Heres a way of quickly and accurately designing & making front panels which i have found to work extremely well…
The basic concept is that the stencil for the various cutouts and holes to be drilled is drawn on computer with XARA (in my case). This is then printed to scale on A4 sticky back paper, a large design can be spanned across several sheets. This is then stuck carefully onto the back of the pce of metal being worked. then the panel is drilled carefully from the back through to the front.
When all the holes (etc) have been drilled, the sticky sheet can be removed; though it wont matter if it doesnt all come off.
In Full,
A good 2D cad or drawing program is used to create the drilling/cutting stencil; i would reccomend XARA, as it is cheap, increadibly stable & does pritty much everything you need. The Page layout is set to work in inches (or millimeters), and the size scaling is set to 1:1.
It is then a good idea to draw the overall outline of the pannel with the box tool (dimensions can be set precisely by entering them directly into the value boxes). Set the colour of the box fill to white, the boarder to black & the linewidth to 0pt (apply this to small parts drawn on the panel). This box then can be used as a refrence as to where the cutouts & holes shall appear on the panel.
Next draw the various cutouts & holes; it is adviseable to draw small (1mm) circles where pilot holes & corner roundings will go. ..this will really help take the guesswork out of drilling ! Also, if the holes are drawn as circles instead of crosshairs (showing the centerpoint), it will be clearly seen if the hole is slightly out …or has been drilled too small ..etc.
Also, you may want to draw the outline of the overlap that a cutout leaves you, before it is visable; which will help alot if a hole does go slightly wrong & you need to improvise by moving its center very slightly…
There are two extra tools within Xara (and other programs) which will save alot of time messing around:
One is the alignment tool, which allows you to auto arrange shapes/objects on the page relative to eachother in various fashions. ..for instance the pilot hole point can be automatically perfectly centered on the cutout for a rotary knob.
The second is the clone array tool, This will take all the work out of drawing & aligning repetitious stuff like the line of knobs on the midibox 64. This works by making and positioning the cutout for the first knob in the row, then copying it to where the row ends. The tool is then used to select the start&end shapes, and the number of clone objects between those points is entered. this will create a evenly spaced array of idential objects ‘instantly’. These arrays (button/knob/led banks) can then be copy/pasted to create more lines… etc.
When the final design is ready, it will need to be ‘mirror imaged’, before it can be printed to work as a back surface cutout template. when this is done, it can be printed out onto sticky back paper…
Apply the label carefully to the back of the metal (etc) sheet that you will be working on. Then it is a good idea to put masking tape all round the edge of the metal, holding the edges of the label down; this will save your fingers from a slicing & help keep the label securely in place.
Then use a centerpunch and hammer on the marked pilot hole points; this is best done with the sheet on a hard & non abrasive surface (a good solid wood worktop) …which will help stop the centerpunch from distorting the metal beyond the intended drilling zone. If you centerpunch and pilot hole, you are more likely to get a accurate & tidy end result, though it is possible to drill without them …though if so, at least use a pillar drill & sharp bits.
Drill out the pilot holes & then do the rest of the drilling; the most accurate tool for this is a small workshop pillar drill (screwfix.com £40 ferm), though good results can be had with a handheld drill. You may want to try using titainium coated or cobalt drill bits ..as they cut far more efficiently.
When it comes to deburring, there are two tricks to getting the rough edges off the holes; one is picking up a drill bit two sizes larger than the hole & turning it on the hole with a little force to peel the burr away. The next is getting a average set of 10" wood/metal files (often £6-10 for 5), and using the shape of file most like the hole on the inside edge of the hole. …if these two tricks are used togeather, very good results can be had.
As for cutting out the hole for the likes of the lcd panels, this can be done by drilling a line of holes along the innerline of the cutout (dont try joining the holes up, it doesnt work), and then cutting through the remainder with a coping saw + the metal blade (wilkinsons sell them for £3). This will now leave a hole which has a cerrated inner edge, this can be filed patiently down to the corect shape using a 10" flat faced wood/metal file. Use the small circular one to round out the corners if needed. Fine wet&dry sandpaper against a pce of wood can then be used to take the rough appearence out of the filing.
One way to get a nice front panel finish with minimum fuss, is to use a belt sander with a medium/fine belt on it, carefully run this over the fixed down (…dont want it in orbit, or your groin!) panel so that a brushed effect appears going in one orientation across the pannel. ..after wiping any metal dust off this can then be laquered over to stop it corroding. In the near future i shall do a properly done webpage article on this & other useful stuff; though right now im kinda busy.
Oh …and the other great thing about working with computer generated stencils; you can print it out as many times as you like, to make as many identical panels as you want without the hassle of redrawing onto the metal each time !
Have fun, and be careful with those powertools ![]()