Member postings for jon hill 3

In a previous unrelated post another member commented on the technical difficulty of achieving the adjustment mechanism. As I have been working on the same project and also had difficulty understanding the instructions, perhaps some more experienced members could explain the cuts necessary.

Perhaps where I am going wrong is I don't fully understand engineering drawings.. One of the many topics I need to get a hold on.

Anyway back to the topic from my understanding from the drawing on page 19 'Lathework a complete coarse' it seems that a vertical slot of 2mm is cut into the base. This doesn't make any sense to me as I cannot see why the base would need to flex in this area. Also he mentions the v grove around the circumference disguising a cut or cuts. I am left unclear as to where the cut or cuts should be placed. For instance should it be where the clamping screw goes or adding a 2nd parallel cut on the offside to create a hinge effect or could you use a parting off tool to remove a few mms all round?

Pics of project so far including failed attempt at milled 'nurling'. I tried to get a bit amitious instead of hand filing I set up a rotory table I had not used before on the milling machine. The work wasnt sufficiently clamped and the cutter wondered, oh well back to the mark 2 attempt.

Hi Geoff

Let me get this straight the swarf tray screws into a couple of t nuts, which are themselves held in the slots by grub screws.....

Like the leadscrew cover, perhaps a famous brand of stout might be more to my liking.

Just a thought, might it be an old policemans telephone box. I was led to believe that before the days of 2 way hand held radios or mobiles, there were telephone cabinets similar to this....

Anyone got any neat tricks to prevent swarf damaging the ways, getting under the apron, abrading the leadscrew etc?

I tend to clean down the lathe or milling machine after each use but there is always the risk of chips getting into places you don't want them.

My ways on the speed 10 are quite scratched and I suspect that there is a lot of swarf accumulation under the apron.

Panic over I located a spare key, I might try some of the lock pick options just for fun in case I mislay the key again.

The wiring to the switch is consealed by another panel in the lathe cupboard, so I think I will leave replacing it for now.

Thanks for everyones advice.

Jon

Hi Ega

The change wheels can be accessed ok at the mo. I have also found that I can fit the drawbar through the front of the mandril, although its a pain in the arse to put in and take out.

I made a slide hammer to extract the flycutter using a similar setup to how you would remove diesel injectors. However I am not sure I would want to use the slide hammer on a hard centre.

Being a bit of a cheapskate and not wanting to buy lefthand insert tool holders,I wondered would it work if the flipside was machined to make the holder universal?

My existing brand insert diamond shaped carbide tool holder does not appear to have any relief angles on the holder.

Thanks Michael will look into the locksmith option.

If anyone is any good a picking these locks or has another crafty solution let me know....

I was using the lathe and accidently hit the emergency stop button.

No problem you say just twist to reset, however this is an old school lockable mushroom and I have mislayed the key!!!!

Are there any budding locksmiths or reformed characters who know how to pick this type of lock?

Thanks guys all useful tips, currently I just use a dti on say round bar.

I think I will make a new 2nd key as my next mini project.

Hi Nick

Thanks for the feedback.

Just a few more questions, should the paper be bonded to the disk and does this dampen vibration and normal stress to the wheel?

I am having great difficulty centering an independent 4 jaw chuck does anyone have any quick or fool proof methods?

Hi Paul

The morse taper flycutter does have a tapped hole to for a draw bar to go through the spindle, however the lathe is positioned very tightly in the corner with not enough wall space to put a draw bar from the back. It may be possible to fit the draw bar first through the front.

I shall have to give this a try, the alternative of repositioning the lathe doesn't sound very appealing. I still havent got round to checking the level of the lathe or turning test bars.

Pics of the coarse and fine disks for identification if anyone knows what type they are?

Just to add some further detail its a kef motor grinder. Its had faily constant use, bolted down to a steel bench and has no vibration issues except on startup and de-celeration and even then its not that noticeable.

The course and fine disks fitted are a blue composite that looks similar to carborundrum.

I will add a picture later.

Edited By jon hill 3 on 01/09/2020 10:47:22

I have been putting my myford through its paces recently with some test exercises from one of H. Halls workshop practice series.

For those interested I am making a small marking gauge out of mild steel.

I was thinking of the most practical way of milling a flat on a round shaft, so I choose using the flycutter. This was purely for simplicity sake as I am using the qc toolpost to hold the work.

However I cant fit a draw bar to the back of the Morse taper to hold it in tight, does this present any safety concerns? eg the Morse taper flying out of the spindle...

So far I am only taking light cuts of 10 thou.

I have an old bench tool grinder, 400w, 3000rpm, 150mm which is approximatly 40yrs old. However to the best of my knowledge the carborundrum disks have never been changed or ping tested since fitted. They have been regularly surface dressed and have not been abused, ie edges are reasonable straight, no noticable uneven wear or dents.

Should I be worried, or take further safety measures?

I have machined up a backplate for a new chuck and need some long 6mm threaded rod to hold a chuck down to the mill table.

The thought occured to me that I might need something a bit harder that what I can easily get from b&q.....

Any ideas on hardness spec, or could I heat treat some zinc plated rod?

Thanks everyone for all your research, I did eventually find a US chart that lists the exact dimensions of er collets. Previously I thought it might be er20, however another site had a table which suggested it was er16.

Having done some measurements from one of the genuine proxxon collets they are as follows: 4 Deg taper, 27.06mm height, 18.24mm diameter (widest point). However as others have said it is a non standard size and not an 'er' collet.

I will leave the chart for reference: **LINK**