Aluminium Gantry Router

[Schuimpge]

If you look at the pictures, there's that piece of wood in the background.
It's supposed to become a sign-board for house-number and name.

That piece of wood is the reason I started checking on CNC machines...

Cheers,
Luc

[Schuimpge]

If the extrusions come from the same manufacturer as some of the fasteners, then I think DBasix it should be.
http://www.dbasix.com.sg/product_list01.asp?id=605 Looks very much like the 80x80 profile I'm using, except for the star shaped bolt holes.
Fasteners are the same though.

Cheers,
Luc

[Schuimpge]

Got my miter saw and started with dismantling everything again.
Cut the cross members to 840mm and went for total length of 1300mm to match the 80x80 extrusions.
Fitted in 6 feet and after bolting everything up I put the Aluminium bed in which had a perfect fit.
Had to use a rubber hammer to slowly tap it in and the last tap went like: tap...bang..
Just popped in perfectly. Solid table now

Seems I can't upload pictures..will be tomorrow for that then.
Also starting on the end plates for the X-axis tomorrow

Cheers,
Luc

[Schuimpge]

Pictures...


Detail Corner


Right side.. 3 feet and 5 'tabs' to support the 80x80mm beam that will come on top.


Basic frame finished. Instead of 4 cross-members total, now its 2 full width extrusions at the front and back, 4 in-between.
Each cross-member has 3 corner supports at each side, total 6. Front and Back have total of 4 each.
Very strong frame already before the next step.


Legs... Still in full up-position. Will later lower them, just easier like this to work on it.


Added the sides. They've been bolted down to the 5 tabs in the second picture.


And finally the Aluminium slab in. The fit is so tight that I had to slowly 'hammer' it down with a rubber mallet.
The last bump I gave it returned me this real satisfying: Peng...


Close-up of the corner, all perfectly flush and ready for a nice big end-plate with 6 bolts to hold the motors.

Cheers,
Luc

[Schuimpge]

Awerby, after putting 6 bolts in the top-plate to tighten it down.. (3 in the front, 3 in the back) I hope you'll tell me that's stiff as non else I've ever seen?! lol

But in all seriousness: Any comments of experts on the site regarding stiffness?
There's a total of 32 brackets for the 6 cross-members. Then there's the 10 brackets that hold the 80x80 beam on top of it.
Last, there's the aluminium plate that is really push-fit but will still get 3 bolts on front and 3 on the back to lock it down to the cross-members.

It feels rock-solid.

Cheers,
Luc

[Schuimpge]

Not done too much but got 2 end plates finished and bolted down the bed. Need more screws for that later on.

Hmmm, pictures upside down and don't seem to be able to change them.


Ok, End-plate for the ball-screw..still thinking to also bolt it into the cross-beam.


Both done.. first try and fits nicely. Square and tight fit.

Cheers,
Luc

[Schuimpge]

I'm starting to think on the gantry and what would be the best way to maximise strength.
The bed is 800mm wide, with 80mm beams on both sides.
Using linear rails either on top or to the sides for the gantry. They're 16mmm rails with 2 bearing blocks each. 1200mm long.

Thinking to bolt a 160x40mm extrusion to the front of a 80x80 extrusion as per below picture.
Probable add a steel plate to the front of the 160mm extrusion to provide a flat surface for the Z-axis.
Sides will have Alu-plates, probably 10mm thick.


L-shaped Gantry, the stack of plates with the router is just to get estimates on the total width of the gantry.
To enhance strength, I can add L-brackets to the back of the 160x40 and the 80x80 extrusion.
Will use bolts drilled through to attach both together.


Optional 40x40 extrusion as a backing.. But I think it will make little difference to using angle brackets.

I do have 2 more 80x80 extrusions that I can use.

Any suggestions?

Kind regards,
Luc

[wizard]

I'm starting to think on the gantry and what would be the best way to maximise strength.
The bed is 800mm wide, with 80mm beams on both sides.
Using linear rails either on top or to the sides for the gantry. They're 16mmm rails with 2 bearing blocks each. 1200mm long.

How much 160 X 40 do you have? Is there enough for two length to cover the gantry span. I'd consider tying two together with top and bottom plates. If not plates tye them together with some 80/40 extrusions.

