Member postings for Nicholas Hill

Hello,

I am very much an amateur who seems out of their depth!

I have recently renovated an old Mill, and when I tried to use it on steel, I can't seem to get anywhere.

I tried with a inch block of brass, and it cut through fine. I tried a 3 inch piece of chemiwood and again it worked fine. But, when I tried EN3....I get an awful noise, and the cutter jams.

I have tried all the speeds, I have tried the cutter going clockwise and anti-clockwise, I have tried a 6inch slitting saw, a more substantial 4 inch cutter...

At one point I was getting sparks out!!

The machine itself seems in good order, I measured the bed to the arbour, and it seems to be parallel.

Its an Ajax AJ8, so I assumed could go up to an 8 inch slitting saw, but if it struggles with a 6 inch saw and a 4 inch cutter. What sizes should I be thinking about?

Any suggestions welcome. The cutters are second hand, but seem sharp, so I don't want to be a bad workman blaming his tools. But my head is getting raw with the scratching going on.

Photos attached are of the set up and a close up of the 'results' of the 4 inch cutter, note the 'stepped' appearance where the cutter jammed.

Nothing works.

PS sorry for the upside down photo...It appears normal in my gallery..but is inverted by the Forum..Even if I load it rotated 180deg...But its a fairly self explanatory.

Many thanks,

Nicholas

Edited By JasonB on 12/09/2022 18:43:19

Hello,

I recently purchased a semi-complete Quorn tool grinder. I was surprised at how cheap it was, until I got it home and inspected it. All the other parts are there and in good condition, apart from the workhead. Which as can be seen by the photo is not according to the drawing!

Can anyone suggest why it would be made with out the support for the Workhead?

Any suggestions on how to correct the part? I am tempted to make a new part out of a machined round bar? As in mill out the right angle support, to almost replicate the original casting, and then follow the instruction from there.

But I am naive, so any suggestions most welcome. I have a Myford lathe with a Rodney, and a recently refurbished horizontal mill, so machine work isn't an issue.

Many thanks,

Nicholas Hill

Hello, its me and my Ajax again...

I am trying to remove the arbour, but I can't seem to work out how.

I believe there is a draw bar, but I can't seem to see any access.

The end of the arbour appears to be a machining mark, while the pulley nut, had a pin that was soldered over. I tried numerous times to undo it before trying heat to loosen it. It was then I discovered the pin. The inner boss of the arbour has a hole in, that indicated a bar should be used to unscrew something?

Am I missing something? If I try anymore force on the nut of the pulley wheel, with a bar in the arbour boss, I fear twisting of breaking the overhanging support.

I assume it is a standard fixing?

Many thanks,

Nicholas

Many thanks for all the info.

Overnight I ordered Brian Wood's book on Gearing of Lathes, and it seems the people calling it a Worm are quite correct.

I had never heard of Diametral Pitches before. But after looking into them, it works out almost exact. The larger gear wheel has 66 teeth and is 4.1 inch in diameter, giving a DP of 16.1.

A DP 16 has a pitch of 0.196 inch giving the 5TPI I measured!

I have been pondering the idea of using an insert, there is a good 1/2 inch on the collar, and as has been mentioned it is only a handle, so no force will be exerted apart from me turning it.

I do get the idea, that one should keep within their limitations, but I am more of the camp that nothing is impossible. I recently upgraded my Myford to a power cross-slide. Something I expected to be a days job, ended up being a week. But one learns so much more from failures. such as NEVER reuse high tensile bolts...their heads can shear off...but hey, I had to learn how to remove them.

In this case, I think I will go for the insert, when even the books warn of worms being special cases, yet I can't seem to find out why they are different from standard screws.

Many thanks for all the advice and help. It all goes in the memory bank, so although not used this time, will most certainly be of use in the future.

I still need to make a jib strip (for the knee) and the brass end piece that the handle goes through. I do have a spare Myford Lead Screw handle, so might swap that in, as I can vary the diameter of any insert I put in to match the brass end piece.

After it is up and running....its time to see if I can add a vertical milling head.

Anyway, thanks again, Nick

Edited By Nicholas Hill on 13/07/2022 21:46:26

Thanks for the replies.

