[justindewoody]

To cut all those 3/4" Mic 6 aluminum plates, I used the Amana 1/4" or 1/8" Single Flute end mills. I would usually run about 40 IPM with both diameter end mills. DOC for 1/8" was 1mm. DOC for 1/4" was 2mm. RPM for 1/8" was 18,000. RPM for 1/4" was 12,000. I used ALOT of WD40. This Mic 6 aluminum doesn't cut like 6061. It's gummy with usual feeds and speeds that you would use for 6061. I have machined LOTS of 6061 aluminum with NO LUBRICANT...and it all came out just fine. For pocketing, instead of a 50% stepover like I use with 6061, I used a 40% stepover. I had to learn the hard way with the Mic 6. But once I figured it out, it was coming off the machine great. Surface finishes were fantastic.

[justindewoody]

I haven't machined any 6061 with the new machine yet, but I have machined the motor mount spacers from Mic 6. I just did that this morning. This machine is more rigid and heavy than the last machine. Surface finished are even better now. Just FYI...you have to really slow down your spindle when machining the Mic 6. I slowed my RPM down to 12,000 even with 1/8" single flute end mill...and that worked even better. I'm gonna try to slow it down to about 7200 RPM next time and keep federate at 40 IPM. I will report back.

[fretman_2]

Cool...I've got some 6061 I'd like to cut and was wondering what you used. Thanks,

To cut all those 3/4" Mic 6 aluminum plates, I used the Amana 1/4" or 1/8" Single Flute end mills. I would usually run about 40 IPM with both diameter end mills. DOC for 1/8" was 1mm. DOC for 1/4" was 2mm. RPM for 1/8" was 18,000. RPM for 1/4" was 12,000. I used ALOT of WD40. This Mic 6 aluminum doesn't cut like 6061. It's gummy with usual feeds and speeds that you would use for 6061. I have machined LOTS of 6061 aluminum with NO LUBRICANT...and it all came out just fine. For pocketing, instead of a 50% stepover like I use with 6061, I used a 40% stepover. I had to learn the hard way with the Mic 6. But once I figured it out, it was coming off the machine great. Surface finishes were fantastic.

[wizard]

It's an end mill block. I designed it in Fusion 360.

Cool! It looks like you are using some sort of laminated wood, maybe even bamboo, care to tell us what it is?

[justindewoody]

It's layered bamboo plywood. This **** is EXPENSIVE. A 4'x8' sheet is about $205 plus shipping from Green building, construction materials and home decor: Cali Bamboo. Luckily, I found a guy here locally that builds custom cabinets and furniture...and I called him up and asked if he was willing to sell me some of his scrap bamboo plywood (he gets it from CaliBamboo). He was so gracious and helpful. He invited me to his shop and he allowed me to purchase as much as I wanted. And he sold me all of it for his cost. He gets it much cheaper than I can because he buys it in bulk...many pallets at a time. At $205/sheet, that's about $6.40/sqft. He sold me all of it for $3.50/sqft. I got about 3 sheets worth so far. And he said I can come buy as much I need in the future. Great guy.

[adam_m]

Nice build JustinWoody!

I like the pendant who's the manufacturer and where did you pick it up?

Adam,

[justindewoody]

It's a VistaCNC Pendant. Their website is vistaCNC. The model number is P4-S. Works great...and I'm using Mach4. Not all the functions are working just yet, but the guy who makes them is working on getting it to be fully functional with Mach4. All functions work properly with Mach3.

[Uguessedit]

I agree the extrusion needs to go. Better to use thick cast mic6 and bolt it together. His design wouldn’t hurt to run 4 rails using two on the outside and if he insists on a gantry like that to also optimize rigidity besides utilizing extra rails. Only other issue is cross flex and a T top support would probably help that. Never really understood the short Y and ong X or what any advantage would be?: even if it were rigid. As much time spent drawing it up one may as well over engineer it. Otherwise you end up doing what I did and rebuild it 3 times after it’s been together. Not always a bad thing one can learn a lot about mechanics having to redo it over and again.

You have already said that your current machine isn't good enough, what I'm trying to get across is that you will have a less rigid machine. This based on what I say online of your current machine. Plus the linear rails you mentioned would be overkill on the extrusions you have designed in

The arrangement of your table rails and X axis rails is less than optimal. We maybe misunderstanding why you are building a new machine to replace the one you currently have, but if you don't address the rigidity in your current design I really think it will perform worst than your current machine.

I really have no problem with an odd design if it serves a specific purpose. However the long gantry introduces issues you won't have with a shorter one using the same materials. I'd rather see you over build a machine slightly rather then end up with something that is noticeably less substantial than it needs to be. If you want to implement a long gantry then I suggest reading the stickies as there are some good threads there including one that dives into gantry beam design.

[millhouse_]

If you really want to use extrusions make sure to place 20mm or even 40mm solid Aluminium below the linear rails of the Y Axis. The surface of the extrusions is not even. It's concave to the slots. On my build the right rail was slightly skewed after tightening the bolts. With a 80x20 aluminium plate that covers the full profile this won't happen.

Even better is to not use extrusions at all. One large mashinebed, maybe 30mm thick alu and on top of that (left and right) two layers of plane 40mm thick Aluminium bolted together. 40mm is the thickest ready to use plane aluminium I could find on the web.

Extrusions will produce a lot of costs. All the mounting materials needed like T-Slot nuts, screws, brackets. I wouldn't build one from extrusions again. At the end the wall of heavy extrusion is about 5mm Alu that must handle all the motion and weight.

Edit: It's already build... Looks good.

[Project_Hopeless]

My Z axis concept is very similar to your design so I was wondering...

What thickness and type of aluminum are the two main plates? How wide are the plates.

With some time on the machine now, would you have done anything thing different with the Z axis mechanism?

[millhouse_]

The build is not fully ready so I haven't used it yet. But soon.

The Z Axis back & front are 20mm. If I remember correct they are about 170mmx400mm. The portalbackplate is 25mm with an extrusion backbone behind it. Portalsides are 20mm. All AIMgSi1.

Only a few things I would do different now.

The small plates for the ballscrewnuts on the left and right side could have been avoided and the ballscrews mounted direct to the Portalsides or the bottom of the slides, making it a little lighter and more rigid. The X ballscrew would be better placed between the X Linear Rails but I haven't had the option to mill pockets. To align the Z Axis easier the connection from the linear blocks with the back could be better designed. It is a pain in the ass to align this, since there are screws from every side etc.. Another one is go direct with ClosedLoop Steppers or Servos, but that can be fixed in the future. And of course don't use extrusions for the frame.


Your way of designing the portalsides is much better.