LARGE BIG TS Sled w two guide bars OR against Fence ??

[Marc Jeske]

Still digging through Google images and Youtube videos.

Have 45 ? yr old PM Contractor saw w 52" Biesemeyer.

May be upgrading in future to D/R 12/14 w Bies 52 .. will decide BEFORE I do any "permanent" ext table design/ install.

It stays stationary and never has to move... Plenty of clearance ALL around.


Want to regularly crosscut one foot of length off of 16" x 8' panels...so end up w 16" x 7'.

I purchase them at already 16"... Factory ends may not be perfectly square.


First question - Why do I never seem to see sleds that bear against the Fence as the guide ?

Always they use the miter slot.

Remember, in my case I am only cutting off one foot to the right of the blade... not something over the "52" " reach.

Seems to me one could make a sled w an extended fore to aft right edge that would seem to work.


Second question - How realistic is it to make a sled that uses BOTH slots w no bearing on fence ?

Concerned about binding in a fluctuating ambient humidity.


So basically I am brainstorming about making a poor mans equivalent to a Rolling Table or Euro panel saw really mostly kinda only for the job described above.

Commercially available like Excaliber, Sawstop etc "Sliding tables" are too expensive for my taste.. especially not being very large.


Currently, I use a dedicated piece of ply 8' x 2' w a back fence and 90 deg guide bar I run the little PC worm saw against.

Works fine but would rather be able to do on TS.

I do have the floor space around the saw no problem

Lastly.. I have learned occasionally on some large panels to sprinkle a tiny bit of blasting Potters glass beads to act as microbearings.. works great for occasional work.

So for the not often I need to do this, that could be employed in addition to good waxing.

I will be building ext tables around infeed, left side, and out.. so my left table will support this sled.

Comment please.. mostly on the two specific questions to start with.

I think I gave all pertinent info, please read carefully.. if not.. ask.

Thank you all very much, Marc

[Ken Fitzgerald]

Answer to 1st question, I adjust my fence so the far side splays to the right a couple thousandths so boards can't get trapped when I am ripping them. I wouldn't want a sled riding against the fence.

Answer to the 2nd question, my sleds do use both miter slots and don't use the fence.

Lastly, personally, I would not use glass beads as I would not want to take a chance on inhaling any or any particles they might generate if they accidentally came into contact with the blade. I wax the tables on my T/S, B/S and scroll saw.

[Tom M King]

Sorry, I don't have an answer about the best way to make that cut on a TS. I would use a RAS. No way would I feel comfortable making that cut on a regular TS. I'd make a dedicated rack to cut it with a circ saw, if I didn't have a RAS.

Is your PM contractor saw a model 62? I still have one that I bought new then. I've never seen another one.

[Brian Holcombe]

Sprinkling glass beads is going to destroy the machine, it would be prudent to discontinue that practice.

[Marc Jeske]

The glass beads never get within a foot of the blade.

They are used very methodically in extremely small quantity...less than 1/8 tsp.. Never used for repetitive cuts where they would in that case migrate "everywhere" including blade.

So ya, NO problem.

Tom M .. Pretty sure it is a #62 AFAIR.

And, I did say I already currently use a dedicated "Rack" w a PC little circ saw.

Ken... RE inhaling... I have given now more detail on the use of them in this post.

My Daughter in Phoenix inhales more Silica in ONE day during their "Dust Storms" than I will in a Lifetime.

I choose to leave my fence closer to parallel.. not perfectly... but close enough to ride against for realistic "90"

Please talk about a sled using two slots works out if in fluctuating ambient humidity.

Interested in that.

Marc

[Marc Jeske]

The glass on table, the < 1/8" tsp.. is swept off to the left after rare use.

It is ONLY applied to left of blade... NONE to right of blade..NOT within 1 ft of blade... and VERY sparingly.

Not like when I eat Spaghetti and use 1/3 jar of Parmesan !!

Marc

[Marc Jeske]

Tom - Thing is... I need to do the same thing on my 28" Casket lids as the 16" sides.

RA is too small a reach.

Marc

[Cary Falk]

1) A sled that rides against the fence can rotate out into the blade and bind then kick back. This would be even harder to control with a 7' board hanging off one end. No way I would want to use the table saw. If you have the room find a DeWalt 790/7790 with a 16" crosscut for $100-$150 and use it. If you don't have the room. Make a jig that you quickly rreference and cut off the piece.
2) People use 2 runners on large sleds all the time.
3) No way would I want glass bead near my tools. A good wax should be good enough.

