Carvex 420 cannot cut straight - Problem Solved

[jeh]

Cuts start straight but then the blade starts to bend like a banana. Always to the right and in the process burns the center of the blade. When removed the blade is straight (no permanent bend). Material was 5/4" pine. I had not used it for anything other than thin plywood up until the 5/4 pine. It may have been doing it before, but it was not noticeable in 1/4" plywood.

I will say that after I made the first cut which was a straight line cut I noticed the cut was not quite perpendicular. I switched blades and it got worse with the next cut. Any ideas?

 

[Administrator_JSVN]

Which blade are using?

Did you set the carbide jaws to the blade?

Are you pushing the cut or letting the saw do the job?

 

[Staniam]

Can you describe how you have the Carvex set up? On guide rail, which base, power/speed setting and which pendulum setting?

Recommendations:

Triple checking you're using the right blade for the cut
Set speed to "A"
Set Pedulum to "3"
Don't force the Carvex forward, its powerful so it should go by itself with minimal forward force
Adjust the blade "teeth" to the blade. Tighten all the way then loosen about a quarter turn

 

[jeh]

Can you describe how you have the Carvex set up? On guide rail, which base, power/speed setting and which pendulum setting?

Recommendations:

Triple checking you're using the right blade for the cut
Set speed to "A"
Set Pedulum to "3"
Don't force the Carvex forward, its powerful so it should go by itself with minimal forward force
Adjust the blade "teeth" to the blade. Tighten all the way then loosen about a quarter turn

I was on rail with the pendulum set to 3 using a FSG 75/4 blade.

The problem has resolved itself. It looks like a some point a small piece of the splinter guard came off and wedged itself between the blade guide giving it zero support. I took the plastic piece out and tightening the blade guide down just enough for it to be slightly loose. I'm back in the game.

Thanks for the quick responses.

 

[Administrator_JSVN]

For the benefits of others, and you [member=652]JimH2[/member], we do not recommend using the jigsaws on the guide rail with materials thicker than 18mm (3/4").

Shane

 

[ear3]

Just curious as to the mechanics behind this recommendation?

For the benefits of others, and you [member=652]JimH2[/member], we do not recommend using the jigsaws on the guide rail with materials thicker than 18mm (3/4").

Shane

 

[Administrator_JSVN]

Materials any thicker and the jigsaw is fighting the guide rail essentially. Of course, the type of material can change that but it's a general rule of thumb.

 

[ear3]

Materials any thicker and the jigsaw is fighting the guide rail essentially. Of course, the type of material can change that but it's a general rule of thumb.

Got it.  Thanks.

 

[wow]

Materials any thicker and the jigsaw is fighting the guide rail essentially. Of course, the type of material can change that but it's a general rule of thumb.

OK, I must be stupid today. Why would the thickness of the material have an effect on whether or not the saw fights the rail? The rail only adds - what - 5mm in height? Assuming the cut is at 90 degrees, the thickness of the material wouldn't seem to me to be a factor. Or to put it another way, wouldn't the thickness then be a problem with or without the rail?

Tell me what I am missing?

 

[Administrator_JSVN]

With the rail, you're basically forcing the jigsaw and blade down a specific path. Due to the grain and other factors, the blade will have a natural path it wants to follow. These small deviations are normally unnoticeable and not a factor when cutting by hand. But are multiplied when on the rail. The greater the thickness of the material, the more it will want to try to follow this natural path and deviate from the course of the guide rail. They are fighting against one another.

 

[wow]

With the rail, you're basically forcing the jigsaw and blade down a specific path. Due to the grain and other factors, the blade will have a natural path it wants to follow. These small deviations are normally unnoticeable and not a factor when cutting by hand. But are multiplied when on the rail. The greater the thickness of the material, the more it will want to try to follow this natural path and deviate from the course of the guide rail. They are fighting against one another.

OK - so you naturally/unconsciously correct for the grain and other variances when cutting by hand, which you can't do when the saw is on the rail. Got it!

Thanks for the explanation.

 

[windmill man]

How does forcing a jigsaw down a rail differ from forcing it down a straight line , you have marked  [unsure]

 

[Administrator_JSVN]

How does forcing a jigsaw down a rail differ from forcing it down a straight line , you have marked  [unsure]

Binding.

Maybe I'm not doing a good job of explaining it. Our recommendation is a maximum of 3/4" using the guide rail adapter for the jigsaws. If you choose to use it on thicker materials, you may not get the best results.

 

[windmill man]

Mmmmmm interesting

Thanks Shane

 

[Administrator_JSVN]

From the Trion manual, for instance...

The use of the Festool guide system FS facilitates
the production of straight and precise cuts, particularly
with material thicknesses up to 20 mm
(1/4").

Apparently they aren't good at metric to imperial conversion, since that would be closer to 3/4".

 

[jmbfestool]

Carvex body and blade are pretty parallel to each other, allowing you to use a guide rail.
  You will find many other brands this isn't possible.

You will find if you was going free hand with other branded jigsaws after couple inches into work piece the jigsaw body will be "drifting" going sideways yet you are cutting "straight" forward.  You naturally turn the body of the jigsaw as you are fallowing the line to stay on track.  Now if you had a fence to run along you wouldn't be able to turn the jigsaw body so instead the blade will start to bend outwards/inwards. Cutting Thinner material blade will cope but thicker materials it won't.  Even the carvex isn't perfect and has its limits and although it might appear perfectly parallel it won't be and thicker material will show this. 

Another point with free hand. While you are turning left right left right slightly as you are trying to stay straight and fallow the line you take the strain out of the blade because you are breaking the natural path the blade is trying to fallow.

other factors which cause problems when Guide railing it is blade wear. If one side of the blade has started to wear out slightly then the blade will try and drift, in thinner material this won't be noticeable but thicker material its exaggerated so it tries the wander.  Free hand this wouldn't be as noticeable or a problem because you would turn the jigsaw body as soon as you notice the blade not going the direction you dont want it to.

Also type of wood and the grain of the wood again free hand with the slight turns tweaking its direction as you are cutting breaks the the path the blade wants to try and fallow. 

 

[glass1]

My Trion like all jig saws I have owned before deflects very easily. I find anything beyond a short cut to be unreliable. No matter the material. Obviously the thicker and harder the more challenging. I have yet to try the Mafell. I feel most of us have unreasonable or hopes for the jig saws abilities. 

 

[Administrator_JSVN]

[member=5671]jmbfestool[/member], that might be the most eloquent thing you've ever said! [tongue] very well said.

[member=4687]glass1[/member], you should be able to easily achieve cuts without the deflection with your jigsaw. Are you setting the carbide jaws correctly? Which blade are you using?

 

[glass1]

I do like my trion except the sight line is not good with the front plastic shroud on. I leave it off. I just feel people have unreasonable exceptatations of jig saws especially with festool. I probably am not as diligent as I should be with the carbide blocks. I am building a large custom stair now and doing quite a few scribe cuts on large glue up stair treads that die into a stone chimney.  I will get some festool blades in the am. I am cutting 3/4" mahogany what blade(s) do you recommend. Thx

 

[Administrator_JSVN]

The FSG blade is best for perpendicular cuts.

http://www.festoolusa.com/search/?q=Fsg

Let the jigsaw do the work.