John's Alu Profile build

[mekanik]

Hi John
Regarding vertical mounting you will have to build yourself a substantial base, if you make another post asking for ideas for designing a vertical assembly machine Dean(JAZZCNC) might give you some advice regarding this, he has a video of one of his larger builds but i couldn't find it.
Regards
Mike

[Evengravy]

Hi John
Regarding vertical mounting you will have to build yourself a substantial base, if you make another post asking for ideas for designing a vertical assembly machine Dean(JAZZCNC) might give you some advice regarding this, he has a video of one of his larger builds but i couldn't find it.
Regards
Mike

Okay, thanks a lot, I'll have a think about some options.

[JAZZCNC]

Hi John
Regarding vertical mounting you will have to build yourself a substantial base, if you make another post asking for ideas for designing a vertical assembly machine Dean(JAZZCNC) might give you some advice regarding this, he has a video of one of his larger builds but i couldn't find it.
Regards
Mike

That would probably be this 8x4 then. 10 x 5 with a Vacuum bed will be coming soon if I ever get out of this bloody house again.!!.

The vertical machine works amazingly for large machines with no downsides other than cannot use it as a bench. The advantages are many and I wouldn't go back to a horizontal machine if larger than 4x4. That said I'd still have a vertical machine under 4x4 for some of the hidden benefits like longer tool life and better chip management but below 4x4 the space-saving isn't so great.

Regards the filling of tubes then I've tried sand and while it does help a little it's not a massive difference. Don't fill tubes with concrete because it can shrink, it also doesn't mix well with aluminum. Expanding Foam and Silicone etc don't do diddly squat so don't waste your time money.

The best thing I found is to use a thicker wall tube in the first place and brace it well. Regards the aluminum profile then if you use HD version then you shouldn't have any issues with vibrations and I don't think to fill the voids with Epoxy granite will dampen to any great degree but it will certainly affect performance because of the extra weight.

[Evengravy]

That would probably be this 8x4 then. 10 x 5 with a Vacuum bed will be coming soon if I ever get out of this bloody house again.!!.

The vertical machine works amazingly for large machines with no downsides other than cannot use it as a bench. The advantages are many and I wouldn't go back to a horizontal machine if larger than 4x4. That said I'd still have a vertical machine under 4x4 for some of the hidden benefits like longer tool life and better chip management but below 4x4 the space-saving isn't so great.

Regards the filling of tubes then I've tried sand and while it does help a little it's not a massive difference. Don't fill tubes with concrete because it can shrink, it also doesn't mix well with aluminum. Expanding Foam and Silicone etc don't do diddly squat so don't waste your time money.

The best thing I found is to use a thicker wall tube in the first place and brace it well. Regards the aluminum profile then if you use HD version then you shouldn't have any issues with vibrations and I don't think to fill the voids with Epoxy granite will dampen to any great degree but it will certainly affect performance because of the extra weight.

That's awesome! This has given me some ideas for sure... Design wise it's not a million miles away from mine, I really wish I could weld. Maybe I can think of something I could make work using aluminium profile.

Ten four on the cement filling. I think I'll go with sand on the Y rails that don't need to move just for the added benefit, and try some test pieces for composites on the X gantry, to see if it's worth the hassle. I can't recall if it was HD rails, it was this type of profile from Dold Mechatronic: https://www.dold-mechatronik.de/Alum...-type-groove-8 maybe there is heavier type out there and that was my mistake.

[JAZZCNC]

That's awesome! This has given me some ideas for sure... Design wise it's not a million miles away from mine, I really wish I could weld. Maybe I can think of something I could make work using aluminium profile.

Welding isn't that hard, esp if you can get your hands on a Mig welder. You can even hire them from some a decent hire shops.
The welds don't need to be industrial strength. Steel is very forgiving so it allows you a few attempts if get it wrong and along with a grinder you can hide all your screw ups away.

I can't recall if it was HD rails, it was this type of profile from Dold Mechatronic: https://www.dold-mechatronik.de/Alum...-type-groove-8 maybe there is heavier type out there and that was my mistake.

That is the ITEM "L" section the "L" stands for light. It's exactly what you see on that vertical machine but I'm using the heavier version which doesn't end with "L".
However, I've used the "L" on many machines and it works perfectly fine so I wouldn't be too worried.

[JAZZCNC]

If you are going to do vibration tests then I wouldn't waste time testing individual pieces of profile or steel etc off the machine because all that matters is the tool. Testing at the tool is the only thing that matters IMO. You'd be better investing time on designing a strong Z axis.

[Evengravy]

If you are going to do vibration tests then I wouldn't waste time testing individual pieces of profile or steel etc off the machine because all that matters is the tool. Testing at the tool is the only thing that matters IMO. You'd be better investing time on designing a strong Z axis.

Yea, that's a good point. I did a bit more reading around the subject and a guy on CNC zone recommended pea gravel in the non moving parts and nothing in the gantry, for now. I'll try that first and see where it is. I actually have a MIG that I bought years ago but never got around to learning to use the thing, a gas-less 150 from draper (I'm not sure if they're much good). It's been shelved in my dads place for years but maybe it's time to dust it off.

I think the Z axis I have is pretty solid though, it's foundation is milled from stainless. I know the opposite arrangement than most recommend, with the rails on the z plate which seems to be preferred, but it was a simple solution for me. I've tried to keep everything as close to moving bearings and having as little overhang as possible. The Z only has 100mm of travel but after using my other machine for a few years I realised I've never needed to mill anything over a couple of inches thick so the z overhang was really compromising the strength. That plus the momus design is not very good generally. Live and learn. I thought it would be a good idea this time for me to keep the gantry and Z axis as tight to the part as is feasible.

It's a shame about the profile, maybe I'll change it for something heavier but at this stage I might just run with it and see how it does, should be easy enough to swap it out for a heavier profile down the line.

[JAZZCNC]

I think the Z axis I have is pretty solid though, it's foundation is milled from stainless. I know the opposite arrangement than most recommend, with the rails on the z plate which seems to be preferred, but it was a simple solution for me. I've tried to keep everything as close to moving bearings and having as little overhang as possible. The Z only has 100mm of travel but after using my other machine for a few years I realised I've never needed to mill anything over a couple of inches thick so the z overhang was really compromising the strength.

There's nothing wrong with rails on the rear plate, I've built dozens of machines using both methods and neither is better than the other because the difference between them is hardly anything and any advantage one as over the other is mostly dependant on machine design and user needs.
In your case with a short Z-axis, it's the best method because it allows you to make the most out of a short-stroke while allowing you to keep the gantry low and squat giving the best strength.

Edit:

Don't worry about the profile it will be fine. If you using my "L" Gantry design just make sure you bolt it together well.