[mhiggins]

I have been working on a new gantry for my 2006 which incorporates design elements from Joe's 4x4 as well as mods inspired by other DIY machines, commercial units and some of my own ideas. I will try to give credit to those whose concepts inspired my design but sometimes I forget where I found them. I'll do my best since I don't want to take credit for anyone's work.



I know my existing machine doesn't look exactly like the traditional Joe's 2006. If you would like to know why, here is a link to my original machine build.

http://www.cnczone.com/forums/showth...ghtly+modified

[mhiggins]

[mhiggins]

Some info on the 4th axis build.

[mhiggins]

More an the 4th axis.

[DayneInfo]

HURRY...I want to see more

[calgrdnr]

Thanks Mike , I have been think about modding my z and y also. I will be watching with great interest. also would like indexer


Kent

[mhiggins]

Here is a video showing my cable carrier. I modified drawings I found on this thread to create the toolpath.

http://www.cnczone.com/forums/showth...=cable+carrier

[mhiggins]

I found the inspiration for the carriage on this thread.

http://www.cnczone.com/forums/showth...uter+enclosure

I changed the design by leaving two inches between the 1030 extrusions to make room for the leadscrew. The plates on top and bottom were made with a hacksaw and a file out of some scrap machine parts I had on hand and are 3/8" thick.

I used 1/4" plate on the front and back. Two pieces on the front to allow for the leadnut to pass between. Two pieces on the back to allow for additional adjustment between the upper and lower v-groove bearings. The bolts that mount the bearings pass through the plates and thread into nuts in the extrusion.

EDIT: I almost forgot to thank Joe for his 4x4 design which is the inspiration for the gantry and v-groove bearings. The last pic sort of tells it all.

[mhiggins]

I used 3/4" aluminum plate for the Z-axis. The leadnut is mounted to another piece I sawed out of scrap extrusion and bolted to the back of the 3/4" plate. The center pic shows how I used a bushing to line up and mark the bracket with a transfer punch. The bushing was filed down on the drill press to fit the hole in the upper bracket of the carriage.

In the first pic you can see there is a bearing block on the top and bottom of the upper plate. The two bearings are loaded against each other and there is no support for the leadscrew at the bottom it just free floats. I used a dumpster threaded clamp on the top and a plain steel clamp on the bottom.

[lumberjack_jeff]

Very nice cable chain. What dimensions did you use?

[FandZ]

I like it all. Nice work! I'm going to have to make some of that energy chain. I recently enclosed my wires into a wire shield like you showed in your 1st video. I just couldn't figure out why I couldn't make it bend in the air like yours did...lol I feel like an idiot now.

[mhiggins]

The first pic shows the bracket for the leadnut and the second shows a gusset that I added just for the heck of it. I'm sure it would have been plenty stong without it.

In the last pic you can't actually see the leadnut but you can see theends of the machine screws that hold it on. You will also notice that I drilled a 5/16" hole just below the leadscrew for a 1/4" rod to pass through. I made HDPE support followers for the leadscrew. I threaded the ends of some harware store steel rod to screw into the followers and used jamb nuts to keep them tight and indexed. You can see the jamb nut in the last pic.

All I had was 3/4" HDPE so I cut a 1" wide piece for the bottom and cut a 1/4" deep tenon to ride in the slot on the extrusion. I used a 1/2" ball mill to cut the groove in the top and bolted the two pieces together with machine screws. The followers are captured between the extrusion and the leadscrew. The leadnut bracket will hit one of the followers and drag the whole assembly with it allowing the other follower to support the leadscrew. The followers are short enough that they don't reduce the axis travel.

EDIT: I added a pic that shows the follower a little better.

[judleroy]

I love the way you did your cable carrier. Would you be willing to post a dxf file for us to use. Thanks Judleroy

[mhiggins]

Very nice cable chain. What dimensions did you use?

Several people posted drawings on the cable carrier thread and I don't recall which one I based mine on. Mine are about 1.36" tall, 2.53" wide, and 1.93" to the centers where they pivot.

It has been a while but I think I just scaled up someones elses drawing then modified it to be cut start to finish with a 3/16" end mill. I added the dovetail feature thinking I would glue the bottoms on then be able to flex them enough to slip out the tops. I originally drew the dovetail tenons 1/8" long with this in mind. After cutting some test parts I realized that the 1/8" PVC was not going to flex at all over that short length. I changed the tenons to 1/4" and still glued the bottoms on with CA then just snaked the cables through it. The chain turned out to be the perfect size as I was able to feed the molded plug on my router power cord through it nicely.

I did end up doing some hand work on the links. Turns out I didn't allow enough clearance for them to run smoothly so there ended up being some disc and spindle sanding. In the end it works great.

Here are the MDF prototypes.

[mhiggins]

I love the way you did your cable carrier. Would you be willing to post a dxf file for us to use. Thanks Judleroy

I had to do a fair amount of hand work to get everything running smooth. I think it is because my prototypes were cut in MDF which didn't challenge the 3/16" cutter so they fit up pretty good. When I ran the same program in PVC it must have flexed the cutter or Z-axis (or both) because the fit was much tighter.

I would hate to post a drawing that doesn't quite work and make my friends have to sand and file like I did. If I get some time I will try to improve the drawings so they will work better for others than they did for me. If I can get them fixed up I will post here as well as the thread where I got the original drawings.

In the mean time you should check out the cable carrier thread. You may see one you like better.

http://www.cnczone.com/forums/showth...=cable+carrier

[mhiggins]

For those interested in the fourth axis, here are a few still images for reference.

Obviously I won't be cutting anything with this just sitting on sawhorses but I wanted to get an idea of where it would need to be positioned. I picked up some plywood after work tonight for the roller cabinet/stand. I don't know if I will get started on it this weekend or not. With Thanksgiving next week, it may be a while before I get to it.

I will be using the same casters that I used on the router stand and I bought some turnbuckles to pull the two cabinets together to keep everything rigid when I am cutting.

[FandZ]

I made HDPE support followers for the leadscrew.

I'm mighty impressed with that. I've thought of making a floater of sorts to prohibit a lead screw from whipping.

Is one of the reasons for your wide gantry beam to allow room for the followers movement? I know in the video you talked about the sides being used to hold tools but I'd imagine the follower wouldn't work out if they didn't have the extra room.

[FandZ]

Sorry to keep asking questions, but your not worried about racking when you are useing your 4th axis?

[mhiggins]

I'm mighty impressed with that. I've thought of making a floater of sorts to prohibit a lead screw from whipping.

Is one of the reasons for your wide gantry beam to allow room for the followers movement? I know in the video you talked about the sides being used to hold tools but I'd imagine the follower wouldn't work out if they didn't have the extra room.

I don't have a good picture that shows the back of the carriage but the followers are short enough that they tuck between the leadnut bracket and the brackets at the ends of the gantry without reducing the carriage travel.

I made the gantry long for the 4th axis on one side and a tool rack for an ATC on the other (future project). I think the extrusion is 73.5-inches long. I bought a six-foot lead screw and ended up using it without cutting the length. I believe the actual carriage travel is right about 60-inches.

I originally took these pictures to show how far the cutter would go outside the gantry but if you notice, the carriage stops right up against the motor brackets on either end of the gantry.

[mhiggins]

Sorry to keep asking questions, but your not worried about racking when you are useing your 4th axis?

I'm worried about all kinds of things but I'm optimistic.

If I get some racking I guess I will have to take light cuts while I work on another upgrade to correct that.