Member postings for Neil Lickfold

Nitro Methane is the most effective solvent for super glues. It usually does not effect the car paint either. Acetone can attack some car paints. Some superglue de bonders contain Nitromethane.

Neil

Tungsten carbide tools will cut to Rc 65 . Run the surface speed at 25 to 35 m/min So basically in your case you should be able to turn it at about 400 to 500 rpm, take cuts from 0.1 to 0.3 mm deep, about Ø0.2 to Ø0.6 mm cuts, and a feedrate of 0.05 to 0.08 mm per rev, basically 2 to 3 thou per rev. If you use ceramic inserts you need a lot more rpm's and flood coolant. The gold coated carbide works well so does the newer vapour coated insert like the VP15TF coated inserts from Mitsubishi. That will give you a coating comparison to work with.

Neil

Some really good info in the above posts. What can cause scratching and effect your finish is the polishing cloth you are using. Home paper towels are terrible at scratching. Lens wipes are very good and so is Hydraulic lint free wipes. Cotton cheese cloth that car polishers use is very good as well. Very soft balsa wood makes for a great lap and very fine polishing compound holder as well. A little bit of very fine diamond in balsa wood lasts a long time and works well. The hardest part of it all is to keep the contaminants away from one process to the other. You just can not ever be too clean when it comes to polishing. Cleaning is essential between grades . The finer the finish the more it is involved, especially at keeping the contour to form is definitely easier said than done. There are lots of little tricks to keep the form correct and each situation will use a combination of ways to achieve this. Like polishing in 2 directions to ensure you have the scratches from the previous grit fully removed before going to the next level, etc.

Neil

Thanks for the video and the posting on the holder you made. The Dickson one that I got with my Myford is very repeatable. One of the best things I did is to clean up any burs etc around the cams, and to make both cams the very same height. That way any tool can be used on either post side and get the same result.

Neil

https://www.kyocera-unimerco.co.uk/Kyocera/metal/turning-tools/turning-inserts/cc/UpdateFacets/

This is the UK site, The inserts I use are these, Kyocera CCGT060202MP-CK PR1425

Product code TKD01307 PR1425

A better picture is here,

https://www.kyocera-unimerco.co.uk/kyocera/metal/turning-tools/turning-inserts/cc/tkd01307/

Strictly speaking, these are a stainless steel grade insert. I used these inserts for cutting the modified outer bearing races to make my home made Magneto style bearing.They are not real cheap, but unbelievably good. You get a very good surface finish with hard steels, P20 type steels, and mild steels, as well as Aluminium alloys and brass, bronze and copper. I don't run my lathe any faster than the top pulley on the low selection, about 700 rpm or so. Run at a feed rate at between the lowest on the feed box to 6 thou per rev, or just by feel. Mostly I turn by feel and look at the chips coming off. For depths of cut, it will easily cut 0.5 to 1.0 mm 1mm to 2mm on diameter. I have not tried taking a 3mm diameter cut, but the packet says up to 3mm on diameter.

You most likely have the wrong inserts for cutting brass. A lot of carbide inserts are not sharp like a ground hss, but are often very blunt/ dull. This is intentional as the tool relies on high surface speed to plasticise the material and induce chipping and very high metal removal rates. For home machines, like on my myford, I use the positive geometry and often coated inserts. These are sharp like a hss tool. They will give a very good finish on a variety of materials and don't need a lot of power to be cutting effectively. I like the Korloy from Korea and also the Kyocera from Japan. They make very high quality inserts and between them, make a selection for everything. The Kyocera ceramic inserts are fantastic for turning hard materials.

Neil

I have used the J/B Weld original for many years, since 2003, and have never had a failure of the mix to set. I measure out equal volume of each. Then mix usually with a tooth pick or bamboo stick. Mix very thoroughly then apply. I have not used it in cold conditions. In winter I bring it inside the house, summer in the shed is fine. For a faster cure, I place the items in a small bench top oven and set it to the defrost setting of 40C to 50C and leave it for 6 hrs and it is set. I find with most glues and epoxies, if they are at 18C or higher they mix and set better than if they have been colder at say 12C or colder. Don't mix epoxies with anything Teflon or on a teflon board. The smaller the batch the more accurate you have to be. I draw around 2 small coins, and that has become my minimum mix size.

Neil

Who sells the Dickson or a holder that fits the Myford Dickson QCTP in the vee holders and standard too holders.?An engineering outfit out here in NZ sells a copy , they are called Machinery house. Their copy from 2009 interchanges with the Dickson. Their latest stock does not however. Lucky they took back the holders and gave a full refund.

