Basic Aluminium composite totem sign with inlaid acrylic letters and light panels
Trade Made Designs Job Brief
We were asked by a local sign firm to produce 12no. black Aluminium composite panels with inlaid acrylic lettering and fret cut rectangles to receive lightboxes this was for a totem sign that they were building for a local shopping center, we were tasked with supplying the materials doing the CNC routing plus fabrication of the boxes and inlays, the sign firm would then fit the main lightboxes and install the panels on the totem frame
Making the Aluminum Composite sign trays and lightboxes
We make these types of signs and lightboxes on a daily basis so we are well used to manufacture them, Aluminum composite sign trays and fret cut signs trays are very popular indeed and for good reason not only are they good value for money they are also lightweight, strong and come in a great range of premade colors which helps keep the costs down that is why everyone uses this material within the sign trade
Anyway, we can talk about the material a bit later I just want to go over the basic process of manufacturing these types of sign trays,
Sign tray Manufacture
We were sent a cad file from the sign company which contained the overall size of the totem and their artwork for each of the panels, we checked over the artwork and made some adjustments to the final artwork to ensure it would CNC router ok , once we made the changes to the artwork we saved them and sent the CAD file to our CAM software for machine programming,
How that we have the cad file in our Cam software we program each panel for machining, All the panels are CNC Cut the same way with 2 folded edges left and right for folding around the sign frame, a letter inlay for the acrylic letters which will be illuminated and a basic fret cut window for a lightbox, the only real difference in these panels was the height of the panels some are bigger than other this was to accommodate the design layout and frame structure,
Once all the tool paths we added to the panel it was then sent to one of our CNC Routers for cutting , with these types of composite panels we like to do all the folding work first so in this case, it means simply running the aluminum composite folding tool down each side of the panel as seen in the above image (2 black lines )
After the folding cut is done we then machine in the letter inlays again as above the GHI , the thing about panel inlays which you must allow for is the radius of the cutting tool, when you're cutting the inside of a part the tool always leaves a radius in the corners as it can't go past the inside corner so when inlaying material into other materials you must allow for these internal corner radiuses, luckily most Router software have this command built-in so it makes inlaying a really simple procedure.
How we have machined the panel letter inlay we simply cut the internal rectangle for the lightbox and then we cut the outside shape to final size this keeps everything very accurate, After the CNC panel work is done we remove the panel clean down the machine bed making sure it clean from any shavings left from the previous panel this is very important see tips below for some advice on this
We place on the next sheet reset the program for the next panel design send that code to the cnc router and cut the next panel we just repeat the process for each panel until they are all finished.
Now we have all the composite panels cut its time to machine the acrylic letters which will fit into the panel via our inlay command, for this operation we simply take all the acrylic letters and nest them into our acrylic sheet so we can cut them all at once, we typically machine a 2mm x 15mm shoulder around the acrylic letter face so we can use that shoulder for gluing the letters into the panel,
After the letters are machined out we need to glue them into the aluminum composite panels, this is a pretty basic task simply key down the panels so the glue has something to grip to, lay the panels on a flat surface dry-fit the letters first to check fitment is ok once you're happy with fit and layout apply the glue to the shoulder of the letters and stick to the backside of the panel making sure no glue gets onto the face of the letters or panel, allow to dry before lifting the panels.
After the panels are fitted with the inlaid letters and the glue has cured we just had to glue the very top panel closed which was very easy just fold back the left and right folds and the top fold glue these all together and allow them to cure, once that was done we where finished on this job the sign company fitted the lightboxes and installed the boxes on the totem sign.
Aluminum Composite Material
Just want to go over the good points of this material plus some machine tips on it
Aluminum composite is mainly used for the following reasons
Cost-effective material
Can be machined, folded, roll and even plastic welded
Lightweight and rigid
Lots of prefinished colours in matt or gloss
Ready availability
Great range in sheet sizes from 8x4 to 4x2m
Can be used inside or out
Some tips for CNC Routing this material
Ensure good sharp tooling
Typically single flute cutters as best up profiling operations
Always use a vacuum table to hold down this material
Make sure your bed is perfectly flat and clean before doing any folding work on this material as its very easy to cut right through the material when folding if there is an uneven surface
always cut the material in a climb mill direction this will give the best edge finish
18000- 24000 rpm spindle or as fast as your spindle goes
Don't be afraid to cut the material fast, you can get a better finish by going faster
If you don't have a CNC Router and you are looking for some Aluminium composite material cut or fabricated don't hesitate to give the experts a call we machine this material daily so it's not a problem, just drop us an email or lift the phone we will be glad to help
Contact us :
Email or lift the phone for a chat we are always here to help
Trade Made
tel. 028 302 68623