Thinking to bolt a 160x40mm extrusion to the front of a 80x80 extrusion as per below picture.
Probable add a steel plate to the front of the 160mm extrusion to provide a flat surface for the Z-axis.
Sides will have Alu-plates, probably 10mm thick

I would strive for forming a box if you have the materials.

L-shaped Gantry, the stack of plates with the router is just to get estimates on the total width of the gantry.
To enhance strength, I can add L-brackets to the back of the 160x40 and the 80x80 extrusion.
Will use bolts drilled through to attach both together.


Optional 40x40 extrusion as a backing.. But I think it will make little difference to using angle brackets.

What you will want is support behind the area where the linear rail will be mounted.

I do have 2 more 80x80 extrusions that I can use.

Any suggestions?

Kind regards,
Luc

Think box sections.

[Schuimpge]

Hello Wizard,

Thanks for your quick reply. I have not much of the 160x40's. 2 pieces of 690mm each that need to be supported by a full length extrusion.
Can get more of these shorted pieces, but don't think it'll add strength if you have to use 2 to span the gantry opening.

I plan to have 1 rails on top of the gantry and 1 rails at the front lower part of the gantry. Then an inverted L-shape carriage for the Z-axis.
With that in mind, following options make sense to me:

Option 1: Stack 2 80x80 extrusions with 3mm steel plates front and back and a steel plate on top.

Option 2: see picture, same as Option 1 but with the 160x40's bolted to the front..


Option 3: see picture again.. this makes most sense to me, metal plates on top and front for the rails.
Saves a bit on weight but holding most of its strength.


Option 4: Skip the Extrusions completely and go for a single Box Section 5mm Steel beam. 120x120mm size.. (not favouring that, but as a last resort)..

What you think?

Cheers,
Luc

[Schuimpge]

Just to be sure: SBR16 fully supported Linear Rails..
Future might see them replaced by HiWin equivalent rails, but for now, don't want to stretch the budget to much.
Still need the ballscrews, which will be the most expensive parts for now.
Thinking of buying a set of 4 screws (RM1605, 1500mm x2 for X-axis, 1200mm x1 for Y-axis & 450mm x1 for Z-axis)..
Set including end-blocs and nut are offered on eBay for USD 360 in total.
Not in a hurry, but start checking on it.

Cheers,
Luc

[Schuimpge]

Wizard, if I take option 3, then have two equal angle steel corner sections of 80mm with thickess of 6mm covering top and front and bottom and front..
Thinking that would be the best option of having a straight facing for the rails and the corner brackets would give enormous extra strength to the overall structure.
Then I can start straight away with first bolting the extrusions together and then order 2 steel sections..

Cheers,
Luc

[wizard]

Wizard, if I take option 3, then have two equal angle steel corner sections of 80mm with thickess of 6mm covering top and front and bottom and front..

Looks like it is making good use of what you have available.

Thinking that would be the best option of having a straight facing for the rails and the corner brackets would give enormous extra strength to the overall structure.
Then I can start straight away with first bolting the extrusions together and then order 2 steel sections..

Cheers,
Luc

The only thing to watch out for or to consider, is the different expansion rates of steel and aluminum. This could cause you trouble if you get huge temperature swings where you are at. I'm imagining a Thailand right now where the temperature is perfect all year around and this won't be an issue.

[Schuimpge]

Thanks for your time and information as always... Good to go then. Afternoon need to get a larger drill-bit for the bolts I will use to put the aluminium together.
This morning giving electronics a first try. Got drivers, so trying to figure out to get them turn an old Nema17 motor.. Should be fun testing.

Weather here is fairly constant. Coldest we have is December - January where occasionally it could go as low as 18'C at night but normally its between 28'C at night and 35 - 40'C maximum daytime.
Given that the front is a 2 piece 160x80 Extrusion, might help in keeping things in check. Aside from that, on a 1300mm Gantry, the effect should be minimal if measurable at all with those temperatures.

Cheers,
Luc

[Schuimpge]

That was fun.. Got the drivers and arduino connected and working thanks to the excellent ZenWorks instruction.
Only for the software I had to resort to a simple sketch, but all works.

