[TommyM]

I'll be getting parts for a PRO108x48 machine next week and am thinking about how to integrate t-tracks without losing too much z axis capability. See the attached sketch. I'm new to CNC and AVID equipment. I don't know what I don't know.... any issues with this concept? I plan on using 48" long Orange Aluminum T-Track screwed into the plywood inserts. I was thinking of putting the top of the T-Track about 0.010" below the surrounding MDF so I could mill off the top MDF spoil boards when they needed replacement without hitting the t-tracks. Any advantage in going with 1/2" spoil boards (top layer)?

The spec's indicate 8" of Z axis capacity. Where is this referenced from? The face of the aluminum extrusions?

[GigaWatt]

I have a similar spoilboard setup on my Pro 4824. I wouldn't use screws as they pull loose undered repeated heavy clamping. I used bolts on mine and the mdf sb has a rabbit that overlaps the t track.

[TommyM]

Good idea on thru bolts/machine screws and nuts on the T-tracks.

[Kosh]

So... just got my expansion kit to take my 4x2 to a 4x8 capacity, and going through the mental experiment of how to change out my clamping to handle full sheets of plywood. I don't yet have a feeling for how much room on the sides there is for clamping from t-tracks (which is what I do now). Currently I have a 1" thick spoil board made of glued up 1/2 inch pieces of MDF, which I then mount to the 8020 cross members, then I have a Rocker bit that use to cut t-track slots into it. I also CNC holes for perf dogs on a grid in between the t-tracks. See attached picture. The problem is, when it's too "spoiled", I have to remake the entire spoiler board.

I think what I will do this time is mount t-tracks (Rocker probably) directly across the 8020 cross braces, and also probably double up the number from the standard Avid build. They will be secured with countersunk bolts into roll in t-nuts. Then I will do the same to strips of MDF that will also bolt into the 8020 slots, but in between the t-tracks. That way, I can replace individual pieces that are too spoiled, and then just resurface to the same height as the others.

The additional cross members will minimize the span of the MDF and reduce the chance for it to warp out of flat. This will work for most of my guitar building vacuum jigs, but then I think I will be adding on a removable vacuum table (or maybe smaller multiple ones) to handle the large sheets. similar to what they did here for their combo table, except where theirs is a vacuum table with removable t-track table, mine will be a t-track table with removable vacuum. That insures me the maximum z-axis height for cutting guitar neck heels when the fixture is in place.





https://youtu.be/5hKCy8TkUJo?list=FL...sM7scZc6R8dQmA

[philba]

One point about T-Tracks - they aren't all the same. I've had problems with Rockler "Universal" T-Tracks. It uses a "standard" profile and does not take standard 1/4" hex nuts/bolt heads. Look at the profile and you will see what I mean. I believe their goal is to lock you into fasteners from their various kits which is why the T-Tracks seem to always be on sale. It's ok if you are willing to be locked in, I guess. I've found some toilet flange bolts fit ok. But, IMO, having the flexibility to use 1/4" bolts is worth going elsewhere for T-Track. The Rockler jigs and such will still work. I get my T-Tracks from Peachtree and they are cheaper than Rockler, too. The mini T-Track is only 3/8" high and works well with 1/2" MDF like in the video from Legacy.

[Kosh]

One point about T-Tracks - they aren't all the same. I've had problems with Rockler "Universal" T-Tracks. It uses a "standard" profile and does not take standard 1/4" hex nuts/bolt heads. Look at the profile and you will see what I mean. I believe their goal is to lock you into fasteners from their various kits which is why the T-Tracks seem to always be on sale. It's ok if you are willing to be locked in, I guess. I've found some toilet flange bolts fit ok. But, IMO, having the flexibility to use 1/4" bolts is worth going elsewhere for T-Track. The Rockler jigs and such will still work. I get my T-Tracks from Peachtree and they are cheaper than Rockler, too. The mini T-Track is only 3/8" high and works well with 1/2" MDF like in the video from Legacy.

Yeah, I thought those were meant to handle both types. The MDF slots I cut right now are for the rocker t-bolts, so I am already sort of committed to those.

I was going to increase cross members to have 8" spacing in between so I use the existing countersunk wholes int eh t-track for securing, but now I'm wondering if putting clamps in the unspotted sections of the t-track would actually cause them to pull up/distort. Need to think through that.

[minsk]

love the rabbit idea...great idea