[Lee Schierer]

Want to regularly crosscut one foot of length off of 16" x 8' panels...so end up w 16" x 7'.

First question - Why do I never seem to see sleds that bear against the Fence as the guide ?

Always they use the miter slot.

When you put your panel or a sled against the fence you have no garuntee that it will stay tight to the fence. The drag to the long side of the piece will tend to make the piece want to twist as you slide it across the table. As you know any binding not only ruins your cut but it can be dangerous.

With runners in one or more of the miter slots the crosscut sled cannot twist relative tot he blade, hence no binding and no kick back. You can use a stop block or short fence to set your cut off length for repetitive cuts.

Waxing your table surface will make the sled slide more easily and also helps keep your saw table clean and shiny.

[Peter Christensen]

As I understand you, using the fence to run the sled against over time, because you can't always get the fence in the same place every time you use it, your blade slot gets bigger and bigger. That would provide less support beside the blade increasing the splintering of the cut edges. As Cary said the sled can come away from the fence and kickback. That could be overcome by having a U shape on the end of the sled that fits over the fence but you still have the problem of locating the fence.

The two runners work fine especially if you keep them waxed. If you have a seasonal humidity problem make the runners out of something that doesn't get affected by moisture. Corian, UHMW (the 3/8" x 3/4" x 48"LV sell for example (http://www.leevalley.com/en/hardware/page.aspx?p=32045&cat=3,43576,32045)) steel bar stock, pre-made runners http://www.leevalley.com/en/hardware/page.aspx?p=61986&cat=3,43576,61994,61986 or http://www.leevalley.com/en/wood/page.aspx?p=65247&cat=1,43455 .

I wouldn't use the glass either. Talcum power if anything. I have never needed anything more than paste wax or a wipe with a bar of canning/candle wax. Don't use Pledge or similar. They have silicone in them that plays havoc with film finishes.

[Ken Fitzgerald]

Marc,

Where I live we get 13" of moisture annually. Fluctuating humidity is not much of a problem but you don't have to use wood for the runners for the miter slots. I use quarter-sawn wood, finish the miter runners and the bottom of the sled. Then I wax the runners and the bottom. My poly finish is thinned and still has the desired effect.

For the record, my fence is very close to 90º to the rail end but 0.001-0.003" at the far end of the fence isn't going to cause much of a problem at the blade where the ripping takes place.

[Ken Fitzgerald]

Marc,

where I live, we only get 13" total annual average moisture so relative humidity has little effect here. You don't have to use wood for the runners but I do. Then I put a thinned coat of poly on the bottom and runners followed by a couple coats of wax.

My fence is very close to 90º as 0.001-0.003" at the far end of the fence has very little effect at the front edge of the blade where the cutting is taking place when ripping.

[Rick Potter]

Sounds to me like a good use for the Festool track saw with their MFT, or, heaven forbid, the new Kreg track saw and table setup.

[Marc Jeske]

OK, so consider me argumentative.

Pretty familiar w the issues explained above.

Been there ... done that.

I have crosscut one foot off the end of many 4x8 panels along the fence w minimal trouble....

HENCE - Why can't I build a sled w a over length... lets say 4' edge that rides along the fence ?????

Please think about that before giving an answer to it.

Marc

[Marc Jeske]

Rick - Again... I already have a dedicated jig as I clearly described above to do the equivalent of this.

Marc

[Marc Jeske]

Again... consider me a Jerk if you must .......

But I REALLY wish Folks would read posts more carefully before replying.

Respectfully... Let's talk like Engineers... NOT like a teenage "Chat" line.

Marc

[Peter Christensen]

OK, so consider me argumentative.

Pretty familiar w the issues explained above.

Been there ... done that.

I have crosscut one foot off the end of many 4x8 panels along the fence w minimal trouble....

HENCE - Why can't I build a sled w a over length... lets say 4' edge that rides along the fence ?????

Please think about that before giving an answer to it.

Marc


I thought about it before writing my answer in post 10.

You can't get the fence in the same place every time you use it. Your slot will get wider so you get increased splintering.

