Plunge Saw Advise

[AlexThePalex]

Dovetail, your reasoning and calculations are correct.

Only addition I'd like to make to them is that the max RPM of the TS55 is 5200 not 5000. When you enter that in the calculation you will find that a tooth on the TS75's blade runs roughly 20% faster than that of the TS55.

But is that 20% speed difference enough to make up for the number of teeth that pass a certain spot?

Because Allen is also correct when he says that double the number of teeth pass a certain spot with the TS55.

The TS55 comes with a 48 teeth blade and the TS75 with a 36 teeth blade.

Now lets assume the blade of the saw is running at full speed and the saw is not moved by the user, then for a set point on the workpiece:

with the TS55: 5200 x 48 = 249.600 teeth will pass in 1 minute.
with the TS75: 3550 x 36 = 127.800 teeth will pass in 1 minute

That means roughly double the number of teeth for the TS55.  

So the TS75's teeth move a little faster but there's only half the number of teeth of the TS55 cutting into the workpiece.

Does that mean these numbers have a huge influence on the quality of the cut? Not necessarily. As Dovetail reports from his own experience, there is little noticeable difference and I think first hand experience says more than some theoretical calculations.

 

[nickao]

Hey I remembered something from school!

Yes, when I was using both saws they both cut flawlessly and I agree any tool needs to be used to really know. Some of these specs we read on certain tools are laughable(net necessarily Festools) and don't mean much.

I do think that maybe the TS 55 is suited to plywood or a few pieces stacked and the the TS75 suited to harder, thicker woods and gang cutting of stacks of plywood, maybe that's how they could be differentiated for different uses.

I always preferred the TS 75, that's why I sold the TS 55.  I now do see  if only cutting plywood or just a couple stacked pieces for most of the work that the TS 55 would be preferable to some.

Both always worked great for me and I never grabbed one over the other to get a better cut when I did have both. I usually just used the TS 75, so that's the one I kept.

As you point out those are the stock blades and I think the 75 is expensive so they give the cheaper less toothed blade with it, I can easily throw on a 52 tooth blade on the TS 75.

I think its better to compare the blades with the same amount of teeth which puts the 75 at a closer teeth per minute as the 55, but I do see value in comparing what initially comes with the saw. Out of all my power saws the Festool are about the only saws I did not chuck the stock blade and get a new one right off.

I see how your calculations are correct, but I do not think that is what is most important in comparing the blades cut quality. I believe the edge speed of the blade plays a crucial role in it.  I believe(possibly incorrectly) you need to use the edge speed of each diameter blade to compare becasue the speed of the carbide passing through the wood will make a difference in cut quality. Generally, not always, in wood the faster the carbide slices through wood the smoother the cut, just as the more carbide passing through the cut produces a smoother cut. At least that is my experience in ply. I use the saw on its fastest speed to get the best quality cut in ply.  I think this idea of edge speed is why the TS 75 cuts as well as the TS 55 with a lower RPM in actual use. Well, its my thought on it anyway.

 

[JSands]

Since this thread will prob. float around for awhile.....

I will re emphasize what a few other posters mentioned....

I went with 75...glad I did.... the only reason I would buy a 55 is for.... single cut sheet goods, such as 3/4" thickness max.

The beauty of the 75 IMO it can handle 2 pieces of wood at once (certainly not overkill though, remember, these are 120V hand tools).    Festool squeezed as much power as posssible out of 120V hand tool in this saw.  And when cutting through 3/4" hardwood double stacked, the saw is at its limit, you are forced to reduce speed of cut....but its fast enough to prevent burns, so, IT WORKS!    Very impressive for making long straight cuts....

I have found, its rare I need ONE of something, two is common...to assure two identical sized pieces, I stack them make and make one cut.  This saves time, but it also ASSURES you two identical cut boards....  which is prob. more important to me, as the risk of mistakes, is quite costly in material.  NO matter how hard you try, its hard to cut to 2' x 6' pieces identical in size unless they are stacked cut.... to many variables that go askew.    This is most useful when you don't need a high precision dimension, but instead, you just want identical sized finished pieces.

so add that to your decision process.... 

the value of the TS55 is also weight, if you use an MFT, and cut thin sheets, the 75 is a bit big n heavy.... but that is non-issue for me, as anything small, I use a TS for.  So what you currently own also fits into the decision equation.    The TS75 is my sliding table saw, that folds up small and disappears...  We are not high production, so we are not cutting sheets all day, the TS75 w/ rails is really the ultimate portable Sliding TS replacement...  a well engineered and well thought-out product.

