Will Build a Moving Gantry ROUTER-comments appreciated.

[CNCfun&games]

Will design & build a Moving Gantry Router while I’m waiting for parts on several other Projects I’ve started.
I’ve calculated the travel should be about 54” x 44” x 6’’, because I have Thomson rods & ball bushings on hand which dictate those dimensions.
The Frame will be constructed of Rectangular steel tubing & the Gantry will be made from 6061 Aluminum plate.

I will include Drawings & calculations & welcome comments & suggestions!

Next week I will start machining the raw material and will post photo’s to record my progress!

W.Smith

[bgolash]

Hi
I used Thomson round rails on my machine. They are not as precise as the square rails ie THK. When I was designing my machine I asked the Thomson engineer what is the recommended spacing for the guide block. The answer was extreme. If the width of the machine was 20 inches that was the needed spacing to minimize racking. I didn`t follow the recommendation because I didn`t want to lose the extra travel on the X axis. Mine was a 13 inch spacing.
I do get a small amount of racking. My machine is 36 x 60

[CNCfun&games]

Bgolash:
Thanks for your input on your Thomson rail & ball bushing configuration.

I think I can minimize the problems you describe by driving the X axis with a Master/Slave orientation using 2 Racks located on the Steel Square tubes that support the ¾” dia Rails.

My Y axis rails are ¾” x 48” lg OPN’s. The X rails are ¾” x 60” OPN’s.

The Y axis is well under way. The rails are alligned to ea. other with 2 precision machined & reamed End Caps. Then assembled on a 2” x 4” Square tube slotted on the rear side to mount the Z axis and further isolate the 5/8-5 ball screw from contaminants generated by the router.

Enclosed are photo’s of tube machining.

W. Smith

[CNCfun&games]

“Y’ axis Parts in work!

After machining the Tube, material was prepared to use for the precision End caps.

The end caps were stacked, drilled and pinned with precision dowels.
All matching holes were then drilled and reamed for the .750 dia. Thomson Case60 Rods.
The center holes were drilled and bored for the bearing pockets, to support the Ball Lead Screw.

Next the rods will be joined to the end caps and located on the tube to check for fit.
Hopefully this should result in a strong, moderately light assembly.

W. Smith

[ZipSnipe]

Whoa whoa whoa there Speedy!!! What happened to your other build ,with the cast iron?

[harryn]

Nice work - It sure is convenient to have mill access to build a wood router.

[CNCfun&games]

ZipSnipe: What are you doing over here in the Woodworking Forums?
Guess I should ask myself the same question!
Take a look at post #57 over in my neighborhood.

Harryn: I have a Boss 4 & a 2J. I love the “Mighty Bridgeports”

Joining the 2” x 4” tube to the End Caps and OPN Rails is
documented here!.

W. Smith

[CNCfun&games]

Before installing the “Y” endcaps I assembled the basic frame to check my progress to date.
The frame is far from finished and lacks the structural integrity necessary to support the table
properly.

The “Z “ axis mounting plate & rails are shown as partially completed, but will be described in detail after the “Y” Axis is completed.

The electronics enclosure was designed & fabricated & will also be assembled when parts are delivered.

W. Smith

[CNCfun&games]

This Time I will begin machining the plates to support the “Y” axis bearing blocks.
They will form a structure which will allow the lead screw to be hidden in the main Tube. Normally the structure would form a C section. The Top & bottom plates supporting the blocks & the front plate mounting the “Z” axis & the Ball Screw Nut.
By adding a rear plate the lead screw nut can be attached to the back side of the tube, completely isolating the slot in the tube from chaff .

The plates are notched so that screws can be placed horizontally & vertically
to keep the joints from parallelogramming under load.

Here Goes!…….W. Smith

[CNCfun&games]

The Y-Z mounting block was finish machined & assembled.
The next step will be to machine the Thomson Ball lead screw stock to size,
install the bearing blocks and ckeck the Y axis for “Smooth Running”.

If this goes well then machining the X axis end plates should complete the
X-Y components for the moving Gantry. I’ll install Thomson double Ball nuts on the Y Axis screw. I used this configuration on a Bridge Mill Design several years ago and it’s worked flawlessly.
At $22. Per Ball nut it’s good insurance!

W. Smith

[widgitmaster]

Looks like a solid design, nice to see you making all the parts yourself too!
Widgit

[CNCfun&games]

WIDGIT: Enjoy your threads….Keep up the good work!!

Assembled the Y axis and the ball Bushings to the Mounting block.
The assembly as pictured weighs 33 lbs. The Mtg . Block slides
very smoothly on the Y axis Rails. So far…. So Good!

Next I’ll fabricate the X axis mounting plates and end caps, tram the X axis rails,
and check the gantry for precision movement.

I’ve decided to increase the X mtg. Frame from 2” x 2” to 2” x 4” to obtain more
Surface area to mount the .5” x.5” - 20 pitch Racks.