Looking for advice/concerns on new design

[hemsworthlad]

Hi stangtjk,

Nice result with MS, i think there warranty/repair service is great, they have come good with me in the past too.

Your machine looks cool, like it very much. Great renderings as well, only thing that i can see that you dont show is how are the 2 sides connected together.?

I can tell you from my build that the side to side movement from the mass of the Zaxis moving across the gantry can be felt in the base of the machine.
So any weakness will be highlighted sooner or later.
I you can i would run some sims with the forces in this direction.? . . . . Which by the way i think is a cool feature to have, wish i'd had it when i drew mine!!

Cheers
Dean.

[stangtjk]

You cant see it, but in that last render showing the mdf spoilboard there is a metal structure of angle iron underneath supporting the table and tying the two sides together. I'll probably add a piece of tubing across the front and back of the machine as well or at least gussets on each corner if I decide the tube will get in the way. I ran a simulation on the gantry uprights as if you were pushing on it from the side (I think thats what you were meaning?), with a 50lb load the deflection was .004". I'll do the same study for the base of the machine next. I don't know why I keep using 50lbs it just seemed reasonable for cutting through wood. If anyone has a better idea of how much radial load is acting on a tool cutting into wood let me know.

edit: The base showed a deflection of .002", adding the .004" from the uprights gives a total deflection perpendicular to the x-axis of .006" with a 100lb force (50lbs distributed to each side of the gantry). Looking at the numbers you posted on that other thread this seems reasonable, my machine looks to be about half the size and has twice the deflection, makes sense. I'm not a machinist so these small numbers aren't as easy for me to grasp, I have to put it into terms I can relate with so .01" is about half the size of a piece of lead from a .5mm lead pencil. If I can get my machine to perform within those tolerances I'd be tickled.

[DIYaholic]

stangtjk,
In your rush, out the door to the shop, remember to load ALL your neccessary tools, equipment and supplies. You may want to have a checklist of everything you MAY need. Just so you don't forget, a camera/camcorder is a must (of course, check the batteries). There are those of us here on the zone that must see pictures and video (machine p0rn).
On a more serious note, great job with the renders & simulations. Is the simultor able to simulate motion? It would be cool to see your machine in motion, even before it is "Built". I also hope some of the zone "experts" chime in regarding the actual forces involved, I'm sure others would also be curious.

Randy,

[stangtjk]

Solidworks has the ability to do motion simulations, however I don't. The way I have all the mates I can click and grab the router and move it around and see each axis moving together but when I tried to do a motion study it took forever to rebuild everything and some not so good stuff starting happening lol. I'm sure its because I didn't know what I was doing. I guess I could cheat and just record me dragging it around.

Edit: Ok I used FRAPS to take a video while dragging it around. Its going to take forever to upload but I'll share it when its done. I couldn't reliably drag all three axis at once without one going off the deep end so its just going to be 2 axis movement.

Edit: Finally uploaded, did this just for you Randy lol.

[stangtjk]

Not the greatest video but you get the idea.

[DIYaholic]

Thanks, I appreciate the effort.
You may even win a cinematic award, perhaps "Best Animated CNC" Oscar. I didn't even see any noticable deflection. lol

Randy,

[stangtjk]

I got my belts from polytech today. I think that pretty much does it for the parts I needed to order for the machine itself. I still need to pick up the little things like wiring, hardware, etc.

rcbamm, The belts mate up with the pulleys just fine, I don't believe there will be any noticeable backlash, and from my calculations the 12T pulleys wont have any problems handling the loads. I don't know what you're expecting out of your router but it looks like its going to work good enough for me.

Here is my stash so far. Hopefully this weekend it will start to look like a CNC machine and not just a heap of parts.

[hemsworthlad]

Nice Stash, at first i was trying to figure where the bearings near the pulleys fit into the equation then it dawned on me!!. . . . . For pulley shafts. . . Yes.?
Cant see any Caps or BR for PS or do you still need source them.?

I use a long belt to turn twin screws and dont get any backlash that i can detect, so long as belts are tensioned correct then you wont have probs.
I,m just about to make a very similar but smaller machine as yours for my son and dont have any quarms over using belts, infact i would take a bet that it,s just as good as my ballscrew'd machine.?

[Zygoat]

hay stangtjk. i am looking pretty hard at the im804 that i found on e bay. ( i think it was you who recommended it.) i am still a couple weeks out, so i would really like to hear how these work for you. (since they are basically the same thing, the 804 is just higher power.)

also i may be needing your help when it comes time to set up the software and get them all wired up.

ps. i could help you with your solidworks simulations. (if you care, prolly doesn't even matter at this point.) but if you just want to understand it better, let me know.

heres the vid i made last semester (final). im in the advanced class this semester.

[stangtjk]

Nice Stash, at first i was trying to figure where the bearings near the pulleys fit into the equation then it dawned on me!!. . . . . For pulley shafts. . . Yes.?

Yep, the bearings are for the pulley shafts. I need 2 more, I'll probably just get another pack of 10 off ebay, They were only $12 and some change for a pack of 10 shipped but the same seller charges like $4 a piece for them separately.

Cant see any Caps or BR for PS or do you still need source them.?

The large pcb in the center of the photo has 4 IM483H drives and a bridge rectifier attached to the bottom of it and there are 10 caps in parallel on top so all it needs is to be hooked up to the transformer. The three smaller pcbs are the IM805H drives. I'd need caps and a BR for those but I don't have plans for them yet. One of them will eventually make its way to a 4th axis.

I,m just about to make a very similar but smaller machine as yours for my son and dont have any quarms over using belts, infact i would take a bet that it,s just as good as my ballscrew'd machine.?

For a wood router where tolerance's aren't as critical its probably just as good. I intend to find out shortly.

also i may be needing your help when it comes time to set up the software and get them all wired up.

There is really nothing to it to get them working. I hooked mine up just to test them out and I had them working with mach3 in under 10 minutes. All the drives I have are the H series so hooking them up is a little different but they are basically the same drives in a smaller form in order to be mounted to a pcb.
Here is what they look like.

[Zygoat]

There is really nothing to it to get them working. I hooked mine up just to test them out and I had them working with mach3 in under 10 minutes. All the drives I have are the H series so hooking them up is a little different but they are basically the same drives in a smaller form in order to be mounted to a pcb.
Here is what they look like.

i am going to be using emc2 at least to start with, might be alittle more to hooking them up. the only thing i am unsure about is the timings for everything in the im804's thats all i really need to know and ill be set.

[stangtjk]

That video is pretty cool. I wish my college offered courses in SolidWorks, the only progams they used were ANSYS, ProE, and AutoCAD. The first time I tried SolidWorks it was enough for me to abandon all the others but I'm still not familiar with all the features.