The Hangover Part 3

[BillK]

This is my new Z carriage assembly, all aluminum, only reused the back part. I carve over the edge of the table for box joints, dovetail joints, and bowl edges. This new set up allows me to change from standard carve to overhang mode in less than a minute without tools. I designed this with the Vectric software, and cut it out from one 6.5 x 24" piece of 1/2" Aluminum on a Tormach PCNC milling machine. The clamp for the colt is a real exact fit. The router clamp fits snugly between the two sides. The two clamps that hold the router clamp in place have a small strip that puts a lot of pressure on the router clamp face so no movement. All the parts are dado jointed together, then screwed together with tapped holes into the aluminum.

Real square, real solid.

I have a two inch overhang with this arrangement.

A back

B forward

Overhang

[BillK]

The old parts.

[studio-n]

that's an excellent design.

[EdThorne]

That's terrific! I wonder if I can do the same for my PC 892? Maybe it's too heavy. I have a colt with an aluminum extension but the setup time is quite long so I haven't even used it yet. I suppose that I will eventually.

[BillK]

Ed, how about a hybrid design? PC 892 in the normal position, Colt in the forward. Keep clamp attached to router, remove whichever is not in use.

[EdThorne]

Thank you Bill. I'll have to think about how to design it but the concept is interesting.

[BillK]

After using this for a few hours, I gotta say the aluminum is great for keeping the router cool. The original plastic is an insulator holding the heat in. Not great for the bearings. If you have a chance to convert at least your clamp to aluminum, do it. The heat sink effect is very beneficial.

[EdThorne]

Hi Bill,
Thank you for the suggestion. I converted to an aluminum clamp within weeks after buying my Mako Shark. The original plastic clamp allowed the router to slip and destroy my work and the tabletop. Sam made mine for me and I've never had a clamp issue since. Sam also made a clamp for me that allows a Colt router to extend over the edge of the tabletop. This is also aluminum. You're absolutely correct about the heat distribution. That's an added benefit.
Ed

[NewAgent45]

Bill,

Nice well designed upgraded Z carriage assembly. I have one concern which is an even bigger concern for the HD with the heaver router. Torque from the over hang. It is a known issue where the original HDPE gantry cross member plate is used. This is documented in some other posts on this forum including http://www.cncsharktalk.com/viewtopic.php?f=7&t=4264 which refers to the Black Diamond is a dressed-up HD. When I replaced the HDPE plate with the Aluminum plate I noticed and improvement in gantry sag and also Y direction flex. I believe your design would benefit from the Aluminum plate.

Just a suggestion here. Nice job!

...... Rod

[BillK]

Rod,

Thanks. My maching is the Shark Pro Plus, the first design with the aluminum table. The gantry has minimum aluminum re-inforcement. Adding aluminum to the back would have a minimal effect on my machine as the shafts for the X-axis are not the supported type.

Just used my machine in overhang mode, with my Bosch colt to do box joints on 4 inch tall box sides. No issues. My gantry sides are straight up and down, so its only about a 3.75 inch reach to get to hangover mode. I also ran successfully with all HDPE parts before. The issue was changeover time and the added benefits of the aluminum stiffness and heat sink properties.

Someday I may rebuild my machine with all supported shafts, but I have made tons of stuff with this machine and its deficiencies and have had little to complain about. The Shark has paid for itself a few times over.