Drill depth DRO Using Powerfix (Lidl) Vernier Calipers

Description

I've got a cheap pillar drill that I picked up for a song a few years back. It's not top quality, and you certainly couldn't do precision work with it. But, it's what I've got, and it's fine for my woodcraft. One of the most hilarious features was the depth gauge/stop. Not only was its scale extremely coarse, but its pointer had a habit of swivelling away from the scale when the motor was running. I already had a Powerfix vernier caliper, bought from Lidl UK. It cost a tenner (all but a shiny penny) and was surprisingly good quality. In fact, it's been an important contributor in every design I have made on Thingiverse to date. My big bruvver suggested it was ideal for adaption to use as a drill depth gauge. So the very next time they appeared in Lidl, I grabbed another one to do exactly that. My drill had a rather natty little flip-down safety shield that was supposed to cover the work area when in use. But all it ever did was get in the way when it was flipped down, and (ironically) jab me in the face when it was up. Because of that, I dismantled it a few years back, but I'd had to leave its mounting plate because it carried the fixing for the depth gauge/stop. Now I was changing things it could be finally removed, but in order to keep the depth stop functionality, I would need to add a matching fixing point in the new part. Mind you, getting the old plate off wasn't easy: The drill wasn't supplied with tools to remove the chuck. and the original mounting plate wouldn't open wide enough to clear it. I made a few attempts remove the chuck, using improvised tools, but it wouldn't have it. I ended up heating the plastic mounting plate enough to distort it over the chuck. To avoid this with my design, I decided that it would be in two halves to make removal and refitting easier in future. The next problem was the fixing for the upper caliper jaw. Fortunately there was a narrow 8mm lip at the bottom of the pillar drill's cast body. It wasn't ideal, but it could definitely take a slimmed down version of the lower clamp. It wouldn't be as strong as the lower fixing, of course, but it was good enough. My original plan was to drill through the caliper jaws and to fix through them into the new clamp rings. But the calipers were tool steel, and my HSS bits managed about 0.5mm before becoming blunter than a yorkshireman looking at modern art. I bought some cobalt drill bits but they did no much better. In fact, the last cobalt drill bit left its cutting face embedded in the caliper whilst the remainder of the drill bit looked like an exploded cigar in a Bugs Bunny cartoon! I've attached a picture of this to prove I'm not exaggerating - my Mum told me millions of times not to exaggerate. So, reluctantly, I changed my design so that the caliper jaws slotted into housings on the clamping rings, and were then pinched into place with a machine screw. I ended up chopping off the caliper's internal measuring jaws with my angle grinder because they kept jabbing me when I reached for the on/off buttons on the left of my machine. Later on, I chopped off a large piece of the measuring scale as it interfered with access to the drill's pulley housing. I hadn't planned to do any chopping at first, but when I made a second type of caliper mounting, to my brother's specification, for his similar Parkside drill press I realised it made sense. He was also far more adventurous than I was, and succeeded in not only drilling his caliper, but completely dismantling them so that he could hack them in a much more aggressive fashion. My design for HIS machine has been posted as a remix for those who wish to go this route. So, a tenner's worth of digital accuracy procured at the same time as I bought my potatoes!

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