To add more details, I have added a photo of the whole mill, and a close up of the large gear wheel tooth.

The part I am replacing is the feed screw for the table. The Mill was dropped in transit, and the handle broke off. I've had it for a few years, and have been putting off repairing it. But needed a circular saw this week, and so it prompted me to look again.

So, the consensus seems to be it is an Acme, but use the existing thread form as a guide. How accurate does the grind have to be for the tool? If it is a Acme thread, then should it be 29 deg? Would that be two angles of 14.5deg? I can't imagine my freehand grinding would be accurate enough, hence the thoughts of using the lathe.

I can set the tool post to the correct angle, and with the grinding wheel in the chuck, get pretty close. But will this damage the lathe?

Do I need to think of anything special regarding the cutting tool? With the depth of the cut, and the the narrowness of the blade, I fear broken cutters all over the place. Parting blades are notorious for breaking, well at least with me! What speed should I run at? Is it better to go fast or slow? Does it need coolant?

Anyway, many thanks for the guidance.

Nick

Edited By Nicholas Hill on 13/07/2022 01:29:22

Hello, I am getting very confused by square threads.

I need to make a feed screw for my Milling Machine, and can't identify what type it is.

It seems too deep for an Acme thread, and too sloped for a square thread.

The dimensions I have are;

Outer diameter = 5/8

Inner Diameter = 3/8

TPI = 5.

The best I can measure the thread, it is approx 0.08in wide with a gap between threads of 0.12in to make up to the 0.2in for 5 TPI.

According to wikipedia, an Acme thread of 5/8 should have 8TPI.

So is it a wide Acme thread? Or a square cut one?

If an Acme thread, do I need to grind a cutter to the correct 29 deg angle? I have a Myford and a grinding wheel, so can this be done using the top slide? So the angles are precise?

Or any other clues would be most helpful. I last cut a thread about 20 years ago in a college workshop...

Many thanks in advance, and sorry if the description is a bit garbled. Threads still confuse me. Every bolt I come to is always a trial and error..is it a Whitworth, a BA, a metric, a AF....So Acmes, Square threads, Trapeziodal threads....,

Many thanks for the replies.

I appreciate its a bit of a hammer to crack an egg, but I guess the idea was to try milling curves, and as it was in wood, it seemed an ideal trial piece. But..in the three hours or so spent on it...it is not the best choice! So...although this is a very simple example, it is kind of like me learning to tie my laces, before becoming a marathon runner.

After reading the other replies...I am now more confused than ever..So have tried to sketch things out.

I get that the diameter of the cutter is larger than the scribing point..but surely they would have the same centre? So although it wouldn’t be the correct size, it would surely still be parallel? As in it would make a 7/8 inch diameter instead of a 1 inch? I am lining up the diameter to be cut by eye, to the outside diameter of the cutter. The scribing point was purely to ensure things lined up.

Again on the vertical slide, as you offset, that surely just changes the diameter? So if when central everything lines up, if you lower it by an inch, it would create inch radii’s?

My rather poor sketch..with fig 1 set up so everything is in line. Fig 2 being with the verticle slide offset. With in both cases the horizontal axis being the slides axis of rotation.

So to my sketch everything seems to work....but clearly I am wrong! And looking at the logic of the cutter diameter, that seems the answer, but I am missing a stage in the logic...

Thanks again,

Nicholas

Hello, I have been trying to mill a curved surface, and have found myself in a total pickle!

I am using a Myford with a vertical rotating slide. The concept being that by rotating the slide the curve will be milled.

But...my alignment is all wrong..and I don’t know why.

I have lined everything up with the centre of the spindle – using a scribing point in the chuck, but it keeps producing off centre curves. My only adjustment is the vertical axis of the milling slide – to change the radius.

The photos are of the latest set-up and if I trace the arc...you are talking a variance of 1/8 inch on a surface that is about ½ inch wide!

I assume it is all about geometry..but I’m baffled. If a point lines up with a centre, how can it produce off centre radius??

I am now on my 5^th attempt...and it is not improving..

Any help, would be superb...I’m tearing my hair out..am I fundamentally wrong in the set-up?

PS Its for a mould for a DH88 Comet cockpit section.

