Member postings for Neil Lickfold

2024 is also very good for conrods. It is important to have the grain of the material in the direction of the rod. Can't really fail with round bar, but sheet stock, some suppliers just cut material from the sheet in the most convenient for them situation. A cross grain rod will fail, especially if it is 7075

Neil

Very sharp tools, small cuts.

Not sure if they were made by some one or a purchased item, but we used to have a segmented piece held by 2 wire clips. The segments allowed you to hold a square bar in a collet and went up to 3/4" square. The smallest was like 3/16 or so. They were all imperial. it was just 4 cord segments retained with a wire clip at each end and used in the collet chuck.

Neil

We make bushes from it all the time from 20mm ID to 100mm ID. I use coolant and sharp tools, ie the same geometry as Aluminium, but use the surface speed and feed of Stainless steel. The grade we use will work harden like BeCu does , if it rubs and gets too hot. Drilling is the process that will make it work harden the most, centre point sharp drills with the square edge like for brass works very well.

Neil

Andrew, I was going to modify my Myford with dog clutch. But I put a 220V 3 phase motor on the lathe when the single phase motor died. As it has a tuning to breaking and acceleration when changing direction, I found that there is no need for the clutch. I can set the carriage position with a micro switch that stops the motor going forward and comes to it's rest quite quickly. Then, after retracting the tool, I turn the forward position switch to reverse. It goes into reverse until I turn it to the stop position. It stops within about 0.02mm or so on the micro switch.

Neil

A pair of spanners can allow a zero torque on the spindle and machine tool. Although they have the huge toque value for the ER40, I have only used about 30ftlbs and it is fine for every thing I have been doing. The smaller ER 20 I use less than that. Never had a cutter come out from ER40 or the other smaller ones. I also don't go trying to take the max possible cuts etc either , when holding a cutter or a work piece.

Neil

Too late to edit, but for any collet that I want to be running good, I have been buying the high precision collets from Regofix. In saying that, I just tested a cheap set of collets that is going to be used to hold parts for milling hexe's etc, so does not need to be all that concentric, just has to hold the part. To my surprise , the 4mm,6mm, and 8mm were better than 0.01mm at the collet face and at 30mm out from the collet face. This is a cheapo ER20 set. For my cnc wood router I use only regifix and it is ER20 also . I tried the Regofix nuts and the regular nuts on the 6mm collet. Of all the nuts we have, the regofix and 3 of the no brand were very good. 3 of the no brand made the collet not run true at the 30mm mark and next to the collet face was showing nearly 0.02 run out and .06mm run out at the 30mm . This is the worst of the no brand ER20 nuts.I have now identified those nuts and will use them on the milling fixture for Non important things. While at it, I checked with an indicator on a known bad collet for concentricity. As I suspected, it did not run concentric at the front to the back of the collet. It has a reading difference in the front to the back of about 0.03mm. I used a red marker for the front high side and a blue for the rear high side. They are almost opposite, which makes sense and explains why the test piece with that known bad collet is no good. What I will do is set up and regrind the id concentric and see if I can save it. It will become then a special sized collet effectively. I will put that onto the oneday list.

Hope this info may help some people out there. I have read about the high torque required to hold stuff with the ER40 collets, and for what I do with them, have not found a need to tighten any more than what I can on the spanner lengths that are supplied by Regofix or the other spanner suppliers for the various ER sized systems. Granted ,most of the stock I hold is turned finished bar in most cases, or is Carbide cutters.

Neil

With ER40, and any ER for that matter, the thread for the nut must be concentric to the taper bore. I would check that the very inside of the 8 deg taper is concentric to the front of the 8 deg taper. If they are both correct, ie better than 0.01mm in both cases, then check the thread. Set your lathe for screw cuting, set to 1.5 pitch, turn by hand and when the carriage is engaged and feeding at the the same rate as the thread of the collet chuck. Put the dti into the thrade and see if it is concentric to 0.01mm. If both of these tests show to be within 0.01mm, then check with some bearing blue on the 8deg taper and a collet. just lightly hand fitt to check that the tapers are coincident. If all these are good, then most likely it will be in the collets themselves. A simple check is to place the collet in by hand,without the nut, and with a finger indicator, carefully check for the run out of the collet itself. The front of the collet should be less than 0.01mm DTI reading. Then put the collet nut on and test again. This will check if the nut in influencing the concentricity of the collet.

Neil

When using Rotary tables, the more rigid and shorter the moment the better. So getting a regular 4jaw and mounting it directly onto the rotary table will make a very big difference. You can also mount a 3 jaw onto the rotary table, but will be limited to the repeatability of that chuck for the next work piece. Generally 4 jaw chucks have a greater holding ability when it comes to milling. A smaller chuck for small items and a larger chuck for larger items. Quite often it is easier to hold the rotary table by clamping or drilling and tapping into the bottom face it it is not already done so,(Take care if it does not come tapped on the underside of the base) and then use the T nuts and some bolts or cap screws to secure it to the machine table. Sub plates used to be very common many years ago, but seem to be a forgotten item these days. They can also be used to expand the clamp area of the machine tool as well. Neil

I had a Dremel 3000, it was junk. It's main problem to me was the shaft for the collets was a long way out of running true. They replaced it 3 times, so got them to replace with Dremel 4000 and paid the difference for the upgrade.

