Member postings for Neil Lickfold

Having used both R8 and MT3, if the spindle is good and the register for the R8 is the correct size, then R8 can be often purchased quite cheap for after market parts like boring heads etc.

The MT3 like been said, a lot of people do over tighten them.

An advantage of an R8 over a MT3 , is if the collet or piece is undersize, the back of the R8 keeps it well aligned while the front taper clamps down on the tool and it still runs quite well. That is not the case with the MT3. If you only ever have nominal cutters etc, then the MT3 is fine.

See what else you want in the way of other holders and drill chucks and arbors etc and price them up and availability.

Often availability of accessories that you will use can be a real deciding factor, and not just price alone.

Neil

This is quite interesting. My Mill is MT4, I have collet sets from ER11 through to ER40. But unless I get the really good ones, it is just not the same as a MT collet or any other direct spindle collet. The only advantage of the ER system, is that when I change to a drill chuck, the head height stays at about the same height for most things that need both drilling and milling. I think that the MT collets will hold better than a ER , simply because there is one less something to not be concentric. Most small cutter come on 4mm shanks, there area few 3mm shank cutters, then there is a few 5mm, but standard is 6mm, 8mm 10mm 12mm, If your mill is 2 MT , 3 to 8mm will most likely cover the range for you.

I'm looking at a set of 4,6,8,10 collets will cover most of what I need.

Neil

A lot of the plunger type indicators , use M2.5 and M3 that I have seen so far. The M2.5 is 0.4mm pitch . The M3 is the standard 0.5mm pitch. I have made several for the plunger indicators. I made my extensions from 3mm and 4mm ejector pins. They are nitrided on the outside, are reasonably straight, cheap, and once through the nitrided coated the steel is not that difficult to turn or to thread cut. I start the thread by thread cutting, then use the die as a chaser to follow and make it to the final size. When I need a flat surface, I use the head end of the ejector pin. But most of extensions have either had a 2.5mm ball retained with loctite, or have been points, or a blade of some sort to get to measure or compare a feature.

I have found the threads on the plunger matches a M2.5 capscrew or M3 capscrew really well, while the tip thread is often loose and undersized by at least 0.1mm in diameter or more sometimes.

Neil

For hardening a part like your cutter, I would be heating the solid shank, and allow the heat to transfer to the thinner part. It would need a hold time of about 5 minutes. With a gas torch that seems an eternity . Don,t over heat and get it all scaley, and I always use a carburising flame for heat treatment.

Practice is a good idea. Real daylight or no light is best to get the idea of the heat when getting the steel hot. There are colour charts on the net, but getting them nicely printed I have found is best from a photo centre.

Neil

There is W1 and O1 in the silver steel range. The W1 is water quench. With the W1 , I was always taught that the water should be heated to at least 40C if using water quenching, then leave in ice water after the initial quench.

Polish, keep oil free, then temper 1st time at 150c and then slowly increase temper temp to the desired hardness. After the 1st temper at 150C for minimum of 1 hour per 1/2 inch of section, quench in boiling water, then retemper to the desired range. IE a ball race needs to be retempered at 150c , but cutters in the 180 to 210 c range.

The way the quenching is done is also important, it does require agitated oil or water to be effective.

Sometimes shell cutters fail due to no internal clearance , or outside clearance.

Neil

Here is a link to the Korloy through a UK agent.

https://www.cutwel.co.uk/lathe-tools/multifunctional-turn-drill-face-and-boring-systems/quad-turn-multifunctional-3xd-tool-holder-qtrl-3-series-korloy

They are really ment for cnc with through coolant. But can be used on a manual lathe with a squirt bottle. The smaller 10mm and 14mm work well on a Colchester sized lathe. Not tried them on my myford. I have made my own Dbit tools for non ferrous materials on the Myford as a combination drill turn tool.

With my 1/4 inch carbide , on ali and brass , dont go more than 30mm deep. In plastic and wood I go upto 70mm deep.

Neil

I no longer have a tangential tool and seldom use anything in hss. I don't run my lathe faster than 800 rpm on anything, and the modern carbide tools are just awesome , especially for the amount that can be done on 1 edge.

There is a huge range, and more places are now selling lower numbers of inserts. Only this week, a trade supplier who only last week, the min quantity was a box of 10 or how ever many was in a packet, now offer single inserts or a mix and match option, and they did not make the single inserts more expensive either. So a selection of different radius options is very viable now.

If I was to buy a new tool, it would be a multi turn tool. They groove, turn, and have different geometry inserts from full radius to various bull nose inserts. The 3mm wide tool seems to have the widest range of geometries. Another interesting tool is the MDT tool, where it can drill, bore and outer turn with the same tool.

So there is some really interesting stuff out there for sure.

Neil

Actually if you use castor oil, you can have a 0.001 inch diameter press fit and assemble it without too much trouble at all. No need to heat anything.

Neil

Grind it. With a dremel and sanding drums works really well. The use a vacuum cleaner to keep the dust to a minimum.

When I made my Myford 0.5mm pitch cross scre wand nut, I just used the normal RH tap , and screwcut the thread with a traveling steady rest.

It does need to turn the opposite , I it is no biggie. You just have to remember which way is feed out.

