Can’t Remember How to Square Up Material Stock ready for CNC ?
I sometimes have to dig deep in the odds and ends heap of rough bits of materials to use on a project. This results in having to square up the find so it can be easily programmed into Fusion CAM. I always have to scratch my head on the process which is well documented by Tom Lipton and This Old Tony among others. What I needed was something to pin on the wall to remind me.
The result of this frustration is a write up and a graphic which you may find useful. Here is a screenshot and the link below it provides both this document and the write up in a ZIP file.
I’ve made mention in another post of the arrival of the Tormach microARC to use on my Tormach PCNC440 CNC milling machine. The microARC provides a 4th axis facility.
To date I have used this with the supplied chuck but there have been a couple of instances where a vice style stock mounting would have been useful. I am indebted to David Loomes for bringing the Xin Dian centralising vice to my attention.
This is available from various sources on the Internet and at a delivered price of less than GBP100. It is a lovely little vice. It is supplied with an industry standard backing plate which is held in place with four M6 cap head screws. The supplied backing plate is not suitable for mounting on the microARC .
A 3D model of the microARC is available as a Fusion file and this with some careful measurement allowed me to model a mounting plate for the Xin Dian to fit onto the microARC face.
As a secondary activity I edited the Fusion file to provide a simple sub-mounting plate for the Xin Dian vice on my PCNC440 tooling plate.
Details of both these mounting plates are contained in the PDF link below.
There are a number of lower cost CNC milling vices (vises) available on the market that do not have jaw geometry with grooves for tooling fixtures and vice stops. Admittedly their jaws could be machined to add this facility but many of these vices have hardened jaws which presents more of a problem.
My CNC vice came from the UK supplier ARCeurotrade and is from their ARC Versatile SG Iron Milling Vices range. I have the 100mm wide jaw version and the jaws are just over 11mm (7/16″) thick.
I have a simple plate that acts as a stop that is flush with the end of the jaws. This makes use of existing holes in the vice body but often I need to have a stop internal to the jaw footprint. Juggling then results with all manner of Heath Robinson solutions.
My design is simple and clamps onto the thickness of the jaws.
There are two M3 clamping screws and there is enough adjustment on these to allow a parallel to also be gripped should it be needed.
I allowed for two positions for the stop rod and the rod is held with a grub screw in each. There is a central burr clearance neck on the rod so the grub screw does not damage the surface of the rod and make removal difficult. Clearly the rod could be simplified to have just a single fixed position.
The rod can have rounded ends or it can have ball bearings glued into a cavity on each end of the rod. The ball bearings would give a higher resilience to damage.
So nothing really complicated or rocket science with just an hour or so of workshop pleasure. The size can be adjusted to suit your vice jaws and the material can be whatever is in the junk box.
Here is a link to the 2D drawings that were created in Fusion 360.
When I bought my Tormach PCNC440 in 2016 I included the enclosure kit in my order. On receipt I thought that fitting the enclosure would dominate the size of the workshop so I never got round to fitting it. It has sat in its shipping box since then. I have consequently shared quite a bit of my swarf (chips) with long suffering family.
After a recent (particularly heavy) CNC run I had a serious covering of swarf in the machine tray and because I had no enclosure round the mill, I had quite a lot distributed further afield (i.e. into the house). Domestic peace was becoming an issue. Time to do something about it.
Out came the enclosure kit, cobwebs dusted off and around three hours later I had the enclosure fitted. I have to say it looks good and does not overpower the workshop as I thought it would. My wife is impressed and says it looks a more professional machine and ‘if you had it why didn’t you fit it before now’ ?
The fitting did however create some follow up problems.
My control monitor had up to now been mounted on the side of the 440 on a standard ISO TV mount. With the enclosure fitted this meant it was ’round the side’ and difficult to get to. I debated a new long reach ISO but they are expensive. Plan B was to make something. I rummaged around in my aluminium stock and with the help of Fusion 360 came up with a seriously overengineered extension arm to add to the existing ISO mount. This would allow the monitor to move forward to be in reach at the front of the mill.
This bracket became the first CNC job to run after fitting the enclosure. I am pleased to say it was the cleanest my workshop floor had ever been after running a job.
Having fitted the new bracket and mounted the monitor, all the cables needed extending. Fortunately I had had the foresight on my original order to include the extension cable kit. As a result I only had to extend the power supply lead from the monitor 12V ‘brick’ supply.
The second issue was where to mount my ITTP probe as this had formerly mounted on the side of the 440. With help of some more Fusion design I modelled a corner mount that picked up on the enclosure fastenings.
After that first heavy machining run I noticed for the first time the slight smell of the mist coolant when opening the enclosure doors. Before the enclosure was fitted the smell must have dispersed into the general workshop air. With the enclosure fitted the air was concentrated inside the mill and I only got the smell when sticking my head inside. While it had never been a problem (as far as I can tell …) I thought I should do something about it.
Sometime ago I installed a ceiling extract duct in the workshop. This vents to the outside world via a custom roof tile. Normally the system sits with a flared cowling (made from a cut down flower pot) on the ceiling entry duct. The system normally acts as a background trickle extract. The cunning plan in the design was to use various pipe components to provide bayonet style connection pins (Nylon screws) to allow extension trunking to be used. A bit like a BNC RF connector if this is familiar to you. This would allow me to use an add-on length of expanding flexi trunking to bring the extract nearer to any heavy fumy activity such as welding or oil bath hardening.
With the use of further scrap odds and ends of aluminium, I mounted a pair of support bars across the top of the new 440 enclosure. These would fix the ducting over the enclosure during heaving CNC sessions. Not a total solution but certainly one that will reduce the general smell of XtremeCut 250C when I stick my head in the enclosure.
A good day’s activity with all the issues addressed and domestic bliss hopefully restored.
I have mentioned my activity on the Thwaites clock in a couple of blog posts and I can now confirm the work is complete.
This has been an interesting challenge and I am pleased with how it has worked out. Once again I am impressed by the way that modern techniques and technology can all play their part in achieving a result that once upon a time would have been impossible using traditional circumscribed knowledge.