Never did get to properly try it, as any too I put into it , wobbled so much, it was not good enough to use. I checked the taper on the inside of the spindle, it was out of concentricity by 0.5mm nearly at the end of the range of my finger clock. That was the 3rd tool I looked at and wish that I had looked at the others with a dti on the spindle inner shape. Yeah I could have set up and recut the collet seat shape, but when buying new you expect it to be OK. My old dremel from 1987 has less than 0.03mm total and that includes the slop of the old bearing.

Neil

Trichlorethylene mixed 50% with castor was sold as Glow cut right up till the early 1980's.

I am not sure what allows castor oil to make tight parts assemble. Model diesel engines work because of castor oil, allows an over size piston to go to TDC without too much friction and without wearing or causing gauling of the materials. It also allows the contra piston to be fitted and then can be adjusted up and down, also without gauling or seizing.

Neil

Castor oil can allow you to ream a hole slightly smaller than the reamer itself. Castor is one of a few products that allow parts that would be a press fit to be a slide fit, to about 0.005mm to 0.008mm in interference fit in a 12mm to 20mm hole.

Neil

You want to buy the HSS toos made with cobolt and vanadium tool steel. The higher the cobolt the longer the tool life. I have seen it as high as 9%, but mostly these days it is in the 5% range.

Neil

The most important part about slip gauges is keeping any form of abrasive off them. To clean them, use only materials that can be used to clean glass lenses without scratching. A lot of paper towels are actually very abrasive and will do damage to the slip gauge surfaces. In home workshops, slip gauge sets can be just so handy to have at times for so many things.

Neil

The gauge plate that we buy is flat to less than 0.03mm in general. So when a part is made, it is heat treated It can be ground and be at the nominal size in most cases. Sometimes it goes .02mm or .03mm undersize, but in our case the thickness of this part is not critical. We make these blades from 1/8 stock, 6mm 8mm and 10mm from 2inch wide to 100mm wide. It is O1 oil quenched tool steel.

Neil

Shim stock starts at 0.005mm, 5 um thick, then 0.01mm, 0.02mm, 0.0254(0.001 inch) , these will allow very fine adjustments. It's not very cheap, but is available.

This place claim to make shims from .01mm and up. They mention 0.005mm . The shim we use comes from Germany , is 0.005mm thick and is 11mm wide.

http://www.hollinbrow.co.uk/hollinbrow/final.asp?id=63 Their shimstock. 0.010mm
0.0127mm ,0.0150mm,0.020mm,0.025mm,0.030mm,0.035mm,0.040mm,0.045mm,0.050mm

What Diameter is your work piece in the video? What RPM did you have it running at ? I turn on the myford at about 16 to 20 m/min as a surface speed, so if it was a 1 inch bar, would be about 200 rpm with coolant. Without coolant I use 10 to 12 m/min . With a .2mm radius tool, I use about 4thou per rev feedrate. Ti is a very poor conductor of heat. So dull tools heat the work piece and the heat becomes more local . In turn it work hardens the immediate cutting zone.

Neil

Toolmakers buttons are useful in situations where it is not easy to find the datum on the machine tool and need the hole or detail to be accurately placed. There are many ways of using them. It does not have to be for boring a hole. They can be used also as a reference position when milling pockets or other details. any hole from m3 and up can be used. I have used an M2 on one job before. The buttons are easy to use and make. The most important part of them is knowing it's size. making a series of a nominal size and all the same is very convenient when using gauge blocks or set standard lengths etc. Now days the tool makers buttons are being replaced by reference holes that are precision placed etc. These are then latter referenced like a toolmakers button is.

Neil

From my experience in Ti turning and drilling, there are plenty of warning signs that things are not going well. Way ahead of any fire type situation happening. 1st warning sign is that the workpiece is getting hot, with water based coolants for Ti, you will see that there is steam coming off the work piece. That tells you right away that the tool is dull or you have the wrong feeds and speeds, or the wrong geometry for Ti. There are loads of drills and various turning inserts specifically for turning Ti and they cost about the same as regular general turning inserts, if you buy from a supplier that has clients using them. The highest risk times is drilling and parting off. It seems that most problems in drilling is a dull drill, and too high a surface speed and too slow a feed rate. Parting off issues occur when the tool starts to get dull at the end of cutting off a part, and not realising that it was dull to be cutting the next part. Having a chart /record of how many parts you make before tools dull off is the most valuable info that the books don't have. I use grade 5 and 23, 23 is 5 with low oxygen. Ti-6AL-4V Ti64 as we call it. Neil

I suggest to cut dry with an air blow, or flood coolant. You need to remove the micro swarf away, so that it does not get to try and jam between the tool and work surface. That is the most likely cause for the bad surface finish. A lot of industrial machines, cut from the back and the tooling is effectively upside down, Gravity aides is getting the chips away from the cutting edge. Normal home hobby lathe set up, gravity has the chips staying on the cutting tool surface.

Neil