Some days you walk into the workshop and while you know you have long term projects lurking, you just feel like having a distraction therapy day. For me this usually means adding some tooling in some way or other. Yesterday was one of those days.
While looking around I spotted one of my storage boxes with all the parts I had accumulated to make some table tooling grip nuts as shown by Chris at Clickspring. These are similar to a commercial item. As I now have a tooling plate on the Tormach with a matrix of M8 holes it seemed like a good ‘all in one day’ project and would satisfy my therapy distraction.
Chris did not give any dimensions in his write up but there is more detail in his Patreon video which is subscription only. One gem he passed on was using a piece of 1mm thick material to offset the three jaw chuck to create an eccentricity to the locking nuts.
After completing the write up on the Sherline CNC Indexer for use on the Myford for clock wheel cutting, I realised that an important part of the process was the cutting mechanism itself.
I had adapted the Sherline headstock motor and spindle assembly to mount on the Myford vertical slide to act as a secondary cutting source. I use this for cutting clock teeth and for drilling holes ‘off centre’ to the lathe axis for such processes as arbor mounting holes.
Disclaimer : – This post and many others on my website feature references to Tormach and its products. I have no connection to Tormach Inc financially, commercially or otherwise. I acknowledge that Tormach®, Tormach Tooling System®, TTS® and PathPilot® are all registered trade marks of Tormach Inc.
I am a great lover of having enough light to see what I am doing and being of a certain age my optics are not as sensitive as they used to be. I have fitted Ebay sourced Angel Light ring car clusters as illumination lights on my pillar drill press and on my Myford VMB manual mill. The arrival of the Tormach PCNC440 got me thinking of doing the same.
As luck would have it I had a 100mm OD ring light left over from the VMB installation and this was just about dead right to fit the Tormach 440 spindle diameter. All it needed was a mounting boss.
On the drill press and on the VMB I machined up a boss in Acetal which left a mountain of swarf and I was not looking forward to another session vacuuming out the lathe. Then the thought struck me I have 3D printing so why not print a boss ? It is quite funny how you get locked into one way of doing things and then you step back and realise there are more ways to skin the cat. (Is that a non PC thing to say these days ???)
Booted up Fusion 360 and one extrude pull and two extrude cuts plus three clamping screw holes had a design ready to print. Print time on the Sindoh was just under 4 hours. It looked a lot more professional than the Acetal ones.
It also fits like a glove and the three M5 nylon screws lock it in place. I just need find a 12V plug top to drive it.
If you would like the Fusion STL or the link to the Angel Lights on eBay let me know. I have the STL file for the 3D printed a small enclosure to suit the regulator for the Angel Lights from a 12V supply.
I also have the Fusion file for the handles on the magnetically mounted perspex front shield as seen above. The handle mountings have 45mm centres to match the magnet plates which are standard UK sourced magnetic latches.
The Shumatech DRO350 is a kit based digital readout display for low cost vernier scales and can be bought for either a milling machine or lathe. Shumatech appears to no longer trade but I managed to buy the full lathe kit including the box from the UK agent. The US agent is Wild Horse. See previous post from France.
The product is quite well conceived and has a wide range of functions beyond just a basic readout of X,Y,Z scales. The kit was simple to put together and I quickly had it working as a lash up on the bench.
The first problem was the fact that all the connections are configured to come out of the back plate of the plastic enclosure. For my application this was not ideal. The connectors as supplied with the kit also were not the same as the RJ11 on my scale cables.
I created a ‘pod’ in Fusion 360 that would mount on the end wall of the box and carry all the connections. This was 3D printed in black to match the enclosure supplied. Space was tight to fit all the connections into the space and I had to resort to RJ10 style connectors for the scale leads as RJ11 were too large. I had to extend some of the connecting leads. That aside the ‘pod’ concept worked well.
There is significant debate on the internet about the Shumatech design and its apparent instability or flickering of the digits on the display. Opinion seems to be mixed as to where this originates. The PCB design is not ideal with some very long thin power supply tracking and no ground plane screening. My two small scales seemed to not suffer this problem but my long scale definitely had a problem.
Once again opinion on the internet is mixed as to how to overcome this. This ranges from changing the wiring in the readout box for better earthing, leaving the batteries in place in the scales or replacing them with capacitors to add smoothing.
I tried all these to no real positive effect on the long scale. I even tried inductive decoupling of the connections at the scale terminations.
I took a step back and tried to run the scale on a separate 1.5V bench power supply on long leads and lo and behold the problem still existed suggesting it was a power supply pick up fault and nothing to do with the Shumatech electronics.
I had to hand a small 9V to 1.5V power supply module based on the AMS1117 “3 legged” integrated regulator. I connected this close to the scale and ran the regulator input from 5V. The jitter disappeared suggesting it was really about the pick up on the supply to the scale.
I had stock of the AMS1117 chips and SMD caps so I made 3 regulator boards and in Fusion 360 created a small box and lid to contain the regulator module.
The pcbs were made as a first job on the Tormach 440. I hand coded the G Code to run a dentistry burr in the chuck to profile the pcb tracking. OK it was a simple job but it gave me some confidence on how to make the mill sing to my tune.
The finished assembly was then connected in line with the scale lead and close to the scale. For consistency I modified all three scales in this way.
I needed a 5V feed at the display end and to achieve this I cut the display positive lead from the pcb connectors and connected them with a flying lead to the 7805 on board 5V regulator.
On power up the scales all worked well with no obvious jitter and my Myford Super 7 now has a nice readout facility.