Questions regarding 5X8 table with indexer help needed

[myxpykalix]

I have ordered a 5'wX8'L shopbot prt alpha and since they don't have a kit for a table with a recessed indexer I am attempting to have a table made. Since all of this is new to me I am very unclear on issues or clearances I need to be aware of when talking to the welder about specific dimensions I need to be aware of.

For example on the table width of 5' if I have the indexer mounted below the table bed height and want to make architectural columns 12" wide what would be the width of the "valley" (the square U shape below the surface of the table)?
This design, if any of you are familar with Scott Cox's table and many others is what i'm aiming for. Also what is the router travel distance on the 5' axis, how close to the rails will it go (trying to determine if it will carve on a column the full width)? I hope i explained myself correctly...Thank you!

[hines]

I think Wayne Locke's setup is one of the most creative I have seen

http://www.talkshopbot.com/forum/messages/27/8747.html?1128196538#POST26548

[patricktoomey]

If you get the 12" Z option and drop your table top you can mount the indexer on the side rails of the table and still turn 12" columns without having to resort to a channel in the table. I have mine mounted on my side rails now with a 6"Z and I can turn 6" columns. I'm upgrading to the 12" Z and dropping my table 8" so I'll be able to turn 12" pieces. I'm dropping 8" because I'm switching out my wood base and plenum boards to a granite base with a Corian plenum on top. Using this configuration is necessary for me with only a 4x8 table. Doing a drop channel would screw up my 4x8 cutting. I can see where with a 5' table you could get away with it but it seems like you could do it easier by going with the side rail mounting option.

[myxpykalix]

Excuse my ignorance, but i'm confused by your description. I can't seem to find info on the shopbot site for the 12" Z option, so my intuition tells me that the carriage is mounted 6" higher relative to the table and plunges lower but now regarding the 6" C channel that the rails mount to, does the indexer mount there?

[scottcox]

Jack,

Here's a layout of my table to show the Y, Z and indexer travels. My 10' X axis is actually 125.5", my Y is 61.5" and my Z is about 8".

I have a 12" indexer shimmed so it sits even with my spoilboard edge. I can get to just past half a 16" diameter x 10 foot long workpiece. I can also move the indexer over and get a 10" log fully under the bit.


8676

[wayneo]

Jack,
When I ordered my machine I ordered with the 12" Z option. They have up to 24" option, but do not recommend it for much but cutting soft material as there is too much leverage on the Z when cutting in the X-Y plane.

I ordered the SB table (with the 12" Z option). They shipped the table with two "C" channels for each side (one on top of the other. Overall table height is the same, but table platform height is dropped down about 6". This gives a nice flat area on the inside of the 2 channels to mount the Indexer (sideways along the X axis).

I then built a raised platform out of 4'x8'x3/4" birch ply and straight KD 2x4's. I use this to cut my flat projects. Reason for doing this is to position the router closer to the traditional 6" cutting area. That way the leverage against the Z is not so great as it would be at 12".

I have since cut off 12" of my raised platform (along the X axis) and made it so I can re-install it very easily if I need a 4'x8' cutting platform. This gives me quite a bit of extra room along the X-axis and I plan to re-mount my Indexer in the normal upright position (instead of sideways). I also plan on mounting it on a long heavy duty plank so that I can extend the headstock and the tailstock beyond the normal 8' cutting range. This will allow a full 8'x14" piece to be cut on the Indexer.

Building the table this way (the way I have) makes it much more rigid and less flexing. It is probably cheaper than making all the dog-legs in the cross support pieces and makes for a more usefull table.

Just ask SB about the 12" option and the table modifications with the double "C" channels.

Best of Luck!

Wayneo

[djmcnutt]

Jack,

I have only had my machine for a few weeks and it's not up and running 100%. But I bought a 5' X 8' with the standard Z. I had a table built locally which is very simler to Scott's. I used the ShopBot plans for the 4' X 8' for the length and the 5' X 10' plans for the cross arms and designed my own center crosses. The table is all together and it looks like it will work very well. If you want some pictures and my plans just email me and I would be glad to send them to you. Good Luck...

[myxpykalix]

David,
Yes please send me any pictures/files/info you have!! (sent you a PM, couldn't find your email address)

Scott,
I have been talking to the welder using your plans (thank you!) However your picture you posted here has me a bit confused. My table is a 5'x8' but the overall width (according to SB) is 76.5". I understand the arrangement of the carriage and router limits your travel but I don't know what those deminsions are, to be able to figure out how wide my indexer "valley"(?) should be. They recommended 12" but i think it needs to be wider. In your drawing yours is 17.5" wide and this brings up another question. You have 3 round deminsions of 10",12",16" represented for different size columns you might turn. They seem to be in different positions laterally, does that mean you somehow move your indexer laterally to accomodate the different sizes? I hope i explained that correctly? Thanks!

[scottcox]

Jack,

The 76.5" width (without the x-rails)is correct for the 5 foot y-axis.

I positioned my indexer so that my router bit can reach over the highest point of my (roundish) workpiece (up to 16 inches). But I can move it over so that my bit will reach entirely across a 10 inch diameter workpiece.


8677

Also realize that your Y-axis travel stops "about" 6 inches from the inside of the side channels. To ensure that you can get your bit over the centerline of your indexer, you should be no closer than that 6 inches from the inside edge.

Note that even with my wider channel, I can still get 4 foot wide sheets of ply on the table.

Hope this helps.

Scott

[myxpykalix]

yes that makes sense and helps, now i need to run to the welder and make the change on the plans as i changed it to 12" wide, but your deminsions make sense....Thanks!!