I find it interesting the new software with high speed machining . Even though at times the cutter seems to be cutting too much air, in some cases it actually becomes faster and better for the machine tool life. One example is we had a part and the corners has a 0.5mm radius. The software used to slow down and then speed up trying to get around the small radius. The new software as it came off the end of the part did just over 1/2 of the radius and did a circular path then entering and finishing the other 1/2 of the radius and then goes down the next side. The machine did not bump around as much, the part looked nicer, and the time to make it was actually less. Not what I was expecting at all. Have fun Jason

Neil

The copper works well as does the split nut method. On very small stuff like the M2 thread I have found that a thread mic with the anvils, not the points to be the best. The biggest problem I find with small threads is the variation in the taps themselves and the thread that is in the nut. As for fine wire, music shops sell the wire in 1 thou diameter increments. I buy sets of wires in a selection. Its what I make my circlips from for the model engines .When I used to make up wire for thread measuring , I left it very long, and looped it around and had tow on top and two on the bottom. As it was hinged it sort of stayed together. Another guy I worked with made his like a coil spring. It was just 2 loops. These he put tooth picks for handles on and would unwind the spring to fit over the thread form. This was for M3 and M4 LH threads for inserts. Both worked well, but the thread mic is quite fast. Down side to a thread mic is the purchase cost of the anvil sets. What I do like about the thread mic, is that you can make different anvils to suite differing applications , IE ball anvils etc.

Trying to get concentric threads I had always found difficult. So one way was to modify some taps, and on the lead in area, make it very close to the drilled size hole. This make it into a piloted tap, and that has solved a lot of issues for me. I use it to get the start of the thread form concentric, and then follow through with the regular tap. 

Neil L

Edited By Neil Lickfold on 25/02/2019 18:32:51

It is a easy way to have an auto collet closer using the 3 jaw chuck.

Neil

Hey John, I like it. That is quite a trick setup , especially the fact that the chuck has a limit on the opening.

As for accuracy I am sure it is better than 0.01mm if the collet is a precision collet. For it's application with full contact engagement in the collet looks really good to me.

It would also lend itself to the use of distortion collets as well. Very interesting.

I might have to make up a set of jaws to allow this to happen.

Neil

I got some holders from RDG last year. Very happy with then and they fit the Original QCTP bodies that I have. I have 2 genuine and one clone. The RDG holders fit all 3 tool post blocks. Not super cheap, but I consider buying them was better than me setting to and making them. These RDG holders are way better than the clones, and are very repeatable. Lucky I only have 3 clone holders in total, so are set on tools that I use occasionally.

I just went to the RDG site, but the holders I got last year I do not see them now.

Neil

Apple cider vinegar will help with the corrosion on the parts from the degregrading foam.

I have not found a foam that does not break down over time. The best I have found is wool felt for a liner.

Neil

A drilled hole with a piece of weed wacker nylon, works very well as a mechanism for keeping a screw or a nut from loosening off. An alternate to the nylock nut. A Ø2.6mm hole is plenty of clearance for the 2.5mm line X 3 to 4 mm deep. Make the nylon about 1/2 of the thread height. It will squash up and make the screw tight to turn.

When I was making a series of parts with a thread and a 45 deg taper that was a fit to another part, I made a series of tool stops. So I faced the end of the bar, then tuned the Ø6mm length based on the tool stop that touched the end of the part. Then when the diameter stepped up to 9mm , the length was on the step of the tool stop,and again touched the end of the work piece. The final diameter of 13mm and and allowance for parting off, was the last step in the stop bar. So it is progressed a bit like a wood workers tool. The taper turn tool had some of the material removed already, and again had its own tool stop that referenced off the end face of the part.

It worked really well, and is only as good as the stop is set / made. The down side is if the radial distance is too close, it becomes not a very practical of an option.

The Parting tool used a stop as well. When the part was at about 3mm to go, the stop had worked its way off the diameter of the end detail, so it was free to fall and not jam up on the parting tool. My lathe does not have DRO. From batch to batch, these parts were quite accurate. As long as there was no swarf on the end face etc, and no pip at the centre. I normally where ever possible, leave a centre drill spot on the end faces. That way the tools never have to turn to zero when facing, Makes all your tools so much longer , on harder materials for sure.

It looks to me , that part can all be made using a MDT , multi direction Turning tool. Looks like a parting off blade, but has side clearance to be able to takes cuts left and right. If both ends are the same diameter, you can plunge cut the outer end, then go in to the 1st shoulder length and cut to finish diameter and traverse out. Skim the od, then plunge cut the back shoulder, and the remainder of the back material, then part off.

Without knowing the stock you have and material etc. But with the above approach is quite easy on a Myford, If you have decent digit read out, it will be even easier.

Keep in mind, that with most digital readouts, you need to be still going in the same direction every time to get really good results. A bit like taking away the backlash on a lathe nut.

Neil

So, if you now have it correctly registered on the spindle nose. Also you have re turned the inner 8 deg taper per side. If this is correct, then the next area of error is the thread for the nut. If the thread for the nut is not concurrent to the 8 deg taper, it will not work correctly either. The thread will be a 1.5mm pitch thread. So can be recut again with care.

Then you have the collets and collet nut itself to sort through.

As simple as the ER system is , for it to work properly, it all needs to be concentric and true.

Neil