I wanted a starwheel tailstock for a long time – and finally got one on a company liquidation. It was not in a good shape, but I like a lot to refurbish this kind of tools.
The toolchanger is mounted on a W20-collet and had some problems: it was sloppy and had some broken parts (which I don’t know how they are named officially).
It’s the part where the tool/toolholder is clamped. The clamping force is obtained by thightening the screw on the top of the part. Two of those screws had ruined threads, one was broken off completely! I think this happened to somebody, who didn’t know about the function of this clamp – but I have to admit, that I’ve also never seen this kind of clamping by pushing a rod upwards…
After disassembling and cleaning the whole tool, the same old steps again: sanding off the old paint, priming, filling, sanding and painting again. This time without the indulgence of a sandblaster (really a lot of handwork).
The chipguard on the lathe was never installed. Not because it wouldn’t be great to use – simply because you couldn’t see through 🙂 The mounting is fast and easy and can be set to the appropriate height or lenght (and tilt too). So it would be great to use this again…
I looked at different solutions and even thought about bending one. But this would really top my skills. Searching on the net, I finally found one which fits the present mounting.
Simple but convenient – tool organisation for the tripan toolholders! This is what it looks like at the end of the day…
The layout is set «by eye». After some weeks using it, I would change this and give some more space for «overlength» tools. Luckily some pins were used to fix the bent parts! This gets handy if you rework the layout – just change the pins.
Don’t remember where I have found this one, but I liked the idea:
The blade needs to be «bent» in place mainly on two points (on the top right, and the opposite left). The concept of displacing the bearings in accordant way could preserve them a little bit. And given that this is a short task on the lathe…
The idea of easing up the setup of the blade alignment is really delightful. I saw this or similar mods on different places – the one I took a in depth look onto was on the ToolsandMods website.
Mine consist of two setscrews on each side of the blade guides – this way it’s possible not only to tilt the blade, but also to displace sideways the whole block. This way it’s really easy and accurate to set the blade in two angles: in the cutting direction and also in the cutting angle of the piece beeing cut.
The parts were milled about 5.5 mm down on the sides – making space for some M5-threads and offering contact points for the setscrews. Setting this part back, some clearance for the height limiting wheel is needed. I took about 3 mm – you can see this recess in the middle of the part.
I used some vee blocks to clamp the angled parts down. Don’t worry: those angles are far away from 45°, but this doesn’t matter to the later purpose. The other parts were clamped on the precision tool vice using a ball and some brass shim stock (similar setup as you probably would use to square up stock).
Beneath the usual mess with cast iron, it turned out well. This mod is really a great simplification of the setup process. It speeds it up and makes it really more precise. I really recommend this one!
First step: checking out, if the wheel fits the lathe 😛 This bandsaw did a great job for about two years now, and if the wheels couldn’t be trued up on the lathe, I would have kept the things as they were. As you see on the image, it worked!
Measuring the upper and lower wheels resulted in a light offset of the whole surface. Not that much, but as the wheel was on the lathe, this was a short thing to fix.
Inside the gearbox, everything looked nice: no worn gears, just a tiny amount of play. I did open this already as I received the machine. Yep, with the whole mess of oil pouring out – so if you didn’t open it yet, be prepared and have some rags on hand.
Probably this was the cause of screwing this lid that much down, that I completely thinned the gasket. Well then: a new gasket with some scrap 1 mm rubber plate is done fast – and don’t forget not to overthighten the lid. I need to confess not beeing aware of the different oils and lubrication possibilities – I believe what’s indicated on the label. So far, it worked for me…
As I got some scrap rubber of cutting the gasket, I laid some underneath the junctions of the sheet metal box containing the belt and the pulley gears and the top of the cast iron arm. This really reduced the noise of this resonance box!
The power drawbar is a great add-on for the PCNC440. It eases the toolchange – which can get quite annoying the conventional way, after opening the spindle door, release the drawbar, …, tighten the drawbar and closing the case for the umpteenth time!
Yes, it’s a timesaver! But in my view, it has one drawback: the pneumatic push-button occupies one hand. And for a toolchange it’s really «handy» to have both hands available.
A foot pedal switch is a great idea. Even though there are pneumatic foot pedal switches, I didn’t wanted to hassle with long air pipes. A wire based electrical foot pedal switch is really easier to use – and to install too! The more so as there’s one in the shop I saved for later use – very simple, but sturdy, used on a punch press for years.
The bigger Tormach machines (like the PCNC770 or PCNC1100) have an electronic control circuitry for the power drawbar. Unfortunately the PCNC440 misses this option, but the needed information is on the net or can be seen on the pneumatic push-button:
2 positions Air Valve
the machine has a 48VDC- or 24VDC-output integrated (for the solenoid)
The solenoid air valve I found was an «Airtac 4V210». All in all about 20 bucks, some silencers and connectors included. Yet, the filter regulator lubricator (FRL) was set up later on – another 25 bucks investet in persistence…
The implementation was easy. The 24VDC-output (used for the water pump relais) has of course also the right values for a solenoid. The foot pedal switch was simply clipped in between.
The connector was placed between the 5-pin-connector of the height gauge/passive touch probe and the probably future expansion slot of the 4th-Axis. The toughness of the body housing is impressive by the way!
Besides of the power drawbar being really «handy», the footpedal activation is really fast and comfortable. You can remove the actual and insert the next tool within seconds – really a big timesaver.
Open issue and warning
Even though the footpedal is only «primed» if the machine is powered – it’s always active while it’s powered! This means, that a misstep while the spindle is turning could be fatal and dangerous. Please take precautions if you think about making such a mod – everybody is responsible for it’s own and the health of others around!
I need to dig deeper in the controller scheme – I’m quite sure, that there’s a possibility to deactivate the solenoid, while the spindle is turning…