Many thanks in advance,

Nicholas

Many thanks for all the advice. My first thought was to bolt it back together, but had heard that welding was an option. But at the price quoted, I am now, based on the replies, reconsidering screwing it together.

The piece is approx 12mm thick, so based on the above post, should I only use 4mm screws, or can I go larger, as 4mm seems a bit small.

How does the strength of the joint compare to a brazed one? Would a screw and glue method be sufficient for basic hobby workshop use? Or is it more of a stop gap solution?

As for the idea of dumping it....when I was stripping it yesterday, I totally fell in love. It is beautifully made, everywhere you can see the thought and design. The knee is raised by a series of bevel gears on a threaded rod. The feed screws are secured with tapered pins, not peened pins. You only need 3 allen keys and one spanner for everything. Besides, apart from these....minor issues...it is a good honest machine.

As my previous pictures don't show the full glory, this is how it arrived yesterday.

Many thanks again, for the suggestions,

Nicholas

Hello,

I recently bought an old Ajax Horizontal Milling machine, unfortunately, the owner knocked it over while loading it...this broke the handle off the bed screw, and also, more crucially, the dovetail of the knee cracked off.

I have looked into getting it welded, but a local company is quoting £450....for about 3 inch of welding...This seems very expensive, considering the machine is only £50 (the owner gave me a hefty discount after his accident). Has anyone any suggestions of good cheap cast iron welding service? Or an alternative option? I have thought of drilling and tapping, but am not convinced there is enough material.

I have attached some pictures, to give an idea of the problem.

Many thanks in advance for any help, or suggestions,

Nicholas

Hello again,

Many thanks for all the helpful suggestions. I had not thought of the case hardening and it makes a lot of sense. As you have guessed this is my first time at milling cast, and am somewhat of a novice as regards milling. So many thanks for being kind.

Several people have suggested a Model Engineer club, and I tried looking into the Notts branch. But have yet to hear back from them, and like most clubs, they seem very Railway orientated. My field is aeroplanes and motorcycles, so am not sure if I would “fit”.

I have been at work today, so have not had an opportunity to try the ideas mentioned. Of the suggestions the consensus seems to be:

1/ The Milling Cutter requires more power and rigidity than I have, so the first thing is to try another type – I have a fly cutter, and end / slot mills, so have options.

2/ In conjunction with this, investigate the surface via a file, and if required heat treat – what temperature should one aim for? Can I use my oven?

3/ If the above has improved things, persevere with deeper cuts – I tried one, and it made such a awful noise, I stopped, but it did work.

4/ Try at a higher speed – I guessed at my speeds based on the diameter of the cutter, and an old book on Milling. But as they this was talking about slot mills, it was always a conservative speed trying to compensate for the lack of rigidity in the Rodney.

I’ve attached a couple of pictures, one showing the cutter tips. Although cheap inserts, they seem in ok condition. I thought the main difference in cost was about chip clearance?

The other picture is of the “deep” cut I tried, which although making an awful sound is okish.

Oh, on the comment about cast iron dust…It was rather hot in my shed, so I worked shirt-less, and had a very black stomach after….

Oh, thanks for not mocking my Rodney…I have cursed it numerous times, and pondered if it was a good idea, on more than one occasion…..

Many thanks again,

Nicholas

Deep Cut:

Carbide Tip:

Arrrg, I got all excited. I thought you were talking of Hawker Ospreys!

Hello all,

I am not sure if this is a Beginners question or a Manual Machine Tool one,. So please tell me to go to the Beginners if my questions are too naïve.

Today I have been trying to mill a flat cast plate, and seem to be experiencing every problem going!

I’m using a Rodney milling Attachment, so rigidity is compromised, but even the lightest cuts cause an awful racket, and noticeable vibrations. The results are poor, and time consuming to get to. So I believe I must have something fundamentally wrong.

One of the causes appears to be the rough cast finish of the plate, it seems that every time a cutter hits a peak, it causes perturbations. It makes a thwacking noise as the cutter starts engaging the plate. Once it starts over the plate, the noise reduces, but a vast amount of friction starts – smell of burnt metal, and slipping drive belts causes lead screw judder. I have always been told that cast iron needs no coolant?

