It would actually be easier to use (mild) steel, but much heavier and also it would rust/tarnish and not have the right appearance. I've used aluminium for most parts and stainless steel for some functional parts that need to be stronger. If I were to build a T-600 I would build it all from steel and blacken it. (Maybe one day)

It is! The problem is it needs a specific cutter for each number of teeth, and the geometry is much more complicated. A shaping cutter (which looks very similar) will cut any number of teeth, like a hob.

Sounds like the spindle bearings need adjustment? If you remove the spindle (it will drop out of the bottom if you remove the quill feed shaft) there should be a nut at the top to preload the bearings. Drain the oil first and tilt the head on its side.

@@AndysMachines Many thanks for replying. The Quill feed shaft? Is that the large rotating handle on the RHS? Your saying to remove that assembly and the spindle will drop out? Sorry but I've never done anything like this and it's my 1st Milling machine and I'm an old bloke. LOL

@@AndysMachines I'm just thinking, if the spindle was loose, wouldn't it move if I tried to move it, by hand, without having the machine in operation? I've done that and I am not able to feel or see any movement at all and I'm using all the strength I have. No movement either laterally or vertically. I am not a serious engineer but I am mystified. Overall, I tend to agree with you regarding the spindle bearings not having the correct tension but is there anything else you can think of that might be causing my issue? Anything to do with the quill perhaps?

Have you tried putting a dial indicator on it? Attach it to the table and put the plunger/stylus on a tool in the spindle. Pushing against the quill/toolholder you should be able to deflect it a small amount but it should spring back to where it was. Try also pushing on the table instead. If it's not the spindle bearings it might be the table gib strips. Note that there will be some backlash in the screws so try locking the X axis and see if you can move the table lengthwise, then try with the Y (only) locked pushing front to back. To get the spindle out (from memory) you need to remove the clockspring on the left hand side, then I think if you remove the fine feed wheel/housing and unscrew the clutch handwheel in the centre of the 3 quill levers, then the whole shaft will slide out allowing the spindle/quill to drop out of the bottom. LOCK the quill first! So that it doesn't fall. To actually remove it you will probably have to tilt the head on it's side, you may want to drain the oil first (though in fact I think it shouldn't run out through the spindle if the seals are good).

Thanks! Time spent cutting (per gear) is probably the least. Setting up is really just like tramming a vice, though I may have to do both the hobbing attachment and the mill head. Planning and preparing the blanks etc. can vary wildly though often it's just some simple arithmetic in my head and turning a piece of bar on the lathe.

That's probably an imperial 20 DP gear which would be 1.27mod. The closest standard metric sizes would be 1.25 or 1.5 mod.

I get this question a lot and it does seem like a quick and easy solution to put a stepper motor on a dividing head/rotary table, but due to the high gear reduction it's usually not a good idea unless you are cutting gears with very large numbers of teeth (like hundreds). To avoid swamping the arduino you'd have to run the mill spindle no faster than 480rpm (60x80Khz/2500x4). But don't forget that also the stepper is going to have to turn 50x faster than the gear blank which is likely to be the limiting factor especially for gears with less than around 30 teeth, most stepper motors have very little torque over 1000rpm. For something like a 10 tooth gear you'd probably have to run the milling machine at less than 100rpm and feed extremely slowly.

@@AndysMachines Thanks a lot, for your reply! I see this is not Ideal, but as I am planning of making just one offs I may give it a try anyways and just cut very slowly.

Yes, 0.01mm is plenty accurate enough for anything but the tiniest gears (that's less than half a thou for non-metric types). Whether you choose to use a gear cutter or a slitting saw really depends on what works best for your application.

Thanks, but I'm really no expert at all of those things! I've learnt just enough from each to be able to do the things I want to do, mostly self taught apart from a couple of college courses. It used to be called 'a Jack of all trades' but I believe the modern term is 'agile'. Whilst a little knowledge can sometimes be a dangerous thing, I often see projects built by people with far better (say) computing/mathematical skills than me, but then the whole thing is let down because they've used some crappy 3D printed part, whereas if they could just do a little welding or machining, even at a very basic level, it would have been much better.

It did stop it completely for a while, but now it seems to have come back. I used to have 2 or three drips of oil on the table every morning, now I get maybe 1 per week.

@@AndysMachines Andy, I noticed that the seals seem to be drying out (marks on the drive gear) after sitting for a while then when you turn it on, I think it tears it a bit. I thought I would put some Teflon grease between them to keep them lubed. Rich

Does it stay in sync when not actually cutting, just rotating freely? If it only goes out of sync when cutting it's probably due to the gear hob not being tilted to the correct angle and having a tendency to drive the blank like a wormwheel. If it loses sync all the time consistently check that you have all the ratios correct. If it seems more random that could be an electrical problem/noise. Some encoders do need pullups on the A/B outputs, but if so I'd expect it not to work at all without them.

Thanks for your comment - indeed 2.2 kOhm resistors seem to do the trick! More testing needed, but at least the results appear to be a gear already! I use a cheap optical rotary encoder from CN, but it works perfect!

That's correct. Other parts of the skull were also from a Tamiya RC car and other model kits.

I had to go back and look at the video to see which driver I used! This exact driver is no longer made, the nearest replacement would be this: motioncontrolproducts.com/dm432c-stepper-drive.html However any step/direction controller that has a current rating suitable for the motor you are using will work and there are many cheaper options available eg. if you search for 'DM542' on Amazon this is a good all round drive, you'll see the same type offered for wildly varying prices (like 6x). Avoid the dirt cheap ones but don't pay over the odds, here is a reasonably priced one: amzn.to/3WdK0OH

Dividing plates with arms are useful for indexing each tooth, but you'll probably want to use the angle readout directly on the dividing head for the starting angle for each cut, then reposition the arms so you can index around to cut each tooth.

Most saw bars have a hole here, I think the intended use is for hanging up the bar on a nail to store it. You can store it this way with the chain still attached and it doesn't get tangled. (I actually hang this whole tiny saw on a nail this way). On bigger bars you can also use this hole to attach things such as sawmill/planking attachments. In the past I've also drilled extra holes at the other end of the bar as well to fit a sawmill attachment. The bar is hardened steel and you can't drill it with a regular drill bit, you have to use carbide.

Unfortunately I don't have an accurate way to measure the very short high current pulses, but yes I imagine it's in the many tens or even a hundred or so amps.

I didn't actually make any prints for this, I just built it mostly with what materials I had to hand as that was quicker. The only parameter that was important for me was to make the centre height match a tailstock I already had.

The circuit diagram and explanation is in part 2 of the video. I used quite a basic circuit, there are more sophisticated ways to do it.