Obviously that didn't sink in or you dismissed it as unimportant. Do as you wish. I won't waste my time trying to help.

[Matt Day]

Your situation is what sliding table saws excel at.

Your questions have pretty much been answered I think.

Take it easy on the attitude.

[Dan Friedrichs]

HENCE - Why can't I build a sled w a over length... lets say 4' edge that rides along the fence ?????



You can. It will be inferior to a sled that uses two miter slot runners because it can tilt into the blade. You seem concerned that it will bind due to humidity. Several people have told you that's not an issue. So - why not just do that, instead of what you're proposing?

[Marc Jeske]

Peter - "You can't get the fence in the same place every time you use it. Your slot will get wider so you get increased splintering."

Agreed.

So you are saying my sled bed will no longer act as a zero clearance plate.

No problem - No issue in my situation... my specific production.

Tearout is hidden by trim... other edges are gently beveled enough past tearout.

Marc

[Marc Jeske]

You can. It will be inferior to a sled that uses two miter slot runners because it can tilt into the blade. You seem concerned that it will bind due to humidity. Several people have told you that's not an issue. So - why not just do that, instead of what you're proposing?

We know that using HDPE, Al, steel, .. or "similar" non affected by humidity change compared to hardwood however well acclimated will give a more stable jig.

Even if I use impervious runners, my BB base will still slightly change w humidity.

When a few thousands change will cause binding when using TWO runners.. this is my reason from staying away from that method.

Unless there is an solution for this problem I am unaware of.

I am also familiar w setscrew adjustable bars... that MAY be the answer.

Marc

[Keith Westfall]

Marc,
You come asking questions and for advice, but when it is given, you state that you have done it the way your doing it and it works. Then just do it that way.

Many of us use the 2 runner sled and most do not have any problems. If that doesn't work for you, then build you fence sled and get on with it.

There is a thousand ways to skin a cat, so if you don't like others way of doing things, do it your way, but remember we don't have to like your way either.

There is a lot of smarts on this forum, but NO ONE has all the answers. We do what works for us, and pass along suggestions. I don't imagine that anyone looses too much sleep when one of our suggestions is not used.

Enjoy what you do, and do it how you want to. Don't chews heads off because someone disagreed.

[Marc Jeske]

I apologize for being coarse.

It was a rough day.

Will start fresh tomorrow.

Thank you all.

Marc

[Mike Nolan]

BB plywood does not expand enough to bind due to changes in humidity. That why I can use a two runner sled. In my opinion even a one runner sled is better than a sled guided by the fence.
The fence isn't as rigid as the slots.
On my saw the blade is parallel to the slots.
If your sled is merely against the fence then it has to be held there through the cut.
If you have been successful cutting full sheets using the fence then you can probably make a bigger sled work. But IMHO it would be a lot easier with a one or two slot guided sled.

[Dave Cav]

I have a Delta Rockwell 12/14" table saw. My sled is about 28" deep by around 36" wide. The base is 3/4" plywood, the "sanded pine" stuff from Home Depot, not ACX or CDX. The runners (2) are 1" aluminum bars, and the front and back fences are cut out of 2x stock. It is a bit heavy but it works fine.

[John TenEyck]

I built this large sled 23 years ago when I built my kitchen:

https://lh3.googleusercontent.com/if2Lu7QR4fwYAAxv1hLyipvxPjXWssd9QTDQs1JHb0MFPC-vXtK3JTZ7_fjsOMYqfV_5GSX1viWrZixNITPideGoHGXCVxhWv 6AZurMKCxukqxrxjeCX0eQrheRMG8EF_Wl0k577dDDXUZLMO6c hGqq4d4hehbaEokRpm2OF5cnCrUIat4hlXfoV9xQ8Xsj1xrOND tGj_5UNJ42ATZKDISdoxPpIaMaP4a_8egfhoR31aRp-VAAnTGD0-wEg1ZmNRZVmzqSPRgi8mkBnyLwtWYhxAyDfW3e2HsdQKUOHnrK 4o29d5iXDWnBLKipONCqqNe5wpvPI4sFQ7_ttCD_YowuPNBPwT ZwzOyMWmTw0AjKWJdmCB17CvdkFHTJLBWxCYEBYEV64cwZ6yWt MDg2rw_THKYraqTjJfoG7Rwe_NUziVKTJNZVihlApRh8yrwhvv _RMBgPDf6_H85k3VMPecZtnP0mbBqiYasygGxQpZ2hQJMRObh-ZgAktd6ULft50BXdsx6l7GBlPTQ7owWqybpx9jSx5GvX4lYkvn sTUlyxa6fnQy0UyUbbwaZJGZHsjEoFi3seFV5b38-EXAH8ErZjEuIdf-dn8dNgjiSjTrgZ9IvKUTcCEgiksfTKZwgBARXCU-rDfgna6peqPMLJHqdTd8_RBnvy9mK70_fMqxTmzieOVM-Q9gf2Y9GfSRGaSmgHZRBO8jV_y_NpHXtKTY_GoZw=w835-h626-no