One area that I also know is compromised is the clamping – with the Rodney one has about 2 ½” of working space, so a proper clamp is not possible. But I have double sided it to the cross slide, so it is has direct metal contact, and it seems securely clamped at the edges. But due to the size of the Cross Slide, there is some overhang at the front.

Options – 1/ Change feed rate or spindle speed. 2/ Use a Slot Mill instead of the Facing Mill. 3/ Improve clamping – not sure how. 4/ Buy a Myford Collets system at silly money, and hope it allows space for a proper clamp. 5/ Buy some better cutters for my Facing Mill – the current ones are cheap that came with it. 6/ Another idea???

The results and set-up are shown in the photographs attached. Spindle speed was 200 RPM, feed was 0.0069” / Rev, depth of cut was 0.0025”

Any help most appreciated.

Nicholas

Set-up

Clamping close up

Results.....

Yes, I've just contacted the Notts SMEE. I was slightly concerned by the railway focus of Model Engineering clubs. My work mainly involves high carbon steels. So shall wait for a reply, and go from there.

I've also been pondering on how to cure some of the Rodney issues. Conveniently the machine has a ground bed on the face of the vertical support pillar that contains the angle drive. So an angle plate could easily be fitted, which would brace the cantilever. It may require some damping with rubber grommets as one wouldn't want to induce vibrations from the drive shaft.

I will also investigate bushing - I am not sure there is enough wall thickness to do so? But that seems the most logical idea.

I am still not sure on the alignment issue - it has to be aligned in 3 axis, with nothing to guide! Until one discovers the optimum set-up, it is blind guessing.

Link to Rodney page on Lathes:

**LINK**

Thanks again for all the advice,

Nicholas

Hello,

Many thanks for the rapid replies. I shall read and digest Howard's reply. My first thoughts are, that I agree with the statement that the keys are not crucial to location, and the bore of the plate is more so. I can find little play at the nose end, so believe the lower bearing to be ok.

I also like the idea of joining a Model Engineering Club. I live in Beeston, in Notts, so I am sure something must be around me. It is the home of Myford after all....

Regarding my thoughts on known defects on the Rodney, there appears to be no way of ensuring it is located correctly, or anyway of adjusting for wear.

The whole alignment of the milling shaft is dictated by two hollow pins, if the alignment is out by a couple of thou, the whole thing seizes up.

As there is no bracing for the upper part, the whole rigidity is compromised.

As for attaching it to the bed, it is the lack of access that is the problem. To attach the rear foot, one has to lean the machine forward, with one hand, and try and locate a blind bolt with the other. The only way I could do this, was to rest the mill at an angle, on its spindle (quill?...I am new to Mills), on a block, while using my hands to locate and attach a nut to the bolt. But if the spindle suddenly retracts, there is a high risk of bed damage.

Overall it almost appears if the Rodney was built cheaply, and sold expensively - hence the compromises on rigidity, and accessibility. So I guess my thoughts were, that over 40 years, I assume people with vastly more knowledge than me would have found solutions to work around these compromises. The lack of a Rodney manual does not help!

Anyway, many thanks for the help and ideas.

Nicholas

Hello again,

My little vibration survey, was basically using the Physics Toolbox App on my smartphone. It rather usefully utilise the phones accelerometers, to show g (9.81m/s) in xyz axis, etc. It also has a pause feature when recording, so by placing it at various points, one can find the unusual vibrations very easily. It also highlighted that by not securing my lathe to the floor, it has a constant ambient vibration, but as it is doesn't vary across the whole lathe, it should be ok. But ideally needs sorting out, in the long term.

Nicholas.

Hello,

As part of my replacing top slide project, see other post, I have had my Rodney Milling Attachment running today.

After running a DTI on the milling chuck, it became obvious it had a 0.002" vibration going on, with a elliptical path.

After much investigation, I concluded that pulley drive was the culprit. It seems the plate and the locating teeth, are of a very loose fit. I can see the 0.002" movement at the chuck, by just moving the top of the spindle.

What is odd, is that there appears little wear, as though the loose fit is intended.

