Hints and Tips Wanter: Mobile Base for Extra Rails

[jackellis]

I recently purchased a set of BT3000 rails so I could easily cut larger panels without having to reconfigure the stock rails and accessory tables. Since I don't have enough space to keep the extra rails permanently attached, I want to mount them on a base I can more out of the way when I don't need the full rip capacity. I have T-nuts and studs on order from Jeff (thanks for the Father's Day Specials). Answers to the following questions, plus any othe hints and tips, would be most welcome:

1) Are there advantages to hanging the rails using the inside rail slot as opposed to having the rails sit atop a support that fastens to the bottom rail slot?

2) I'll need a way to support stock in between the extra rails. Has anyone simply used roller stands along with the commercially available wide table kit, or should I plan on building a table?

3)

[Tom Miller]

Keep in mind that you can always cut the rails, and leave some length of them permanently attached. You might find that an extra 18" will cover 90% of the cuts you make, for instance.

1) Are there advantages to hanging the rails using the inside rail slot as opposed to having the rails sit atop a support that fastens to the bottom rail slot?

Are you referring to the connection between main and extended rails, or how the extended section is supported? If the former, the kit provides for using both the inside slot AND the bottom slot. Some folks make their own connection hardware using Al angle that, again, uses both inside AND bottom slots. I'd recommend using both, as well.

If you're talking about supporting the rail, it can be done with either. And some designs support the rails indirectly by supporting the table section which is attached to the rails.

Regards,
Tom

[jackellis]

I have the connection hardware for hooking up two sets of rails. This is really about how to support the extension rails properly.

I've also seen posts that talk about hanging a support table from the rails, but without something to support the rails, I could see the saw tipping from a combination of a heavy table and stock. Supporting the rails is mainly a safety issue and I'm looking for a combination of ease, mobility and safety.

[JimD]

My table is in the articles section (Spruce and Sandeply) and has a different rail connection than normal. My rails, both the first rail that came with the saw and the extension rail, rest on a bracket screwed to the base. They are clamped to the bracket using a piece of 1/8 thick flat stock in the bottom slot and knobs with 1 inch studs that go through the bracket and into the flat stock. That leaves the inside slot to support the extension table which is clamped into position similarly. I leave my rails and extension table on all the time because I have space. It would be possible to slide it on and off, however, if you needed to. You need the base to be wide enough to support the first foot or so of the extension rail - at least the bracket part has to be that wide. It could still be only the foot or so wider than a stock BT3100 except for when you add the extension rails and table.

Jim

Jim

[jackellis]

Jim, your writeup and photos were very helpful. The most sensible way to do this is to have the rails rest on support and use a combination of studs with knobs and T-nuts in the rails to secure things. The supports will in turn be part of a mobile frame and the support table will be attached to the insides of the rails.

[JimD]

I'm glad you found the information helpful. I think t-nuts will work but I used the flat stock with tapped threads for a couple reasons instead. First, it helps align the rails to have a piece spanning the connection and filling most of the bottom slot of the rails. Second, I was worried that the t-nuts would move if I ever removed the stud from them and then I would have a mess trying to get them in the right place again. In terms of clamping things in position, the t-nuts would be at least as good.

If you have not tapped threads before I can see what that could be an issue. I had done it several times previously so it was not an issue for me. I used some cheap HF taps which worked fine. You can also get combination tap drill bit sets pretty inexpensively. The only real trick is to back the tap off every 30 to 90 degrees of rotation so that the chip breaks off. If you spin the tap in several turns into fairly hard material, you can get it stuck where you have no option but to break it. Periodically going backwards avoids that trap. I did this the wrong way once and ruined a head of my VW so now I remember what not to do.

Jim