Gantry/carriage assembly

[goplumcrazy]

I anyone familiar with these assemblies? Starting my table build research. All advice is welcome.

[robertspark]

Yes my table is similar to that what do you want to know

[acourtjester]

http://www.youtube.com/watch?v=leWjHZe_rcc

[goplumcrazy]

It seems so easy to use brackets that roll on square tubing. I'm just scratching my head why so many table builds I see are so elaborate. I am just starting my build and trying to decide how intricate I will go. What are the downside to just plane ole roller bearings mounted with an eccentric? Another think I have been wondering. Some of the racks I've seen have no mounting bolts through them. Are they welded in place? Epoxy?

[robertspark]

To some extent.... Simplicity of using hiwin / THC rails... I mean think about it... It is constrained in two planes already.... And it's manufactured to close tolerance....

Cold rolled steel tube is not precision... Skate board bearings made in china are not precision.... But they are cheap... At the end of the day my view is .... It is plasma and CNC is a damn sight easier than hand cutting or grinding to size....

I don't use rack sorry.... I use htd 5mm belts 25mm width, steel wire lined.... Another way to skin that same cat... But it is only a 5'x5' table.... If I went 10' I'd switch to rack.... No belt slop or flap (they do have custom springs and are very taught)
... I'd probably spot welding the rack to the rail..... (Tig/mig) can always be ground off later with an angle grinder or just replace the rails with new when needing new racks....

[robertspark]

https://youtu.be/Lv1Mf4BrHKA

https://youtu.be/v8yKJyJICxw

[acourtjester]

Ok here is my video
https://www.youtube.com/watch?v=fErYc7W ... wq0KTKpuRw
this one using a drag knife to cut sign vinyl, If the table did not track the ends will not meet
https://www.youtube.com/watch?v=gn1Xh9P ... e=youtu.be

[WyoGreen]

GoPlumCrazy,

My racks are secured to the table with 3M VHB tape. It's the same stuff they use to stick trim on cars nowdays.

Steve

[djreiswig]

jester

I love watching that Amazing Grace cut. It doesn't look like much until it does the outline and then.
BAM!!

[acourtjester]

Thanks I enjoy watching the results too.

[tothwelding]

I have built a 4x5 table using these carriages same as the pic. My table runs great. I have made a few changes like adding some 1x1 alum bar to extend my gantry back further. My gear rack is welded to the square tube instead of the 3m tape