Member postings for Colin LLoyd

Thanks Stephen - you have evidently solved your problem. I just used an external RPM sensor instead - although I would like to fix mine properly. Your reply has probably prompted me to have another go. For future reference - the Amadeal CJ18a mini-lathe shares many attributes with the Grizzly-Go765 lathe and even the Warco WM180 appears to have the same control board. Some information regarding the control board can be found here: **LINK**

Adrian - no patience me - just hand-held against grinder and rotated. Used my drill size guide as a template to see how I was getting on and when I had arrived. It will never win awards - but it works. Thanks.

Adrian - thanks. I can set up a solid rest support against my bench grinder and take your advice.

Now the next problem. The chuck key looks case hardened and initial attempts to machine it with carbide inserts seems to confirm that (although I'm no expert - let's cut to the chase and confirm that I am actually a novice). Because of the less than ideal way of holding the chuck key in my independent 4 Jaw chuck - I've just been attempting very shallow passes along the pin - and not much seems to be happening except a lot of squealing from the interaction. Probably because carbide inserts are meant to be worked harder than I'm doing. Filing the rotating pin doesn't seem to do much either. Have thought about a Dremel with grindstone attachment held securely with a novel clamp in the toolpost being run counter-clockwise to the rotating pin - but it's all getting a bit Heath Robinson'ish. Any other suggestions or replies to the following questions gratefully accepted.

1) Are chuck keys case-hardened and to what depth?

2) What steel are chuck keys generally made from? - important for the next possible step

3) Do I try and and Anneal the pin and quench slowly in sand and then machine?

Just to update - a 16mm 8mm pin chuck key is winging itself to me as I speak - and once arrived it goes into the 4 jaw independent chuck on the lathe and I follow Howard's advice and turn it down to 6.5mm.

Thanks Howard - I have just looked at my other chuck keys and one that came with a B16 3-16mm SAN OU does have the correct tooth spacing but has an 8mm pin. Perhaps I'll go and get a 16mm chuck key and as you say turn it down.

I've just sent an email to EXCEL Machine Tools in Coventry who, according to the Model Plate originally supplied the machine in 1986 to see if they can supply said chuck key.

And thanks to DC31k for all those website addresses - will investigate.

Recently been given a Pinnacle PD-10 bench drill but without a chuck key. It has a 13mm chuck labelled "Select Capo JT-6 13mm". The unusual thing is that the 13mm chuck keys I have or have bought online do not fit.

The chuck itself apart from the description above is 46mm in diameter with 30 teeth and a 6.5mm Pin (Pilot Shank).

Anyone know where I can source a replacement chuck key? Very few online sources describe anything other than the chuck size i.e in my case 13mm. I've already bought one online that didn't fit - so don't want to try this scattergun approach again.

Alan Wood - thanks for the offer - but I've ordered some breakout boards with KY-003 chips on board.

Duncan Webster - grateful for the code - that's save me some time. Will run it as is to begin - together with an independent RPM meter to see what I need to take out/amend for my particular use.

To everyone else - thanks for the input. My Display modules and Nano boards have arrived - together with the KY-003 breakout boards. Now to put it all together and see what happens. I will let you know.

In the latest MEW (June 2020) Duncan Webster uses a UGN-3040U Hall effect switch on the end of an Arduino Nano circuit to make a tacho. These switches don't appear to be available from any place I've tried, Ebay, Amazon, CPC-Farnell. These switches (from their datasheet) are 4.5 to 24V operation, are capable of fast repetition rate and are useful in applications requiring relatively large distances between magnet and switch.

Does anybody know a suitable equivalent Hall effect switch to take the place of the UGN-3040U - or alternatively where I might find these switches online.

Sorry - should have added - it's a pdf coy of the manual.

Hi Richard, I don't have my Chester Mini-Multi any more but I do have the Manual for it - if someone can tell me how I can attach it to a posting - Neil?

Hi Guys - sorry about silence - but a few other jobs have got in the way. I tried to supply 5v to the Digital display - but without success - perhaps the digital display board itself is the culprit. In the meantime I have added a magnetic proximity unit to the gear cover with a small rare-earth magnet on one of the vanes of the rotor. This seems to work fine - although it does mean another wall plug for the supply. I will continue to investigate - but the immediate problem i.e. not having a digital RPM meter has gone away.

