Good bracing would be something like this:

Snapper....hmmm (old college humor for you in the cheap seats)

Matthew,
I did consider it...then forgot everything I was doing because I am do darn busy to think clearly lately. You do have one good point to rotate the motor. I could keep the sides intact and still add the "kickers" Gerald suggested. All these ideas and little time this week to do anything about it!
Everyone Thank Alan for doing the quick sketchup model. :)

Sean,
Any new developments on the new spider design? How did your laser cutout come out? :)

...nothing new. Still trying to push the 3" of water out of my shop at the moment. I really don't like hurricane season.

Sean,
Hope your water problem goes away soon! :)

status ?
 

Hi,
I am new to the forum and I am also interested in cutting foam only and a long z axis.

We are still waiting anxiously for Seans update on the Super Spider long Z. :)

Heath.
Should be this week. Trying to fit the MM upgrades in the the production schedule, Santa and other projects (okay - honey do list). :)

Banter on domestics moved here.

. . . .

This may be off topic, but if two Z carriers were used, what would be an appropriate way to hook up dust hoses? Over the side of the car around the Y axis frame?

. . . . . .

Jack, dust hoses for twin Z's are a major headache - they have to fight for space with the y-motor or with the y-cable chain. (They cannot pass outside the y-car. between the gantry tubes without reducing the y-travel)

Extending Z
 

I have never been really happy with the Z axis. For flat work it is great but most of my work is in lathe mode and ocasionaly it can be driven down a tooth or 2 on the rack. Think of a 14" square by 10' piece of fir running at 100 RPM and being cut slightly off TDC. Not what Gerald designed for. Also had problems with the A axis when running at 4.5:1 but since I installed the 10:1 gear box it is doing fine. I am working on a Z with 10" of travel using a lead screw with 10 TPI Acme thread. It is being prototyped from plywood and will post prictures once I get it running.

Current discussion at ShopBot forum:
http://www.talkshopbot.com/forum/mes...312/37276.html

Sean,
Any update on the super spider project? Was wondering if you got it together yet? :)

getting closer to reality
 

Attachment 3489

Attachment 3490

Closer....maybe next week I'll be done with upgrades

That's got my attention!

Sean,
Wow that looks interesting, cant wait to see the end results! :) Sorry for the push. :o I know others are intereseted, as I had one cut for someone on the forum. :eek:

Sean,

Wow, I like it. When you get it done I will be at the shop.

Sweet!

How much Z-travel are you planning?

Regards,
John

Usable travel is about 36". Mechanically able to stroke 42", but we will see what I get actually.

I love it!:) Really looking forward to your progress.

Looks like that aluminium (UK spelling) I-Beam should be stiff enough. Are you beefing up the Y-Car/Gantry in some way to keep them from tilting?

Regards,
John

The I-Beam is stiff for bending, but it is quite flexible for twisting. If the router had to go on the face furthest from the V-cap rails, the cutter would be quite far offset from the rails. Looking down on the table from the top, cutting force in the y-direction would cause the I-Beam to twist clock/anti-clockwise. Unless you can get the cutter placed between the v-rails (still looking from top), the torsion becomes an issue. Generally, a box-section (hollow profile) is the most desirable for long overhung z-axes.

I see your point. So are you thinking of something more like the extruded box-beam this fellow uses?

Regards,
John

Actually,
When fabrication is complete, it will look very similar to Geralds post #33 in this thread.
The web and outside flange will be removed to allow for the router/spindle to be in the same position as the original z-slide. Thus, to reduce the twisting both of you are very keen to notice. Instead of manufacturing a long back bone, I just happened to have an I-beam the right dimensions.
Sean

Sean, I knew you had thought that one through already. My last post was for the wider audience who might have been tempted to go and buy some I-beam. Yup, first use what you already got! :)

Todays fun!
Attachment 3538

Today I was able to see the modifications that Sean is making to his machine and I am eager to see the new Z and Indexer in action.

The plot thickens! :)

Notice that the traditional wrong_way_bending of the the 2 small tabs in the spider have reared their head again, but you are surely not using both of them.

...yep. Noticed it. Not using either of them so I really didn't care. Keen eye Gerald!
Did you notice the extended "leg" on the diagonal. I had the laser cutter leave an arm on each side so the back gauge on the brake press would ensure a parallel bend without trying to "visual sight" the bend.

Smart thinking on the gauge tabs for the back-stop - I thought they were for the red braces in post #41. What have you got under your V-rollers? Look a little small, the roller may "wobble" a bit (cantilever overhung from the spider).

Machine drill index pin collars the same diameter as the bearing race. Temporary.

Vibration.
 

Hi Sean,

Do you anticipate any vibration on the extended Z arm passed on by the router? I know that aluminum has a tendency to vibration. I'm looking to build a similar machine with an extended Z and your solution seems to be the simplest.

My try
 

Because of the laterial and vertical force involved the rack and pinion on the Z gets lost. I replaced it with a lead screw I have 10" of travel with the Z plate between all V rollers and up to 15" if I go past the top ones. Will have it installed and running next week.

bbq ready to start cutting
 

Today's installation.
Z-slide, balancer, and cable work well. Next stop....4th axis cutting!

Attachment 3980

Attachment 3981

Serious Z
 

Nowthat is a real serious extended Z! You gota show the whole machine in one picture amd working.

Uau :)

Sean,
I noticed in one of your pictures that the lowest set of rollers is now missing?
Is this a mod? Just curious, or perhaps the picture is of a non complete unit?
Looks awesome though! :)

Heath,
I had a problem with the hole on the that side of the slide.
I needed to get cutting, so I left 1 bearing off. The threads were tapped slightly not square and was causing the bearing to not seat properly, so I left it off.
Thanks for noticing! :p

Good work Sean!

I still think it would be good to bridge the gap. You could even go as far as the second router bracket . . .

...Planned, just not installed yet!
That's todays metal working challenge. For the life of me I couldn't wrap my head around that electrical cord exit, so I just said I will cut something to fit in the field.

Can't you rotate the router 90 degrees so the cord will be on the right side???