Suspect it has to do with the speed control?:

Gerald and JR.
You are both correct.
I have 2 router heads. One is the 7518 model which is single speed (for foam) and the 7519 model which I use for wood, metal, etc. So, you both are correct. I will try both heads today and see if I can't make it work. i'll be honest and say I didn't spend to much time on it yet.

Z installed
 

I got the Z installed and rinnind and it looks great. With the Z all the way down ithe plate is still between all V rolers.

Nicely done Art.
Today I was able to rotate the router 180 degree's and have the cord exit the rear next to the slide. Final stiffener bracket is in the works.
I have to add "one more rotation" on the cable balancer tension spring and I think my slide will be dialed in for vertical travel.
I have a small challenge with my indexer at the moment, but I will address that later this week.

Hi Art

My project has a similar setup as yours, with a lighter (shorter) gantry and I am at the moment a bit worried about my gantry not being heavy enough and lifting out of the tracks.

Have you made any attempts on testing how much force you need to put on the router bit with the Z fully extended (down) until the whole gantry starts to flip (wheels start to lift)?


Ultimatelly I would like to be able to calculate the exact force needed to start lifting wheels out of the tracks, but at this moment it's probably still out of my knowledge base.

thanks,
Francis

Extended Z-slide summary
 

To All,
I have received a few emails lately on the performance and details on the slide extension I have modified for foam cutting.

In summary:

What is the Z-slide made of?
- W6" x 4.7#/ft Aluminum I - Beam
- custom z-spider
- BWC Vee Rail
- 8 - BWC #3 Rollers
- 1 35# constant force spring/cable balancer
- porter cable 3.5HP router
- 3dcutting.com 12" x 14mm round nose bit


Usable cutting distance
0 to -36" Z
0 to -12" Z you can cut all normal MM materials (ply, plastics, etc)
-12 to -36" you can cut foam upto about 22# density...I haven't tried more dense materials

In use for about 8 months with no issues.

Pictures for review:
Attachment 5762

Attachment 5763

Attachment 5764

Attachment 5765
DO NOT PAY attention to the small little bushings behind the VEE wheels, this was a temporary set up for alignment use only. Use the MM specified bushings

Attachment 5766

Cool Sean. I'm amazed at the innovation on this forum.