How will you attach the steel box section to the side plates? Are you going to build custom ones? And what about the rails?
One thing that I liked about the 40x40 V-Slot (or Misumi or similar) is that once you figure out the side plates mounting, there’s no more drilling.
This sounds more like an original build, rather than an X-Carve upgrade. Very interesting and very ambitious.
I have to say though, I do not envy you for having to drill and hand tap 80 holes 
A picture is worth a thousand words. Thanks.
Ok, I can picture it now. But, oh boy, welding and drilling (and freaking-hand-tapping 80 holes! ). It seems to me too much pain for no significant gain compared to the alu 40x40. It also seems to me that you have plenty of free time (moi, I have two toddlers). If you are up to the challenge, go for it, by all means 
Now, this, I would love to see!
Awesome yeah the piece from open builds where the v wheels was the only part i was lost on i may go this route as i trued the bolts down theough the two and i did not like the way it came out for me thanks for the info !
Honestly, if you plan to go that large, I’d just go right up to using a midsize router as a spindle, or something larger and better suited to CNC operation. Also, you’re probably going to want more powerful steppers, and probably much larger, stronger belting or a toothed rail, etc.
Sounds like a darn good plan to me. Angus!
Great modification. Which eccentric spacers are you using? I see four options at the Openbuilds web page.
thanks.
I used the “1/4” - Full Size". The “6mm - Full Size” will work too and so will the 25195-01 from Inventables.
thanks for your reply regarding the eccentric spacers. the title of your post (mod pack 1) leads me to think you have more ideas in the works. will there be a mod pack 2?
No problem.
Well, I keep noting down ideas for further additions, so a mod pack 2 is indeed likely in the future. Some will probably see the light, some will not. Most likely to be implemented:
Stay tuned
Adding a second X motor will double the torque ? (it’s just an idea running in my head…)
Not adding… I was talking about replacing the original X-axis motor with a higher torque one, to go
from
1x 140oz.in on X and 2x 140oz.in on Y
to
1x 262oz.in on X and 2x 140oz.in on Y
yes i have understand, but i was thinking about an other idea, just adding a second motor on the X-axis
a cheaper way to have more torque, and equal torque to y-axis (juste the price of one motor)
but i’m not sure how to calculate toques so i dont know if adding a second motor will double the torque
Well…
case 1: swap out the stock 140oz.in X axis motor with a 262oz.in one
difficulty: none
cost: 50$ and 10 minutes
case 2: add a secondary 140oz.in X axis motor
difficulty: very high
This is both more expensive and mission impossible (and, honestly, not a good design). Why would you even wanna try this?
indeed,
I have not thought that far
stupid ideas in the morning …
all my excuses
No worries. We are here to exchange ideas, practical or less, which in turn they may trigger new ones.
But, does the y axis actually have twice the torque of the x? they pair of motors are driven by the current of the one stepper driver on the g shield. Assuming you are running a basically stock electronics setup…
There are two distinct issues here.
(a) Can you sync them? As long as you do not introduce any factor that significantly affects the syncing (physical or electronic) of the two motors, their aggregate torque at any given current will theoretically double.
(b) Can you drive them? You have two 2.8A motors and either one 4A driver for each (X-Controller) or one 1.5A driver for both (gShield). Therefore the X-Controller can drive them to full potential, the gShield can take advantage of roughly a quarter of their potential .
Another thing to consider is that @1/8 microstepping (which is the default for the Y axis), the torque drops at ~20% of the nominal. So we are not really talking about 140oz.in or 260oz.in, but rather about 28oz.in or 52oz.in .
Sounds like a good case for a Gecko G540. 3.5A per drive (4 drives). Microstep morphing which means that at higher speeds, there’s no micro-stepping so no loss of torque
