blade wondering and twisting/deflection both hand held and inverted in the CMS on both curved cuts and straight cuts with the blade wondering off to the right.

Funnily enough the el cheapo Craftomat blades are about the only ones that actually touch the guide and the Festool blades are barely touching the V-guide even when stationary.

Could the box of Festool blades I have be defective? (Not that I can tell any malformation by eye atleast)

 

[Alan m]

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

 

[tbellemare]

I just showed a customer this morning how to cut 13" circles out of 3/4" plywood using a 1/2" downcut spiral bit, OF 1400, and MFS 400. We did a test piece before we tried the setup on his customer's wood. I was off by about a millimeter. I left my glasses at home...

We adjusted the MFS and then made a real one. It came out just right.

Tom

 

[RC]

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.

 

[galwaydude18@gmail.com]

A router is the only to do this. I know festool have designed their jigsaws to cut circles and I have the trion 300 but I wouldn't consider it for cutting circles. I would do it with my router. The bit is at 90 degrees and you won't creep like a jigsaw does.

 

[tbellemare]

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

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

[attachthumb=#1]

This is the bottom showing where to put the pivot.

[attachthumb=#2]

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.

[attachthumb=#3]

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.

 

[jmbfestool]

I use a jigsaw to make circles quickly for rough work but if you want a perfect circle the router is the ONLY way to go or CNC off course.

You don't have to use the MFS it's an expensive way to make circles especially big circles I have the MFS but never use if for circles any way.

I find for one off circles a piece of 12-18mm ply wood fix it to your base and fix it to your centre point job done perfect circle easy.

Jmb

 

[tbellemare]

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

Tom

 

[Stone Message]

For larger circles the Parf Dog as a trammel point is the answer - it is tough and does not move under pressure.

Peter

 

[RC]

Update:

Tried the S 75/4 FSG blade on a slightly smaller circle (37cm) on the same piece of board with a lot better results. This blade actually cut mainly square (it's about 1.5x the thickness of the S 75/2.5) and kept with the curve fairly well. My only gripe with this blade is that the cut quality isn't anywhere near "finish ready" with lots of splintering going on so once I get a replacement board I guess I'll have to use this setup for a rough cut at about 39cm and then rig my router to come in for the last 10mm and hope that it'll be enough safety zone to avoid splinters. Or should I try to tape the edge with blue tape just in case?

I guess it's off to the plywood store to get some router base jig material and figure out how I can attach a jig like this trammel thing onto my OF1400 base... And check that I have a long enough straight router bit to trim the 28mm edge in one pass (not totally sure about that even thou I do have multiple straight bit otherwise).

On a related note:

What's the point of the other gazillion Festool blades since they are too thin to stay square when in the Carvex so why isn't there a fine finish blade which is meant for cutting tight curves and be thick enough to stay square through the piece at the same time? Has anyone dared to try if the Mafell Cunex blade would fit somehow into the Carvex blade holder?  [tongue]

If I read the Festool blade guide pictograms correctly then only the three different lenght S75/105/145/4 FSG blades and the S75/4 FS are for cutting squarely and only the FSG blades and the S 50/1.4 K are meant for cutting tight curves? I can understand the different blade geometries are meant for different materials like metal or plastic, but if the blades wonder to random angles sideways while cutting they are worthless in my opinion. What does the black icon mean in the S 50/1.4 K blade 'specialities' column?

 

[Stone Message]

Reiska

If you are going to finish off with the router you need to plan how you will guide it around the circle - forgive me if I am teaching you to suck eggs.

Peter

 

[Kev]

Update:

Tried the S 75/4 FSG blade on a slightly smaller circle (37cm) on the same piece of board with a lot better results. This blade actually cut mainly square (it's about 1.5x the thickness of the S 75/2.5) and kept with the curve fairly well. My only gripe with this blade is that the cut quality isn't anywhere near "finish ready" with lots of splintering going on so once I get a replacement board I guess I'll have to use this setup for a rough cut at about 39cm and then rig my router to come in for the last 10mm and hope that it'll be enough safety zone to avoid splinters. Or should I try to tape the edge with blue tape just in case?

I guess it's off to the plywood store to get some router base jig material and figure out how I can attach a jig like this trammel thing onto my OF1400 base... And check that I have a long enough straight router bit to trim the 28mm edge in one pass (not totally sure about that even thou I do have multiple straight bit otherwise).

On a related note:

What's the point of the other gazillion Festool blades since they are too thin to stay square when in the Carvex so why isn't there a fine finish blade which is meant for cutting tight curves and be thick enough to stay square through the piece at the same time? Has anyone dared to try if the Mafell Cunex blade would fit somehow into the Carvex blade holder?  [tongue]

If I read the Festool blade guide pictograms correctly then only the three different lenght S75/105/145/4 FSG blades and the S75/4 FS are for cutting squarely and only the FSG blades and the S 50/1.4 K are meant for cutting tight curves? I can understand the different blade geometries are meant for different materials like metal or plastic, but if the blades wonder to random angles sideways while cutting they are worthless in my opinion. What does the black icon mean in the S 50/1.4 K blade 'specialities' column?