It's 48" wide by about 40" deep. It rides on two maple runners. Once I got it tuned it has never needed adjustment; I just wax the runners a couple of times a year. The RH in my shop goes from 55 - 30%. Maybe it would be a problem if the RH had a wider range but aluminum, UHMW, etc. would resolve that problem. I know you said your parts are only 16" wide but the deeper the sled the easier it is to get it tuned to exactly 90° and the easier it will slide. Also, whatever you make you should include a top shield like you see on mine, and a guard at the back for the blade. The shield not only keeps dust from hitting me in the face, it also acts as a reminder of where not to put my hands. It might save me, too, if I fell over onto the saw when it was running. You'll also note there is a ZCI, which can be replaced as needed.

John

[Jacques Gagnon]

Marc,

I have read every post and I have been using a two-runner (made of hardwood) sled made more than ten years ago. No problems with large seasonal variations in humidity.

Given that your preference appears to be the use of the fence as the positioning device, here is a suggestion that may work.

If you added a box that straddles the fence at the end of your sled, you could probably push the sled without the twisting action mentioned in some of the previous posts.

Your sled led would need to be «longer » , in order to be able to attach the « box ». You would also need front and rear fence - as is the case for most sleds - to hold everything together.

In other words, if your box added a total length of 1 inch to your sled, you would position your fence at 13 inches from the blade in order to remove 12 inches on your panel.

Hope this helps,

J.

[David Utterback]

I have also used a double runner sled for years without any binding problems in a basement shop with large humidity changes.

In case you have not understood others, the use of glass beads around precision machinery is ill-advised. Unless they are scrupulously controlled in an indoor space, they are likely to spread everywhere and deteriorate bearings and any other metal to metal moving surface. Machine shops use them in glove boxes for a good reason. And you should also understand that it is the smallest of the silica particles that are most damaging to your lungs and the machinery. Comparison with ambient dust in the desert is not valid.

Hope you can stand to be corrected and take the input of others in the way it is given - with the best of intentions. Otherwise, you might want to change your byline.

[glenn bradley]

HENCE - Why can't I build a sled w a over length... lets say 4' edge that rides along the fence ?????

Please think about that before giving an answer to it.

Marc

You can. I prefer the control of the runners. This means all my focus is on material control and forward movement. The runners relieve you of having to pay attention or spend any effort keeping things moving in a true path.

[Mike Kees]

Marc,forget about building a crosscut box that rides against the fence. When you tune your saw the blade should be aligned exactly to your miter slots (parallel). If you build a crosscut box that uses a runner or runners it will be more accurate and as others have stated easier to control when you are cutting. I had and used a crosscut box for about 15 years. Then I owned an Excaliber sliding table,it was accurate and worked well with some extra "engineering" on my part. The main issue was the legs needed to be held in place on the floor to maintain accuracy. Then I bought a Minimax Sc2 slider,huge step up. Every one of these worked but every step up was a big increase in efficiency and accuracy and speed. I think that your best budget option is to take the advice of the poster who said get a RAS. 2. build a sled with runners for the miter slots. 3. Excalibur 4.Slider. My best advice is to make it work and save money for a short stroke slider . Skip the other steps (Excalibur),you can thank me later,Mike.

[Marc Jeske]

OK... LOTS of great comments.

Gonna re read and ruminate this awhile.

On the same quest for cutting larger panels.. I was planning on a left permanent extension table..

But now I am wondering - If one has the floor space... "why not a 96" Biesmeyer ?" .... posting new thread that title now.

Thank you ALL very much, apologize for any crabbiness on my part.

Marc