Ts 75 bent track

dangav08

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Jan 4, 2016
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I've owned my track saw for 6 months so far and loved every bit of using it so far. The other day I took it out to rip some straight edges on some 4/4 cherry lumber and when I went to put the two edges together that I was going to joint and glue, there seemed to be a slight bow on both edges. I looked at it for a few seconds confused and then looked up and down the track. Sure enough, it looked a little bent, around 2 mm down the length in the middle. Has anyone experienced this problem before? I found it very strange that this could happen. I have always made sure the track was well placed and never in a place where it could be damaged or bent in any way. Any  feedback would be great.
 
Many have trouble hooking two track together, and suggest a single track.
As it seems that you have a single track, I guess you need a straight track??
 
If your rail had been straight before, it must have become bent either while being stored or during handling. These rails are made from an alloy that allows for some degree of flex and therefor must be properly supported while being stored and handled. You may want to observe where the rail bends and try picking the rail up at the bend with the bend down such that the rail's weight will help straighten it.
 
Are you sure your rail is bent?  Some types of wood have more movement in them.  When you cut the wood you can be releasing tension in the wood, causing the wood to bow a little as your cutting it.  It would take a lot of stress to bow the rail being it's 10-12in wide aluminum.  I would take a level and put it on the rail to confirm there is a bow.
 
When I bought my TS-55 the rail that came with it was 2mm out around 23" from one end.  I discovered this when joining two rails with a  55" self made straight edge, made from 8020 2012 extrusion that connects to my rails to ensure they are straight.  I contacted Festool service on the advise from Bob Marino and they immediately sent me a replacement.
 
Surely a 2mm bow in the track would result in more than 'a slight bow on both edges' of your workpieces?
 
Corwin said:
If your rail had been straight before, it must have become bent either while being stored or during handling. These rails are made from an alloy that allows for some degree of flex and therefor must be properly supported while being stored and handled. You may want to observe where the rail bends and try picking the rail up at the bend with the bend down such that the rail's weight will help straighten it.

I am pretty sure all Al alloys have about the same modulus, so they all flex the same under the same weight.
They also should not creap under their own weight storing them. Maybe in the flat direction thay could bend easily, but not sideways.

Many skis are a alloy composite, and I have never heard of them loosing their sidecut from storage.
 
I don't believe it s stress in the wood, I passed both boards on my jointer after this to straighten them out and they were nice and straight. But I've always taken car to store my tracks flat o prevent any damage. I will have to check it more precisely with another straight edge.
I've read on some reviews on Amazon of longer tracks (106 and 118) coming slightly bent in the middle down the length. So I knew that there was a possibility that some tracks either come bent or somehow become bent. Maybe my track did come bent an I didn't notice it at first.
 
I store my tracks on edge, transport flat. I wouldn't think a rail would bow under its own weight (on edge), but I could be wrong. Something to be aware of I suppose, perhaps supporting it at 1/3 intervals would disperse its weight evenly.

I have watched melamine close on the saw kerf as I've made a cut, resulting in a bowed cut. Weird that particle board would be under tension, but it was.

IMO- The piece you cut wouldn't continue to bow after a pass through the jointer. It's only a cut which releases tension in the wood.

One way to check your track without a straightedge would be to make two opposing rips and measure the distance in the middle. It would double whatever margin your track may be out.
 
I'm not a metalurgist, however the possibility of a rail sagging while being supported in the horizontal position is nil to impossible. A more likely scenario is that in the extrusion process, which is how these rails are produced, a defective rail was created and because in the present manufacturing acumen we seldom inspect at the 100% level, the norm is to choose a quality level you want to attain and then sample to that AQL.

Sampling to an AQL level will never eliminate outlyers. Outlyers will only be identified by inspecting at the 100% level.
 
dangav08 said:
I don't believe it s stress in the wood, I passed both boards on my jointer after this to straighten them out and they were nice and straight.

Hi,

  Welcome to the forum.

      You can check that by straight lining the board again using the rail and saw after you make the initial cut.  Just taking off about an 1/8th inch.  In fact you might not even need to make the cut. Just place the rail back down along the edge to see it conforms to the edge or if the edge of the board bows towards or away from the rail.

      Seth
 
Cheese said:
I'm not a metalurgist, however the possibility of a rail sagging while being supported in the horizontal position is nil to impossible. A more likely scenario is that in the extrusion process, which is how these rails are produced, a defective rail was created and because in the present manufacturing acumen we seldom inspect at the 100% level, the norm is to choose a quality level you want to attain and then sample to that AQL.

Sampling to an AQL level will never eliminate outlyers. Outlyers will only be identified by inspecting at the 100% level.

I am not a metalurgist, but I believe you are 100% correct.
 
yes [member=44099]Cheese[/member] - and I also worked with bunch of metallurgists, and they schooled me on young modulus.
 
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