Thread: Wobblycogs CNC Mk1
What I do when I've got something like that to do is like Martin said make a template and I can use that to mark the brackets and also the mating piece of steel. I drill 3mm holes at the position I want them and then I've got a 3mm centre punch (old snapped off drill bit ground down and sharpened) that I punch the marks with. That way I can get both sets of holes matching, as long as I clamp it in the right place of course :)
I'm going to chop up the remaining angle for you this week, do you want any more angle brackets cutting whilst I'm at it? ;-)
Worry not :-). I'm using the brackets as a jig in the way you describe, I even splashed out and bought myself some transfer punches to help.
Neil, I'm going to be bold and say I don't need any more brackets. If I do manage to screw it up I'd probably need a whole new set anyway. My attempt to cut a bracket by hand for testing makes me even more grateful than I was before for your help, I damn near broke sweat :-).
Shouldn't be a problem cutting something like that as long as you are doing it correctly, don't buy cheap hacksaw blades as they are useless for anything harder than cheese, I mean process cheese, cheddar would blunt them to quickly.
Don't try & force the blade to cut the material, let the saw do the work & you will be surprised just how easy it is with a little practice. I've got power saws for just about everything from wall mounted panel saw to cordless jig saw but still like to get a hand saw out from time to time just to keep my hand in for those occasions when a power saw is not an option.
lol, exercise. I don't have time for all the things I want to do let alone doing things I don't want to do :-). The blade I've got in there at the moment is cheap and nasty and I used it for cutting some stainless steel last year so it's a complete toothless wonder. I ended up using the jigsaw which gave a surprisingly good cut even if it was a bit tricky on the corner.
Right, time to get on and actually build something...
Quick update to say that I've started making the frame and so far so good. As I said to the wife, nothing that scrapping it and starting again couldn't fix anyway :-).
Joking aside I'm actually fairly pleased with my first real foray into the world of metal work. There have been a couple of minor hiccups but nothing that I can't fairly easily work around, the most serious problem has been breaking a centre drill in a hole I had planned on tapping. Unfortunately for me I tried to drill it out which caused the drill to wander as it bounced off the broken end of the centre drill effectively ruining the hole forever. 'Tis not a big problem though as there are three other bolts holding that side of the bracket on and it was only a bed bar anyway.
I made this jig for drilling the brackets which came in really useful:
The studs are pieces of 7mm shank from an old drill bit. I slipped the bracket over the two studs to ensure it was perfectly aligned for the other two holes. I now have 26 brackets with identical hole patterns.
So far I've put together the bed and part of one of the sides. I'm going to try and get a leg or two fitted tonight.
I'm completely fed up with drilling an tapping holes :-). There's 112 tapped holes in the bed alone which is less than half what the machine will have when complete. I'm also going to have to add some more bracing to hold the frame square I think. The bed as shown is stiff enough that I can't noticeably cause deflection by hand but individual members are easy to move so I think it needs more. A few bits of angled bracing should stiffen it up tremendously though I think and give me an easy way to make sure it's perfectly square. I've got a ton of angle section left so I might use that rather than get more steel.
Welding would have been so much quicker but after seeing where it's going to go I fully understand why it has to be to be dismantled!!
The bit that broke in the hole would be hardened so you wouldn't have been able to drill it out with a normal bit anyway, best way I have found if that happens & you don't have access to specialist equipment is.... If you can drill a small hole on the other side in the same place, take a bit of care when you get close to the end of the drill bit or you could end up with another broken bit on the other side lol.
Once you have drilled a hole use a bit of hardened rod to try I tap the bit back out. Does work if you are careful but a bit of mucking about is required so if the hole is not that important then normally best just to drill another one lol.
In the future (possibly a couple of years in the future) at least some of this frame will be welded. I'll probably weld it into three sections - 2 sides and the bed. That will reduce it to just 20 or 30 bolts rather than the hundreds it current is. I've not got anywhere to store the welding equipment at the moment and I wanted to get going so bolting seemed like the least worst option. I suppose I could have got it welded for me or hired equipment etc but I quite like this approach as I'm learning about metalwork as I go.
Shortly after breaking the first centre drill and then wrecking the hole I broke another one (rushing) but I learnt from my first mistake. I grabbed a knackered old spade bit which has a hardened steel point and just drove the broken off tip of the drill clean through the steel. It had broken off most of the way through so it was fairly easy to just force it the rest of the way. That left me with the counter sink intact so it was easy to follow up with the main drill. I'll try drilling down next to it if I break one shallow though.
BUILD LOG: Wobblycogs CNC Mk2By Wobblycogs in forum DIY Router Build LogsReplies: 113Last Post: 10-02-2015, 12:37 PM