Your confusion over Festool jigsaw blades is making me feel a lot less stupid!

 

[ajones]

Update:

Tried the S 75/4 FSG blade on a slightly smaller circle (37cm) on the same piece of board with a lot better results. This blade actually cut mainly square (it's about 1.5x the thickness of the S 75/2.5) and kept with the curve fairly well. My only gripe with this blade is that the cut quality isn't anywhere near "finish ready" with lots of splintering going on so once I get a replacement board I guess I'll have to use this setup for a rough cut at about 39cm and then rig my router to come in for the last 10mm and hope that it'll be enough safety zone to avoid splinters. Or should I try to tape the edge with blue tape just in case?

I guess it's off to the plywood store to get some router base jig material and figure out how I can attach a jig like this trammel thing onto my OF1400 base... And check that I have a long enough straight router bit to trim the 28mm edge in one pass (not totally sure about that even thou I do have multiple straight bit otherwise).

On a related note:

What's the point of the other gazillion Festool blades since they are too thin to stay square when in the Carvex so why isn't there a fine finish blade which is meant for cutting tight curves and be thick enough to stay square through the piece at the same time? Has anyone dared to try if the Mafell Cunex blade would fit somehow into the Carvex blade holder?  [tongue]

If I read the Festool blade guide pictograms correctly then only the three different lenght S75/105/145/4 FSG blades and the S75/4 FS are for cutting squarely and only the FSG blades and the S 50/1.4 K are meant for cutting tight curves? I can understand the different blade geometries are meant for different materials like metal or plastic, but if the blades wonder to random angles sideways while cutting they are worthless in my opinion. What does the black icon mean in the S 50/1.4 K blade 'specialities' column?

Your confusion over Festool jigsaw blades is making me feel a lot less stupid!

I looked at my cunex blades this morning and it has extra thickness where it fits to the machine I guess it has been engineered this way as to not fit other brands I only have the p1cc so I cant actually try for fit in anything else

 

[RC]

If you are going to finish off with the router you need to plan how you will guide it around the circle - forgive me if I am teaching you to suck eggs.

No offence taken Peter, I haven't done this with a router before so I'm all ears for suggestions  [smile]

Reading your previous post I envisioned a strip of thin ply that has centered 5mm holes at suitable distances that are happenstance the same size as the Core jig pin  [tongue] and the other end would be the shape of the OF1400 bottom and holes to attach it to the router as a "base plate". Just haven't been able to look at the routers base plate to see how it is screwed/attached to the router. I'm expecting to then be able to run the full circle with the router effectively at the 'end of a rod' so to speak.

I'm mostly unsure how to keep the piece in place since can't really clamp it from the sides with the clamping element nor putting a clamp in the middle is going to work much better since I'm routing all around it. Wonder could the routing be done in multiple segments of the circumference without too bad burning/misalignment and rotate the board one segment at a time?

The only solution that I've come up with the possibility to doing continuous circle is some sort of a stand that's clamped to the table and has something similar material on it like the anti-slip rubber of the guide rails or some sort of a vacuum clamp. Unfortunately I don't have a vacuum clamping system nor the materials to build such a anti-slip stand either.

Another question about using a router for this sort of edge trimming is that should I use a straight bit or a spiral cutting bit (up or down)? Does it make a big difference in the finish quality?

 

[tbellemare]

I'm mostly unsure how to keep the piece in place since can't really clamp it from the sides with the clamping element

Double-sided tape works well.

I would also use a downcut-spiral bit and a sacrificial surface underneath as a sort of splinter guard. If you tape the sacrificial piece to the work surface and the work piece to the sacrificial piece (inside and outside of the proposed circle), you should be secure enough for the operation.

Tom

 

[Stone Message]

Reiska

Toms last post is good advice but make sure that the tape is doing the job before you find out the hard way.

As you are trying to make a hole for a round sink - might there be a lip to the edge of the sink to hide the few mm near the hole? That would give you some wiggle room.

You could use the piece of wood that you have ruined as a base piece.

Fix the new piece of wood to your base piece. At the centre (of the sink) make a hole all the way through your new piece into the base piece - that way when you come to the end of your circle the trammel is still fixed at the centre (of the base piece).

Cut the hole using your trammel taking care at the very end when the plug in your new piece is free to move if the double sided tape has failed.

You could use some thin nails through your nice piece of wood (at the edges and in the centre) into the base piece and fill the holes later.

Spiral bit is good. Do the cut in stages if your meet too much resistance.

Peter

 

[Jeff2413]

I have the same saw.  It's a joke really.  My 18v Makita cuts much better and cost $200.    My $100 cordless Dewalt cuts better.  My Bosch cuts just as well.  Only reason I haven't sold it is it's convenient switching cords between tools and I don't wanna screw the poor dude making the purchase.  It's at best a $125 saw.  And yes I own many green tools.  Just not impressed with this one. 

 

[tbellemare]

You have a Carvex?

Tom