Still could not go to the Ebay website and get any holders.

Neil

The lathe won't be your issue. It will be making or buy the tooling to make what you want, like a roller box tool to make your pins and things like that.

Neil

Sometimes secrets are really necessary in engineering workshops. It can be quite a simple idea that keeps a company in business. But in most cases if you really think about it, it becomes obvious. But not all are though. I don't mind passing on the knowledge of skills to do tasks, ie hard turning parts, or fitting tapers on injection moulding tools. If you do know the secrets, often it pays to keep them, especially when it maintains a friendship with the company or customer. Sales reps have to keep secrets or they will not be allowed on site to sell their products.

Neil

I went to that link and just did again now, it shows no products for sale. Is it because I am viewing it from NZ ?

Thanks, Neil

Can you post or PM a link to where you brought the tool holders from please. Thanks, Neil Lickfold

When not using a dedicated lapping block, I glue wet and dry paper to something flat, like a piece of plate glass. I have found that the spray can of photo adhesive is good enough for this job. It has enough tack to keep the paper down flat , but can also be removed when the paper is dull.

Neil

Edited By Neil Lickfold on 12/06/2016 20:29:30

If you have enough coolant flow or compressed air with oil mist, most of your issues will vanish. I have found that if the material is a little gummy , it can stick to a cutter somewhere and leave these types of marks on the work piece.It can also happen to fly cutting as well if the cutter gets a build up on the cutting edge. Again usually with what I call gummy type of materials. Having a polished surface on the top cutting surface helps with a home made fly cutter.

Neil

OK Ian, any more info or photo's of this machine ?

Very interesting indeed.

Neil

Since I made a 0.5mm pitch cross slide screw and nut with the 0 to 100 dial from the 100 thou pitched screw, I can easily turn diameters to 0.005mm in diameter for small parts under 30mm diameter. The advantage is that the amount on the mic is the same as the cross slide dial. On lengths I can easily get to less than 0.01mm for lengths. To get lengths less than 0.005mm does take a lot more effort that is for sure and then knowing the work piece temperature can be important. For the head inserts for engines making the lengths is easy to 0.01mm and the diameters to within 0.005 is easy for me. Pistons are the hardest part that require making something to Ø 0.001mm is very difficult but can be done. But the pistons are made to fit a specific liner and not just made to a specific size to a tolerance of 0.001mm which is a very different thing. Precision milling to better than 0.01mm does take quite a concerted effort that is for sure and most lower end mills I have seen for the home workshop are not capable of better than 0.02mm precision work.

Neil

This is probably the worlds most accurate hand held micrometer,

http://ecatalog.mitutoyo.com/MDH-Micrometer-High-Accuracy-Sub-Micron-Digimatic-Micrometer-C1816.aspx

This is the new series of measuring technologies that will make the mechanical stuff obsolete like digital calipers have taken over from vernier calipers, but maybe more so. Interferometry I think is the next level of accurate measuring. Not priced for the hobby market or the small engineering companies yet, but prices will come down I am sure.

http://www.keyence.com/products/measure/micrometer/

Neil

When making things accurate, several factors come to mind. Does it actually need it ?. Is the material actually stable enough to achieve those sizes? Can you measure it ? Did you compensate for the temperature of the part at the time it was being made. This really applies to Ali parts that are bigger than 100 mm diameter. I can remember ceramic gauge blocks coming onto the market. The down side was the expansion difference at different temperatures. So if the tools were not 20 C, it would show an incorrect reading, especially when checking the larger mics, or when someone was checking a milled pocket on a plate in the summer time. So the steel gauge blocks are still used and they sold the ceramic ones. I see that Mitutoyo now sell a sub micron micrometer these days for the very series people. But they will be superceded with laser based measuring equipment before too long or non contact measuring. Simple shapes are a lot easier to make to 0.01mm than a complex shape. If the shape is complex, a lot of cnc lathes are not capable of making a part to 0.01mm accuracy. Usually as they do not have the measuring gear to measure the part, or they do not have the measuring equipment to measure accurately the radius of the cutting tools to properly set the geometry offsets for the programming.

Neil

Clive, the best and longest lasting machines I have worked on, never used soluble oil on the machines.They used straight cutting oils, that were thin like a honing oil. The machines that used soluble oils had wear in them as to the almost new condition of the cutting oil machines. I'm a convert of using oils and not water based coolants now .

Neil

They do not like any oil accidently getting on the armature or brushes.

Neil