Stuart - one of the first jobs I did was to exchange the bearings for angular contact bearings - although I was advised (too late) to actually install taper bearings. I also did an experiment on the effect of pre-loading on the temperature increase in the bearing housing - see the following

https://www.model-engineer.co.uk/forums/postings.asp?th=130430

Thanks Guys for all the input. You will have to be a bit patient as I go through all these useful ideas and suggestions. While no electronic engineer - I know how to use DVM and oscilloscope (although I only have a PC operated HANTEK). I will let you know of my findings.

Steviegtr - that's exactly what I plan to do - but unsure of which of the 4 wires going from the Circuit board to the Digital Readout are the +5v and Gnd lines - I don't want to blow the entire control board by getting this wrong. From my initial post - it looks like wire 2 is +ve and either 1 or 3 is Gnd - but not sure. Failing everything else - I've found a youtube video that shows how to put a hall effect sensor chip (of which I have several) and a rare-earth magnet onto the timing belt lower pulley. There again I could do the same onto the spindle behind the chuck - and link up to external Digital Readout unit as I have done for my milling machine.

Thanks for all the replies. I've discovered that my machine appears to be an exact copy of the Grizzly Model G0765 - for which I've gained a comprehensive 76 page manual.

Specific reply - not sure if John and Martin are talking to me or to each other - so will leave that for now

Steviegtr - not sure if LED or proximity speed sensor. The sensor comprises 2 cube shaped columns either side of a multi-finned disc on the mandrel end as shown in the attached photo The columns do have a thin recessed line halfway down - which could contain a small LED on one side and a detector on the other.

Hi Steve, thanks for the information and the circuit diagram . Your comment about the first 2 connections being the + & - makes sense as I was getting 1.2v between the 2nd and 3rd and same between 1st and 2nd - which means that the 2nd connection is probably positive. I will check R3 as well. Thanks again - will keep this thread informed until conclusion.

I have a Real Bull Mini Lathe as supplied by Amadeal Ltd of London. The in-built RPM display suddenly stopped working. By which I mean that the display stopped working (no LEDS light) - not necessarily that the sensor wasn't working. Taking the control box off and also looking at the sensor in the gearbox end of the lathe showed no visible reasons for non- operation i.e. severed cables, burnt areas of the control board. All the rest of the lathe functions as normal. Amadeal as always were very helpful, but admitted that they were not electronics experts - but suggested possibly the 5v feed to the display was at fault. And it's true that no combination of the 4 contacts on the control board supplying the display gave anything above 1.2v. The RPM display is a useful item - but not to the extent of buying a new control board. I could just provide an external 5v supply to the display - but without knowing which of the 4 pins provides power - this might do more harm than good. Alternatively I could just add an external Hall effect RPM meter to the lathe - sonething that I have already done to both my Amadeal Milling machine and my Woodworking lathe. Does anybody know the circuit diagram for the control board of these types of lathe - or at least the functional pin-out of the RPM display cable.

Thanks to everyone - the drill out with a slot drill to ease the strain on the lathe is good idea. I will also investigate the archives and follow up Michael Cox and JasonB suggestions.

I think this is all I need to know to start to practice keyway cutting - thanks to everyone again. Will suggest that my input to this thread is now answered.

Thanks Paul - even at that price (and it is higher in the UK) it's still greater than I would like to pay for something that I might never use. However, the ability to grind my own HSS tool to suit - if the need arises - appeals to me. And as I have both lathe and milling machine - the machining aspects are not difficult. I just need some idea of cutting angles for the HSS tool. I could even regrind a parting tool to provide the pushed cutting edge - after all the video shows the tool acting just like a wood plane does. It may take longer than broaches - but I have the time and the items I envisage I might need to keyway will be small and one-offs.

I'm interested in general regarding cutting internal keyways, but not sufficient to buy a set of broaches for my occasional use. But I saw this video ( https://www.youtube.com/watch?v=XcU0LTavzDM ) where a single cutter held in a lathe toolpost is fed into the component held in a stationary lathe chuck, with the cross-slide and saddle being used to make the lengthwise and depth cutting. I'm guessing this is what IanT alluded to above. IanT also alluded to DIY designs for this tool - does anybody have diagrams for such a tool?