 

 

[ajones]

Jsands

sounds like you need the parallel guides

 

[JSands]

I do own the parallel guides, and they do serve a purpose but not here....

when I am ripping down a sheet or some long boards - it's one cut in the X direction, then another cut in Y dimension.....

If I have stacked sheets, I could not make all the X cuts with the parallel guides, or I would have to lift the sheet off after the X cut, move it, cut the next one, etc.  (and this assumes they are all the same X dimension)...with my system, I slide foam under two sheets layout lines, and make two cuts and have two identical pieces without moving the wood till its at final dimension.

Putting parallel guides on and off the rail would ruin the "convenience factor" of the entire cutting system for XY cuts.

I use the parallel guides when I need 2" strips, and 40 of them, its the perfect tool for that job.... or anytime you need the same width from the same board, many times, its worth setting up the parallel guides.

For me, most of my cuts are different X and or Y dimensions.... of course, sometimes I have a handful of the same dimensions such as shelves, in which case I use one of my first double stack as the measuring stick for the next ones.... ultra fast, and "almost identical dimension"....you might feel the difference with your finger when you align them, close enough for most ww tasks, specially shelves.    Anyway,  I "cut to the line",  and am assured my double stack will come out identical...now the only room for error is proper layout and assuring the bottom board does not slip, never happened yet, and when I am unsure I clamp'em...

Also, when working alone, I find it very difficult to rip 5 ft + boards through my cabinet saw.... why?  It's hard to push forward AND against the fence from behind the board.  So I often get saw marks on the board from slight changes in force, very fine, but now I need edge treatment, which also changes width... so I must account for this a bit.... with the TS75, the cuts are identical and never need treatment, although I always keep the blades sharp which helps keep the cuts ultra clean.  Now, a second person, or some jigs on the TS can change this equation a bit.... but I work alone quite often.

Even going a step further..... I no longer edge join long boards on my 12" joiner, (again 4ft range and longer)...Instead, I lay the rail where it needs to be,  and a "single" cut, faster, perfect edge (vs. tons of swipes on the joiner)  ..... then, draw a few width lines, mark long rip line, set rail, and cut.  Now two identical sized boards of perfect rip dimension ....  its the easiest method I have used.... no more changing joiner blades from edge joining, which wears the blade near the fence, making face joining uneven.  The rails solve this problem as well.... sort of "joiner blade savers"...    Much of the hard wood I buy, needs a lot of edge joining...getting rid of that swipe, swipe, swipe task has saved my wrists, arms, shoulders, etc. as some of these long boards can weigh 40+ lbs...

Thanks for caring Festool 

 
IMO, I don't think the Festool rail system is marketing well....it can do so much, but many people never think of many of the applications.... luckily I learned from a few Festool employees... who are more than helpful.  This tips have simplified, improved, sped-up,  and have reduced potential for errors in my workflow....  Kudos to Festool tools, AND Festool employees, in this case, its a mix of a great tools and great application of the tools which requires some education....and no, I have not drank the Green Kool Aide... I have lots of tools from many different makers.... When Festool is the right tool for the job, I buy it, use it..... 

 

[JSands]

to make my position complete...I left this out...

when making long cuts, IMO, a single long rail is imperative to assure straightness....
while you can join rails, the cuts are not assured straight, as even when you set them to a long straight edge, they move when handled often, and only a slight movement can throw off your straightness....which is what makes the system so great...  this is important, and at $300 for a long rail, it sure adds to the costs, but now you will always have extremely straight cuts.  Of course, this is best in a shop, as these long rails can be cumbersome to bring to a job site...

 

[Ken Nagrod]

I haven't had any problems keeping joined rails straight.  There's definitely an extra time factor in checking the joined rail combo for every cut, but it works fine.  I know with the longer FS3000 and FS5000 rails, it's more difficult to get a perfectly straight cut out of them because the aluminum extrusions are so long and allowable tolerances are a factor.  As an example, how many of you have the FS3000 and know that it's 1/32" out in the middle.  That's within Festool's tolerance, yet when you cut a sheet of ply down the 8' length twice per cutoff, your piece is now 1/16" narrower in the middle than at the ends.  Does that matter?  That's for you and maybe your customer to decide.

 

[JSands]

Valid point Ken... 

I prob. got lucky with my long rails, as they are out way less than a 64th over 8ft....  never bothered to check how much, as that is pretty damn good....but at the same time, others can get long rails that are further out, but yet, still within Festool Tolerances...  where did you get this Festool "tolerance value"  ?

