Hole system rail modification

Julian Tracy

Member
Joined
Oct 25, 2007
Messages
529
Has anyone ever tried to modify their standard 50" rail with the holes need to use the shelf drill jig?  Sure, you wouldn't try and do your own shelf drilling on a regular basis, but wouldn't be too bad to precisely drill out one rail once to create a dual purpose rail, right?

Or, is that sacrilage around these parts?

I'm new here - bought the Domino earlier in the year for a staircase job, and have just picked up a 55, trion, rotex and Ct22.

Seems kindof "not smart" to have to buy another guide rail when they could have easily drilled them out at the factory...

Or -is there something different about the rails other than the holes?

Julian
 
Hi,
 
        I think that if you set up a drill press with a hole and pin in the DP table insert (or sacrificial piece) for precise indexing. Then drilling a guide rail to use with the hole drilling system would be pretty quick and easy.

Seth
 
I have had the same (negative) thought about Festool not making all their rails, or at least the most commonly used sizes with those indexing holes including those packaged with the MFT 800 and 1080 and TS 55.  I haven't used my "holed" guide rail in a while, but I believe those indexing holes on the factory machined guide rails are not round but rather are slightly oval.  I have not studied why that is so, but there has to be a good, logical reason, or Festool would not have adopted what has to be a more expensive procedure.  If I am correct, drilling your own could become problematic.  I suggest you carefully inspect one of Festool's indexing guide rails before making your decision.

Dave R.
 
I suspect that the holes are oval because the clearance between the hole and the pin is so small, that having a perfectly round hole would mean that the distance of the pin from the 'guide' part of the base plate would become critical. Any slight variation, through the manufacturing process or wear, would mean that the pin wouldn't hit the hole.
 
Hi,

        Yes, oval holes could be a problem.

Seth
 
If you think about the processes necessary to make a rail then it is not that difficult to understand that the shelf pin holes are a completely separate operation. The rails are extruded on very specialized machines, followed by a cut to length operation, probably very near the extrusion machine (a guess). The shelf pin rails need to be processed on another machine, perhaps a vertical machining center and in the case of the longer rail a machine with quite a bit of travel (read: not cheap). Also, the overall length needs to be held very accurately so that we can work from either end with confidence. I have not looked at the indexing mechanism on the baseplate to see why the holes need to be elongated but I can guess that Festool is endmilling the holes oval for an added level of accuracy, end-milling being more accurate than drilling, and to also remove any burr left from drilling through the extrusion. These are what I would consider first rate machining practises and they come with a cost. Why not do all rails? Probably because some of us would complain about having to pay for holes we don't need and also because ALL rails would need the extra processing, thereby creating the need for more machinery than already allocated to rail production. I am willing to guess that less than 10 percent of the rails are shelf pin drilled. Drilling the other ninety percent would be pretty problematic from a production standpoint. I am pretty amazed that they do drill a longer shelf pin rail because this is well beyond the capacity of most machining centers. It would seemingly be cheaper to encourage us users to buy two shorter rails and combine them if we want to go longer.
 
gregman I disagree, combining tow short rails is a pain because the spacing on the end holes is not exactly 1/2 you would have to leave a gap between the rails and then if you are not looking the router will index in that gap.  Also when you set up the rails you need a inch or two overhang on both sides to deal with there clamps and spacer if you want to set it up the fest tool way, you also don't use the first few holes because I usually start a inch or two into the work piece.  This means that the capsity of the short rail is much shorter than you think.  I had to get a long rail for this to be useful, which is still not long enough do a 8' piece of plywood.  When set up right the holes it makes are perfect.

I did write Festool when I got this system asking why they don't drill all the rails for the price of them and the answer above is correct it would cost more to do so and only a small percentage of people use the holes.  I was trying to think of a way I could use one indexing rail to drill another then you just shift it out a bit redrill (router) to make the hole oval.  Never did but if anyone tries this please post. 
 
Due to the holes being oval, you'd need to use an end mill as Greg mentioned.  This would be fairly easy to do if you had a vertical mill with a digital x-axis readout and the appropriate size mill (bit).  The hard part would be indexing the holes from the end (aka determining the proper spacing) and then re-indexing the whole rail once you reached the end of the bed's travel.  Most vertical mills have about a 50" travel, so you'd need to move the rail at least once, possibly twice depending on the size of the mill.  This could be why the longest rail they offer is only 95".  That would let you create this rail with only one adjustment of the mill.  I would think that any good machine shop could modify a guide rail for you, but it's going to cost well more than the $237 Festool wants for the 95" rail. 

That being said, I'd still prefer they sold the 2700 or 3000 with holes since I'd like one of those but I also want a longer rail than the 1080 for my LR32.  I don't wish to spend another $500 on rails just so I can have holes and a 2700.  I'd pay another $75 on top of the $212 for a 2700 LR 32 guide rail.
 
As I now understand it, cost is the problem, not the availability of machine tools.  My employer has some large multi-station machine tools (made in Germany) that can handle parts at least as long as those long rails.  Have you ever seen the 17' tall landing gear for an A380?  Or the landing gear for a B747?  These machines have precision tables large enough to process 8 landing gear main cylinders at once.

Dave R.
 
On a modern CNC milling machine adding the holes (even oval) would be an operation taking only a few minutes costing perhaps $20 (depending on thier "overhead rate")

For the amount of money they charge, it should be included as standard.
 
hazmat said:
For the amount of money they charge, it should be included as standard.

But not everyone wants the holes.  Do you think that if they provided every guiderail with holes, somebody would complain that they didn't get the full compliment of aluminum?  Or that they were getting charged for machining holes when they had no use for them?    :D :D :D :D  ::) ???

You could go crazy trying to please all of hte people all of the time.

Just my $.02.
 
Milling the holes on any CNC mill could be very fast; up to the point of running out of travel. Then it becomes a pain getting accurate continuity. Dave, you are right that there are machines out there that could easily do this in one step but they are very expensive machines. Any machining center with 100+ inches of travel will probably cost the high altitude side of a half-million and, more importantly, would be totally out of place in a company making hand-held power tools. My original point was that adding the holes was an entirely extra step in the manufacturing process and done on equipment not normally associated with aluminum extrusion work. For all I know, Festool may farm this out. As I type this, there are 30 such machines on the other side of the wall, any one of which would be capable of milling those holes in the short rail in about 5 seconds per hole at most, meaning I could probably do Festool's worldwide requirement in one day each month. They could probably be machined about as fast as an operator could load the machine, but that would have little to do with the true cost of adding the holes. What do I do with the machine for the rest of the time? In addition, none of them have enough travel to do the long rails. These are machining requirements that are just a little out of the norm for a company whose machining challenges are primarily electric motor armatures, small die-cast housing and such. The LR32 rails are really niche products that Festool offers to bring value to their line.

As far as joining two short rails, P-Geek, I really did not research its practicality when I mentioned it. My bad.
 
greg mann said:
As I type this, there are 30 such machines on the other side of the wall, any one of which would be capable of milling those holes in the short rail in about 5 seconds per hole at most, meaning I could probably do Festool's worldwide requirement in one day each month.

I dunno Greg, sounds like you are offering to mill the holes in our rails for us. That's awfully nice of you. :)
 
Sure Lou, as Click and Clack, the Tappet brothers would say, "Send it to me in the backseat of a 2007 Audi A6 with......"  ;D
 
Back
Top