Quornish

[shipto]

230V dc 150W motor out of a clark mini lathe. The origional controller went pop a long time ago and at that time I couldn't afford to replace it.

[awemawson]

Pop it in the airing cupboard for a few days to dry it out. If that doesn’t work passing dc through the windings of a few tens of watts to warm it from within usually works a charm v

[shipto]

I dont think its anything to do with moisture Andrew.
I looked at it after work and I think I have figured it out. First of all I stripped it apart and checked for shorts and found non but changed the bearings while it was apart. After that I ran it back up with the meter attached and noticed the voltage builds up over time rather than just being there from switch on, so my conclusion is that it is building up static. This will of course be solved by earthing the machine.

[vtsteam]

Static buildup. Never heard of that! But there's huge amount I haven't heard of. Mostly everything, actually.

Maybe that would explain the death of the controller in past lathe days.

[shipto]

There are a few articles on the subject and I had never thought about it before but some of the fans we build at work have earthing bosses welded to the frame for certain environments these tend to have some black plastic lines welded to the plastic impellers too because the black plastic contains carbon which forms a conductor to take the static away. I believe its part of the ATEX requirements.

[RussellT]

I'm surprised that you could measure the voltage if it's static build up, static is normally very high voltages but tiny charge or current.  I think the danger from static is normally sparks in flammable environments.

I wonder if your speed controller negative is drifting away from neutral?

Be careful 

Russell

[shipto]

I'm surprised that you could measure the voltage if it's static build up, static is normally very high voltages but tiny charge or current.  I think the danger from static is normally sparks in flammable environments.

I wonder if your speed controller negative is drifting away from neutral?

Be careful 

Russell

I am not 100% certain but as the only connections are going to the motor and I have tested that there is nothing connected to the body in any way its the only thing that made any sense to me. If there was a fault in the controller the power should still not get to the body I think but it wont hurt to earth it either way.

[vtsteam]

My understanding (maybe faulty, itself!) -- these solid state DC power supplies can (if faulty) pass through line voltage, unlike the old transformer/bridge rectifier/capacitor DC types which isolated the output.

[shipto]

This is the next bit which apart from holding lathe tools etc will hopefully help me make the accurate 40 degree taper in the end of the spindle.

[shipto]

Its a bit difficult getting a decent picture but that seems ok. I guess the next thing is to make an arbor and make sure, if its not far away I can lap it I think.

[vtsteam]

Interesting way you made that taper, Dwayne.

[shipto]

Interesting way you made that taper, Dwayne.

I just guessed it would be the most accurate way I could create it. made me realise that it could also be used to make micro parts if I add a tiny chuck.

[shipto]

I have made the first arbor and mounted the wheel with middling success. I think for future arbors I will leave them slightly oversize and finish them on the grinder.
Of course I had to have a little play and sharpened a few endmills which look good but I havent tried to use them yet but I also had a go at sharpening a countersink which cut really nicely but looking at the picture it seems to be rubbing at the back slightly so I guess the angle was wrong but this will come with practice.
The wheel I brought is 100mm and I think its a little too much for the motor so I will look into getting a smaller wheel or maybe a stronger motor if I can get one with the same form factor.

[vtsteam]

Great day, Dwayne, cutting your first tools with a tool you built for the job! 

[Sea.dog]

I've not had any experience sharpening milling cutters, but surely the cutting edge should be a thin parallel strip, rather than the broad, triangular feature that you have achieved?

[shipto]

I've not had any experience sharpening milling cutters, but surely the cutting edge should be a thin parallel strip, rather than the broad, triangular feature that you have achieved?

The picture shows a countersink bit not a milling cutter and a cheap one at that. However yes there should not be as much sharpened but that was me playing about and not really putting much thought into it. Hopefully perfection will come with experience of using the grinder but I wouldn't put money on it.

[vtsteam]

Better looking than my current crop of countersinks! 

A long while back I got a set of those one hole countersinks. I think they were made out of lead. Instantly on use they lost all edge and wore a groove in themselves. I have a 5 flute countersink that loves to chatter and produce razor sharp metal shards that embed in fingers, as well as produce a countersink angle that fits no flathead screw ever produced. Clearly, countersinking is an art I have never mastered.

[shipto]

Better looking than my current crop of countersinks! 

A long while back I got a set of those one hole countersinks. I think they were made out of lead. Instantly on use they lost all edge and wore a groove in themselves. I have a 5 flute countersink that loves to chatter and produce razor sharp metal shards that embed in fingers, as well as produce a countersink angle that fits no flathead screw ever produced. Clearly, countersinking is an art I have never mastered.

I was given one of those 1 hole cutters to try even on the pillar drill they suck.

[shipto]

In a shocking turn of events (for me anyway) I managed to find time to dismantle it and paint it. Not a good match but I'm not that worried.
Still have a few things to do including some guards for the wheel and drive belt, replace those cap head adjusting screws with something better and make arbors for the various wheels I have which will work on this. You might notice a got the 80mm wheels to replace the 100mm one but also brought a regular 80mm cup wheel and have a few wheels from a small grinder I brought from aldi a while ago which was terrible but the wheels should do.

[tom osselton]

Still it looks good nice job.

[shipto]

Wheel guard done the expensive way (if I was buying the stuff that is) meaning that I had a scrap of 100mm aluminium block and turned it from that. It had been lying around for ages looking for a job so I thought why not.
May have to shorten it a little but cant think why at the moment I am pretty sure that as it can rotate I can avoid it causing any problems.

[vtsteam]

That looks good! 

[shipto]

Not the best looking guard but its all I could do with the tools available so it will have to do for now. I will look at it again at a later date and try for better for now however apart from arbors for the various wheels it is done. There are many attachments I plan to add to it and will update this thread as I make them.