Permanently mounting table extensions

[rjwaldren]

I have a 21829, that I'm thinking of upgrading my table extensions on. I currently have a shopmade left miter slot attached to the rails, but I move the rails too often.

I've seen several designs here that look to be attached directly to the flat wings on the front and back faces of the saw box, allowing free movement of the rails without needing to realign the miter slots to the blade. Are there any problems with that idea? Is the sheet metal strong enough to keep it from tweaking in use, say with a dual runner crosscut sled?

My new left extension would be roughly 6" wide and mounted only to the flat portions of the front and back faces of the saw box. The right extension would be 12.5" wide and add ply supports attaching to the saw box to provide additional support to the outer edge. The material will be laminated MDF. Once shimmed/aligned I doubt they'll move again.

[steve-norrell]

The Ryobi dual slot miter tables mount on the saw casing but I believe most other add-ons attach to the rails. It would not be very difficult to design attachments, similar to the extension table mentioned in your post, that attach to the casing, but why?

I have had a BT3100 for a couple of years and have never moved the rails since installing rail extensions. Even before getting the extensions, I rarely moved the rails.

I have made a miter table that rests on the flat wings on the front and back casing, but they are affixed to the rails to hold them in position. I have also used the accessory table that attaches to the rails. My shop-made router table is attached to the rails.

An interesting question - - I look forward to some suggestions.

Regards, Steve

[rjwaldren]

Thanks for the response Steve.

The reason I move the rails is that I don't have an extension kit. For my space/use I only aspire to add about 12" to the rails, so I may pickup a half rail set and chop it in half at some point. I've also moved away from the rail mounted router table so moving the rails where I need them is no big deal - save for throwing the current rail mounted miter slot out of whack.

[Uncle Cracker]

I used to move the rails a lot, too, but after getting the rail extensions, I don't have to move a thing. Changed everything for me. You might consider it more strongly, rather than reinventing the wheel to avoid it.

[Slik Geek]

I used to move the rails a lot, too, but after getting the rail extensions, I don't have to move a thing. Changed everything for me. You might consider it more strongly, rather than reinventing the wheel to avoid it.

Ditto for me. Couldn't have said it any better.

[JR]

I don't use raile extensions on my old BT3000 because I don't have the space. And I regularly move the rails for a variety of reasons.

The stand BT3000 has a little deck on each side, protruding beyond the sides of the saw body. Any support for add-ons can rest on this deck and be attached to the saw body. I don't know how the 21829 is configured in this regard.

In any case, you could create triangular l-brackets for your problem. It would be possible to tap the sides of the 21829 case to mount these brackets, but you might find the skins to be a bit thin if there is no other support available. In which case, a nut epoxied to the back sid or the skin might do the trick.

A word to the wise - you probably won't the assembly built perfectly, so expect to need some room for minor adjustments. The brackets should have mounting holes cut a little oversized. This would allow the assembly to be adjuste for height, resulting in perfect alignment of the table top with the top of the saw.

JR

[rjwaldren]

The 21829 has the same wing configuration as the earlier models, so resting on those "wings" is exactly what I plan. The side triangles will be connected to the ends of the front and back faces rather than straight to the right side, that would be a weak surface as it flexes with a finger push. Flat head 10-24 machine screws with nuts to mount and threaded inserts in the right side supports. The top will have oversized holes to allow adjustment. The materials I have glueup end up 3/16 too tall so I'll sneak up on the right height with dados to surround the "wings" and hopefully not need to shim much.

I do understand the points raised about extension rails, but for the time being it needs to stay mobile and foldable. I normally have it set up with the miter slot and SMT to the left, that requires moving the rails and removing SMT to store it. The left side on the 21829 is the side that tilts to the floor when folded and the SMT stores on cleats on the back covering the dust port. If not put away correctly the rails will smack the concrete when you fold it.

I had intended to be well along with a mobile base that would have solved some of my space issues and the right side table issue. But a vacation that was meant to be spent in the shop turned into a 4 week bout with pneumonia. That and life in general have dictated that project will be postponed behind many others.

[JR]

It sounds like you've got a good handle on things.

Good luck!

JR

[rjwaldren]

Well, I did it. They are sturdy and give me a 23" inch flat work surface permanently affixed. On the right side, I ended up with a 10" wide extension. It was originally 12.5" but I cut it down to move the weight back over the saw body. That eliminated the need to add bracket style support to the overhang.

I got in a hurry on the left side and I'm unhappy with my work, but the table works fine it just has some visible screwups, requires more shimming than I'd like. (the right side needed only one strip of aluminum can at the back to flush it with the saw table).

I'm waiting on the T-track to come, I'll post pictures when it's installed to both sides.