new biuld 24 x 48

[dertsap]

well i was going to go 4 x 6 but decided to stick to the size of my original build, i designed my gantry in a way that once the spindle is on it will be sitting centered to the base of the gantry , the last one hung out past it ,which i think caused some problems when pushing a fair bit of torque against it , y and z i am using drill rod and bronze bushings which slide pretty freely , the x i am still not 100% sure of the direction i want to go ,but here are some picks of the system partially together

[Bowman]

I think your wise to design the gantry so that the spindle is centered over the the base. When you think about the weight of the gantry top and the forces of accel and decel going back and forth with the moment being 12-20" away from your contact points is going to make the top want to swing with each direction change. Looks like you have a good start going. I will be starting a build log soon and that is a definete consideration in my design. Even using bearing blocks and precision rail the weight of the gantry at that moment is a factor and I really don't want it offset far from the centerline.

[dertsap]

ive built and butchered few gantry designs experimenting with lead screws and slides and such , i think i found what i like and i beleave the balancing act should well work to my benifit , and if it works well enough it will be incorporated into my design for a 4 x 6 or 4 x 8 table which i hope to do by next year , this table will be used to built the parts for it , and once its complete i will pass this one off to my two boys ,hopefully by then i can have them understanding fractions and decimals as a kid i hated math so i know what their going thru

[Bowman]

I thought of a good example of weight and moment that demonstrates how the weight offset shifts the point of pressure exerted. I made one of these in high school to show a science teacher and it baffled him and others as it would appear to defy the laws of gravity.

Here is a dxf file I made a quick drawing of the piece it can be made from a little piece of scrap wood. Just make the wedge and hang a belt from your pants in the slot centered and hanging towards the tip of the wedge. Place the tip of the wedge on a table or your fingertip and it will stick straight out. Simple demo of how the transfer of weight over a distance can be applied to one small location and depended on to support the entire weight.

[Bowman]

I forgot I have a dig cam now hehe so I had to go make one of these again myself. Took about 66 seconds I think anyway here are a few pics of the wedge. Your kids should find this interesting to show friends. Anything you can do to spark and keep interest in gaining knowledge is a good thing.

[dertsap]

BRILLIANT ! i didn t quite catch the concept from your earlier post so i went outside cut a piece of wood and tried it ( doing it the wrong way) , but i gotcha now , ive got to try that ,

[dertsap]

OK so call me an overgrown kid ,but the first thing i did was run back to my workshop to see it in action , but i do see how the weight distribution is as you said

[Bowman]

I think we are all overgrown kids here. Why do you think I had to go make one AGAIN Going out to dinner with the family for mothers day I will have to bring my highly engineered wedge to show my nephew. Just hope he doesn't want it as making another would be hard to do lol.. I will be selling plans for the wedge R2 in the near future.

[dertsap]

if your showing the nephew i d say its as good as gone , and are you sure you can t put the r2 wedge open source ??? but then i suppose research and develpment is never cheap .

thanks dude

[jdholbrook]

Had something very similar when I was a kid only it was shaped like a "7".
Lay the belt in the crook of the 7 and balance it on your finger at the base as a sort of laying down 7.
Pretty cool.

[dertsap]

got er pretty much together everything is quite smooth on all axis , next is to build a table to put it onto and build an enclosure around it ,and connect a dust collector to it , i learned on the last setup that i'm blowing dust out of my nose for a few days and hacking up mdf , so the enclosure is a must , also is a pic of what my one track mind has reduced my once tidy workshop to , suppose next step should be to clean this up

[HayTay]

Yo, Derstap!

Ummmmm... Isn't your Z-azis is gonna be kinda slow??? Just kidding!!!

Kudos on your second(?) build. Is the bed 24"x48" or is the cut size 24"x48", or both?

I'm currently using my JGRO table to cut out Joe's CNC model 2006 R-2 machine (definitely needs a cooler name). It's amazing how much more space a CNC machine capable of cutting a full 24"x48" sheet takes up. I may have to send a bunch of my extra stuff to "2muchstuff". Nah, as soon as I do I'll need it.

Again, congrats',

HayTay