So another hurdle taken, many more to come, but will go and start playing with GRBL to figure that out.
From there, trying to send G-Code and see if I manage that.
Then it will be easy to get the rest done as well.

Cheers,
Luc

[fretman_2]

I'm also going to use an Arduino Uno. I have the ZenWorks instructions also. Did you use the enable on the Arduino?

That was fun.. Got the drivers and arduino connected and working thanks to the excellent ZenWorks instruction.
Only for the software I had to resort to a simple sketch, but all works.

So another hurdle taken, many more to come, but will go and start playing with GRBL to figure that out.
From there, trying to send G-Code and see if I manage that.
Then it will be easy to get the rest done as well.

Cheers,
Luc

[Schuimpge]

I'm also going to use an Arduino Uno. I have the ZenWorks instructions also. Did you use the enable on the Arduino?

Hello Fretman, I followed all connection instructions on ZW. After that I used the below instructions for very basic testing.
Do note that pulse and DIR are reversed in those samples compared to ZW instructions. So either change on the hardware connections or change in your sketch

Cheers,
Luc


http://www.schmalzhaus.com/EasyDriver/Examples/EasyDriverExamples.html

[Schuimpge]

As planned, got most of the work on the Gantry Base done. Ran out of screws for the front 160x40 extrusions.
1 side is fully attached, the other side still missing 6 screws. This weekend I hope.
Quite heavy and sure very strong structure. With the 2 profiles covering top, front and bottom, I'm sure for it to be a very stable base for the Z-axis.







Cheers,
Luc

[Schuimpge]

Well, my rails arrived, steel arrived, and only managed to do a tiny bit the whole weekend. Had a company night out.. was wasted thoroughly Saturday, but did get a few hours in on the steel.

Corner steel is 75x75 @ 5mm. Only thing I did not check properly is the inside corner, which is too shallow to fit the extrusions.
So lots of grinding to do. On Sunday morning started and managed to do 2 of the 4 steel sections. One of them mounted with only 2 screws for now, still need to find a larger drill bit to countersink the bolts I'm using.

Loose fitted the rails and the gantry, runs very nicely, as it looks, I'll get about 130mm clearance to the aluminium bed.

Off to the airport for a trip to Myanmar first.. Next weekend I hope to get some serious 'bolt-fitting' done.
Undecided as of yet whether I'm going to use epoxy. Might for now skip that and put it as a possible 'future upgrade'.

cheers,
Luc

[Schuimpge]

Lots of sanding and of course drilling the mounting holes still to do.
Will take a lot of patience to get this part right.
So far, rails run very smooth, one finger push and it rolls away.

Cheers,
Luc

[Schuimpge]

Well, nice weekend finished. Quite some work done.
For best positioning of the X-axis rails, I figured best to start work on the Gantry and base for the Z-axis first.
Started drilling and tapping for the steel first. And subsequently got the bottom rails on also.

Because I have 1200mm rails on the gantry, I decided to use the full length of an 20mm thick aluminium block on the top rails to maximise stability of the Z-axis. The top is 350mm wide, and connection to the bottom rails is done with 2 more blocks with same dimensions.
Now it's only 4 screws connecting all that, but it will be braced later to make a very rigid structure.
Z-axis clearance still on target at 140-150mm. Plenty enough.

Curious as to what you guys think. Hope it will give me a very strong setup. For now it's moving nice and smooth along the gantry.
Spacing of the carriages moving the gantry on the X-axis will be about 25cm, giving me a work-area of approx. 1000mm x 850mm
The gantry is getting pretty heavy, no weighing scale yet, but think it will end up at about 45kg.

Question: Plan is for Nema 23 motors at about 400 Oz/Inch. Given the size and weight of the gantry, is that acceptable? Or should I look at Nema 34?

Question 2: Getting closer to ordering Ball-Screws.
- My rails are 1200mm, so ball-screws should be of the same length? or slightly longer? or?
- Rails are 16mm diameter, will ballscrews of the same diameter do?

So far quite happy with it. Even without any serious adjustments, I'm very close to perfect 90' to the table surface.
I am getting worried about the supporting table, as it's not strong enough to support the machine when operational. So a steel table will be on the list of to-do's in the coming weeks.

Thanks and regards,
Luc