[dighsx]

Built my first cnc machine last summer (a jrgo with a Xylotex controller, and 269oz steppers) I decided it was time to upgrade to a bigger machine, a bigger power supply and new controllers.

First step was to figure out how to build a new power supply without killing myself. After a lot of reading and then more reading I built a 55Vdc 15Amp supply, with Gecko 202’s and a cnc4pc interface board.

I went a little over kill on the cabinet; I installed four 100cfm fans (2 blowing in 2 blowing out). The cabinet is 30X16X6 inches and weights a ton with everything in it. I also made the cabinet so it’ll hang on the wall. It makes it a lot easier to get at things this way.

Putting the power supply together went pretty smoothly. Once I figured out what I needed and what hooked up where it was easy. I designed the front panel and all the cutouts, and a clamp for the capacitor in VCarve Wizard (Great software, and they’ve got a new version out that really rocks! www.vectric.com)

So I hooked the power supply up to my current machine. With my old setup I could cut (if I was pushing it) around 25ipm. With this new supply I can cut around 100ipm and get rapids around 140ipm. I’ve got a trim router on my current machine so I think if I did any serious cutting I’d slow things down a bit. But man is it cool to see that thing fly after cutting at 15ipm most of the time.

I’m going to take a ton of pictures of this build. My last build I thought I took a lot of pictures but looking back it wasn’t near enough.

[dighsx]

I really like Joe’s 2006 design. I debated trying to cut the parts myself but in the end I decided to leave that end of things to Joe’s expert hands. I ordered the parts and after some fun with DHL the parts came and I couldn’t be happier. Most of the holes are drilled already so putting things together is going to be a lot quicker than my last machine.

Here are some shots of the slides and then the Z-axis assembly. I machined two of the Y-axis slides wrong so I had to order more aluminum. But other than that the build has been going pretty smooth. Getting the U-bolts installed on the Z-axis was a bit of work, but I used a few clamps to squeeze them, and with a little help from a hammer things got done.

Next up is putting together all the torsion boxes.

[sdantonio]

Nice work Jay. The only thing I did differently is to go with steel angle instead of the aluminum.

That warning on the PS is a bit ominous

Steven

[dighsx]

Yeah the PS warning I thought was pretty funny. I figured I just let anyone who might be standing next to it to watch out.

Did you paint your machine and if so with what? I'm going to try using Zinsser Shellac-Base Primer-Sealer and then give it a final coat with enamel paint.

I'm still trying to figure out what I'm going to do for hold-downs too. On my current machine I used T-track, which is really nice. (You can see it in a few of the pics in the last post)

Tomorrow I'm going to start gluing torsion boxes and the Y-axis assembly. Then the painting begins. wee (I hate painting)

[joecnc2006]

Any further progress?

[dighsx]

Ok time for a quick update. I need to get the pictures off my camera yet so they'll come later. But I got the machine painted and put together. Took a little bit to get the gantry on and just right. It's really a two-person job. I haven’t cut anything yet but she moves around real nice. I get some whip in the x-axis screw. I think the distance is too much for 1/2-10. I'm thinking about maybe upgrading to 3/4 or 7/8's. Anyone have any thoughts on what size to move up to?

I'm running it with 269oz motors and it can move around pretty quick (90ipm+) but around 60 or 70 the whip in the long screw starts to get a little interesting. I also think I'm going to upgrade my motors. The 269's do fine but 762oz will nice.

But the build went pretty smoothly. I had to make a few parts for it but over all it was a snap. I tip my hat to Joe for a great job machining the parts.

I'll get the pics up in the next day or two.

[ger21]

You might want to try 1/2-8 2 start. It'll spin 60% slower at the same feed rate.
If you go with the bigger motors, maybe even 1/2-10 5 start. That'll should get you 300+ipm.

Replacing with 1/2" higher lead screws should be a lot easier than fitting larger screws.

[dighsx]

The main reason I was going to upgrade the lead screws was because the one screw is almost 60 inches long and I'm getting whip in it. I was thinking if I got a larger dia. screw it might do better over the long span?

[pminmo]

dighsx,
You might find that using two nuts on your 60 inch screw might help the whip. The more distance between them the better. One nut only needs to take the load the other is just a stabelizer.

[dighsx]

You mean on the gantry right Phil?

[pminmo]

yes If your gantry is 10" wide, put one one each side so you don't limit your travel.

[dighsx]

Thanks for the tip Phil. I'm going to try it out today. If it works that'll be great because I could then stick with the 1/2 lead screw size, which would make life a lot easier.

I'll cross my fingers it works.

[joecnc2006]

yes If your gantry is 10" wide, put one one each side so you don't limit your travel.

Yes i would say it should work, I did think about doing the same thing, but mine runs at 80ipm with very little whipping, also your leadscrew could have a slight bow in it which will contribute to whipping, I had to replace mine once because of this. Just make the larger portion of the antibacklash nut and place a nut into it will not allow the nut to spin and move distance wise in relation to the distance from the anti-backlash nut.

Here is the DWG file for the anti backlash nut incase you need it, to make a part, try it with 3/4" MDF, the nut stepdown is 0.4" and see how it works..

rename the .txt file to .tap



Joe

[dighsx]

Well I promised some pictures so here we go. First is the gantry put together? Then there's a shot of the adjustment box on the gantry. I had to machine the parts for the box, but it wasn't a big deal. Pic 3 is the torsion box before after painting. Pic 4 is a cool shot of me cutting the rails for the X-axis. Looks like I know what I'm doing don't it? Pic 5 is the machine put together before I installed the motors and lead screws.

More pics to come in the next post.

Joe, where did you buy your lead screws? I got my from Enco and they seemed pretty good but I must have some bend in the one cuz I get the whip at the end.

[dighsx]

Ok this next set shows the making of my cutting bed. I got two chunks of 3/4 inch MDF and glued them up. Then grooved it for the T-Track. To attach the T-Track I bored 1/2 inch holes on the bottom so I could attach nuts to the screws.

And the last pic is a shot of the whole thing together.

I ordered bigger motors over the weekend (762 oz NEMA 34's). Today I'm going to machine the extra anti-backlash nuts and try and get them installed.

[sdantonio]

Hi Jay,

I'm a bit confused about your ppower supply (but then there are people out here who will tell you I am easily and possibly permanently confused anyway). You have the sysmotech, which I assume is supplying 5VDC and 55VDC. So what is the need for what looks like a big torroidal tranny and the capacitor in the corner. Or is the sysmotech just supplying the 5VDDC and the 55 comes from the torroidal tranny?

It's a nicely set up box.

When you get to the point in the thread, please spend a little extra time when you describe your limit and e-stop switches with plenty of pictures.

Thanks

[sdantonio]

here is a stupid question regarding whip.

Are you pre-loading your lead screw? This will often cut the whipping down a bit.

[pminmo]

Wow, nice job!!!

[dighsx]

Steven, The torroidal outputs 39Vac at 20amps it then goes into the big capacitor and from there to a bridge rectifier which turns it into 55Vdc at 15amps. I get my 5Vdc from an old power supply I had laying around which is behind the jacks.

I preloaded my lead screws (or at least I think I did) how much should you preload them. I.E. how tight is too tight?

I'm starting to look around for switches to use as limit switches but I'm not totally sure what I should use. I'm open for suggestions. And when I install them I'll post pictures.

Phil, Thanks.

[Jason Marsha]

Great pics Jay. Those 762 motors should allow you to blaze through any material.

Jason