My intention is to make a replacement plate, of a closer fit to the shaft and make some replacement locating teeth. Not a big job at all, but it doesn't "feel" right. Rodneys have known rigidity issues, so to have a loose fit on main drive, at the end of a cantilever, seems asking for problems.

Has anyone else had any experience with this sort of issue?

Drive system - the plate is screwed on top of a pulley, so the milling quill can move up and down, and be driven. PS it is upside down...

Underside of plate, with the locating teeth. Oddly no adjusting movement, the screws only hold it in one location.

Any with any Rodney experience, please comment. I'm still learning traditional British Engineering, but the Rodney seems to have several odd design ideas. Any hints on how to attach it to the bed, without three hands, and a fear of bed damage? Anyway of ensuring it is located correctly? Due to its size and shape, set square access is not easy.

Or does anyone know of where I can get a Rodney parts list / manual?

Many thanks,

Nicholas

Hello again,

Just an update. Super gluing top slides does not work....lasted about 30secs, and then went again.

I have ordered a Improved Top slide from Hemingways. After telephoning them, it seemed to be a all-round better solution. It compromises the flexibility, but gains rigidity, and hopefully better finishes.

In the interim, I decided to do a vibration survey of my lathe. Just using an App. It's quite interesting too see that minor changes make huge differences. So the time hasn't been entirely wasted.

Anyway, many thanks for all your help, and advice.

It was most reassuring to see Colin had the same problem. It stopped me kicking myself so much.

Yours,

Nicholas

Thank-you all!

I am rarely on here, but whenever I have problems that have left me searching, this site always seems to have incredibly helpful people to give one light at the end of the tunnel. I now have three routes to try - a source of the part, a suggestion for substitutes, and suggestions for repairs.

As for the cause of the cracking, I am still slightly lost. I had a nasty incident while parting off a week ago - 1 second my parting tool was cutting easily, and then with no noticeable force, the end 1" suddenly broke off. I was cutting EN16 of 1/2" at 250 rpm, So no excessive forces. I immediately completed the cut with my Eclipse blade, with no problems. I have since done several hours of work, again with no issues. I then adjust the Top Slide, and just the force of hand tightening, caused it to crack.

Being a secondhand lathe, I don't know it's past life, but would have thought a 40+ years old lathe, would have shown any major faults prior to now.

It maybe that my tool height was not correct. I had great problems with good finishes initially, and found the 3/8 shank tools was about a 1/32 too high, at the lowest setting in the Dickenson quick change tools post, so had to grind them slightly. This I found slightly odd, as the tools and post are designed for the Myford..

So it might be, that I had the tool at the wrong height, and it dug in, causing the tool breakage, and the initiating of the crack...

I have a Rear Tool Post, and the Myford Cut Off Slide, so may experiment with those. I really am not good at parting off, so after this, will probably use them as a safety first solution.

I am tempted by the Improved Top Slide, as I have a Taper Turning attachment, and the tail stock is a pain - one has to faff with angles, and loss of rigidity due to the over extension of the tail stock.

Anyway, I am more thinking allowed now, than coming up with solutions.

Many thanks, again, I shall ponder the ideas, and decide later today. So hopefully my lathe will only be down for a short while. I need to make two axles for my 1927 Omega Motorcycle. It is grey out today, but the weather is supposed to be good for the weekend!

Yours,

Nicholas

Hello,

last night I adjusted the Top Slide Base on my Super 7, and noticed the screw give totally. Much to my surprise, I discovered the cone had cracked into two pieces.

As a very temporary fix, I have glued it back together with super glue, but as it was impossible to match the granules it now creates a very tight fit.

Today, I tried all the usual Myford spares people, and no luck. I am happy to wait for one to come up on ebay, but that could be a while. So I was wondering if there are any suitable alternatives?

Hemingway seem to produce a couple of options - The Gibraltar, or the Improved Top Slide.

So, I was wondering if a) Anyone has any suggestions of where to find a replacement. b) has anyone else machined with a super glued Top Slide Base, is it really really stupid? c) Can I use this as an opportunity to buy an alternative?

I have attached a couple of pictures of the slide base, to show the type, and the repaired crack.

Any help, ideas, or just mocking, will be gratefully received.....I feel somewhat lost without my lathe.

Many thanks,

Nicholas