118" Guide Rail-- uneven cut??? Help?

[wnagle]

Just letting everyne know,  I talked with Ron Pegram from Mcfeely's about my rail... Bottom line, a new one is on the way right now.  More than I expected and a salute to Mcfeely's and ron! 

Thanks Ron for all your help!

 

[fshanno]

Hello,
I'm using the 118" guide rail for the first time. I'm getting uneven cuts on 3/4" MDF. The way I would describe it is it's bowing outward in the middle and touching on the front and end of the cut. I'm attaching a photo. I've clamped the MDF and the guide rail and the results are the same. I'm a little alarmed this is happening. Any suggestions?

Any suggestions?  I suggest you stop messing with my head!

I just came across this thread and I hate it!  Can't we let sleeping dogs lay or lie or whatever?  My beautiful 106" guide.  The cuts look straight.  I build cabinets with it.  The cross diagonals are the same.... mostly.  If I can't get it replaced then I don't think I want to know if it's bowed but doubt as crept in.  How can I get a square crosscut with a curved reference edge?

You know what I think?  I think you rigged up some evil jig that makes super long radius arcs just to yank our collective chains.  And it worked didn't it?  Better than you could have hoped.  Even Woodshopdemos fell for it.  I can hear you laughing.  I hope you're happy.

I'm going now to check it and if it's bowed I'm blaming you Intermod!

 

[fshanno]

I'm back from testing.  If there is a bow it's tiny.  I tested my 2700 and 1900 with tensioned lines and against each other back to back and then flipped one and they are straight.  Still and all and such is the mania that I will be keeping a close eye on this.

At any rate your evil scheme has worked.  The seed has been planted.  None of us will ever look at our beautiful guides in the same trusting way again.  I hope you're satisfied. 

And just for curiosity's sake, tell me, how did you get such a perfectly even tiny little curve in those boards?  I know!  You used a CNC router didn't you!  Clever, very clever!

....... and stepping out of character now.  This is a real eye opener.  I had always taken it as an article of faith that the guides were straight.  I only worried about splices.  I'll going to make a version of that jig and test the long guides periodically from now on.  Also I'm going to take that advice about being very careful with my guides.  I'm sorry this happened to you but it may turn out to be good thing in the end.  It will encourage a good new habit.  It's an ill wind as they say.