My problem with joining rails was, during multiple cuts, it appears that if one person sets the rail on-end too hard, it would rock the connection just a tad, but when that connection is in the middle, it can throw the cut off dramatically...  I found myself constantly checking to see if the rails moved....    A lot of this comes down to, who is doing the work....if its just "you" and you  "as a Festoolian" are constantly aware of these issues, chances of errors are less likely.  If you get a crew started, and then turn it over to them, it seems few care as much as us about these details...  more probability of errors...

 

[Ken Nagrod]

David McGibbon at Festool told me they were in acceptable tolerance at 1/32" out.

 

[tbellemare]

If I take a 3-meter long, thin piece of aluminum, it is going to flex.

If that piece of aluminum has various structural components that will also help keep it aligned, I might be able to make a straight line over 3 meters with that tool...

Tom

 

[JSands]

1/32" over what distance?

Also, the rails "rail" or "hump" is a good, but not perfect, means to keep the rail straight.... Of course, within the limits of the real world practical use for what they were intended for... ya have to treat these rails gentle...

I think Festool designers were balancing weight considerations vs. rigidity.   

 

[Ken Nagrod]

We were discussing the FS 3000 and FS 5000 guide rails.  You'd have to ask him about the acceptable tolerance on the shorter length rails.

 

[JSands]

so on the 3000,  1/32nd / 10ft is 1/320th, or .003" per ft, decent....

on the 5000,  .002" per ft.... even better.... 

from my experience, they are prob. closer to 1/64th...

Problem is, my Starett Straight edge (the longest straight edge I own) is only 6ft...
hard to find a suitable reference edge...

 

[Ken Nagrod]

David was saying that 1/32" variance over those longer lengths is acceptable from the aluminum extrusion process.  He didn't state what the tolerance was exactly.  A spec like that might have to come from Germany.

 

[tbellemare]

1/32" is 31 thousandths and change. That's not much over a long distance, especially if the object being measured is not milled.

I have designed a lot of metal parts where +/- 15 thousandths was the default tolerance for machining. I wouldn't consider 30 thousandths to be out of consideration for a 4' extrusion.

Absolute dimension definitions help the manufacturer and the designer meet the requirements of the tasks for which something is intended. Using that method, the overall requirements are defined and the mfr. is allowed more leash. If David is referring to an absolute dimensional requirement, it makes sense that the length of the rail doesn't matter.

My experience with Festool Guide Rails is that they are really accurate if used properly and never abused prior to use. As I stated in a previous post, I can bend aluminum. If the rail, which has a sticky strip component on the bottom, is place on the work piece under stress, it can be crooked. The key, even with shorter rails, is to relieve all stresses as they are placed on the work piece.

Tom

 

[Ken Nagrod]

1/32" is 31 thousandths and change. That's not much over a long distance, especially if the object being measured is not milled.

I have designed a lot of metal parts where +/- 15 thousandths was the default tolerance for machining. I wouldn't consider 30 thousandths to be out of consideration for a 4' extrusion.

Absolute dimension definitions help the manufacturer and the designer meet the requirements of the tasks for which something is intended. Using that method, the overall requirements are defined and the mfr. is allowed more leash. If David is referring to an absolute dimensional requirement, it makes sense that the length of the rail doesn't matter.

My experience with Festool Guide Rails is that they are really accurate if used properly and never abused prior to use. As I stated in a previous post, I can bend aluminum. If the rail, which has a sticky strip component on the bottom, is place on the work piece under stress, it can be crooked. The key, even with shorter rails, is to relieve all stresses as they are placed on the work piece.

Tom

Who's gonna pay for all that therapy or should I play one of those crashing waves cd's for my guide rails?

 

[tbellemare]

Go to Hawaii...

Tom

 

[andvari]

A 12' straight edge for checking runway flatness goes for $1500 or so. It is spec'ed +/- 0.012" Maybe with one of these you could get the straightness you are looking for.

 

[JSands]

>  A 12' straight edge for checking runway flatness goes for $1500 or so. It is spec'ed +/- 0.012" Maybe with one of these you could get the straightness you are looking for.

           
                      Not sure who you were responding to....but if it was me, as I wrote above, I am more than happy with my 64th over 8ft, for the cost of the rail, ya can't ask for more in ww......  possible you were responding to another poster, or did not read the thread....

But I am curious of the straight edge you refer to of that length and cost?  Got a link?   
My guess is, at 12' it would be hard to keep the straight edge "straight" as just the weight of it alone would make it change dimension a bit...?

 

[mouppe]

Piqued my interest so I did a search on the subject...

http://www.concentric.net/~Petsch/Runway/RunwayStraighEdge.htm