Here is a list of all the postings Neil Lickfold has made in our forums. Click on a thread name to jump to the thread.
|Thread: Making a ring mandrel- jewellery tooling|
If you have a lathe, just make a couple of form tools and turn up the ring to the profile and diameter that you want. I made my wife a Titanium wedding band for our 15th anniversary . I made a form tool for the inner shape and a form tool for the outer shape, parted it off. Then set it onto a mandrel and blended the side that was parted off. To get the size I just asked her to take a ring to the jeweller in town and got the sizing off them. They told her how many mm diameter it was.
|Thread: Pros and Cons of the ER collet system|
Raymond, I put a piece inside the collet that is about 0.01mm smaller than the bored collet. I just cut them slowly with a slitting saw on the cuter grinder, so not milled. Then debur them. I also make adapters from the ER40 to ER11 for holding 1mm drills etc. I also use them in the collet chuck when holding small parts, less than 6mm diameter. I wish that I had live tooling but it just has a 12 station VDI 50 turret, 6 outer and 6 inner.
|Thread: ER Colletts - will they hold my plug?|
This is where I posted about the ER40 collect chuck that I made for holding parts at work.
|Thread: Pros and Cons of the ER collet system|
The collet blank is just from P20 tool steel. I put in 4 slits from the front to about 4mm from the back. Most times the parts are better than 0.02mm diameter and the 4 way slit is good enough. If more range is needed, I add 4 slits from the back and finish at the retract groove. The blackened collet chuck body, sits into 50mm bored softjaws that are torqued to 90NM on the M12 capscrews to keep it all the same. The hydraulic chuck pressure is set to #10 of 24. It was bored and threaded in the softjaws when it was made. It has dedicated softjaws and is always set in the same radial position. A really important and often over looked aspect of the chuck body is the concentricity of the outer thread for the nut and the 8 deg bored taper. If these are out, it will not work as well as when it is actually concentric. I make the thread to be quite a neat fit to the nut that is going to be used and only use the one bearing nut in this case, as it is used to hold parts and not cutters.
The plate sitting on the nut is the standard stop and can be used with the tube as an extension needing greater than 25mm diameter but less than 30mm. The cap-tube is the standard extension that takes 25mm diameter stop blanks and can be used with the other tube as an extra 75mm extension to the cap-tube.
I have made for carbide cutters with my CNC router which uses the ER16 collets, I made some shrink holders. They work really well. But I have access to the use of an induction heating unit which makes it easier to heat and get the cutters into the holder. Also I needed to modify the diameter of the collet at the front of the groove, otherwise you can't the nut onto the collet. There is a limit as to how long of an extension nose you can make and it's diameter in order to get it all together. I also made some other tools, like a 4 mm ball end with the ER16 shank to use as a setting piece to touch off with and finding the work piece position.
This is what I made for holding various parts at work. I make support pieces to support the collet at the back end, either as a button or as a combined end stop and collet support. For some jobs I make a collet specific to that part with a step in it or what it needs. The outer shape of the ER40 blanks is a standard program in the lathe, so just need to edit the ID detail. These normally work over a small part size range, less than 0.1mm variation. I have also made some Delrin solid colets, and use them as distortion collets. The part neatly slides into the plastic with an end stop on the collet chuck body. So makes it into a dead length set up. Then the plastic distorts and holds the part nicely. With a steel step collet and stop I can hold and second op some quite thin parts down to about 1mm thick. Neil
If you use the BIG brand ER colets, they are far better than the Regofix and all others. I don't have them myself as they are too expensive for me. These hold cutters a lot better than any other ER collet and their collets only have a 1/2 mm range in size with a recommendation of using them on the nominal sizes. For holding milling cutters, you can't beat a shrink fit system with good quality shrink holders and an induction heater system for installation and removal. Mainly carbide cutters are held in the shrink system. The earlier video was a bit misleading by not showing the 1st test at real speed and sound. The second cutter should have been in a new path instead of going in an existing slot. For home use the appropriate ER collet system size is important to get the most out of the holders for cutters. Using a bigger longer collet is only good if the cutting tool is still held by the full length of the collet. I don't see any point using an ER32 as an example when the length of the 4mm end mill does not allow the too shank to be fully supported. Then you are better off to have a shorter collet chuck like an ER16 collet chuck for example or the even smaller ER11 collet chuck.
|Thread: ER Colletts - will they hold my plug?|
With ER collets. I have made a collet fixture, I use at work. it goes into a dedicated set of softjaws. It has on the back a plate that is used as a stop. This is for ER40 collets. I have a set of spacers and also spacers that have the diameter of the work piece that locates into the last 5mm or so of the ER40 collet, with the front of the stop being used as a true face for the part to sit against. The area between the part and the 5mm engaged with the collet diameter is relieved a little, I make it smaller by 0.2mm in diameter. This allows me to hold onto parts sometimes only 2mm length to hold. Of course you only take cuts according to the ability to hold the part.
This effectively makes the ER collet like a fixed length collet chuck, which is great for repetition of parts. I also make my own ER collets for specific tasks and only takes parts to a tight limit, Exact size or smaller by 0.02mm max. The collets I make , I only slit them from the front and leave the back as a single ring. The slits only go to about 5mm from the back of the collet. I drill a hole for the end point of the slots. If the parts need to all be the same length, then I make a stop block to suit. The stop blocks are held by a M8 capscrew. But a smaller similar system could be made fro ER30 or any other ER collet size.
I can take some pics if anyone is interested and then add them tomorrow.
|Thread: Analouge tachometer|
There are optical tacho's available that go off the light from the prop and will go to 50k or so rpm.
Mine is a futaba and is about 34 yrs old. I think place like hobby king sell them and maybe model shops inthe UK might also sell them.
|Thread: Is CNC cheating|
This is an interesting thread with loads of varying opinions. It seems to me that a lot do not realise how much skill is required to make something cnc and to make it accurate and have the really nice finish. There is the design or cad skills as well as the cam or cutter path skills. Of course to a great extend the shape as ling as the tool can access it, it will create the geometry. Accurate things need cutter compensation and radius compensation, if not on the machines controller on the cam package making the part. If you can measure the geometry of the tools being used, and create a cutter library with the tools of the correct geometry, then the cam side will create the compensating code. Depending on the equipment being used but the path may need to be modified to compensate for the idiosyncrasies of the machine tool itself. I make stuff on my myford with no digital read out is one end of the scale and make parts on a cnc lathe or a cnc wood router. There are some precision parts that just can not be made by hand and do require the control of cnc equipment to generate the geometry to the level of precision that is required.
The final answer has to be how to you weight the varying skills to make the same item ?
What weight do you give to the person who can 3d draw a propeller with the correct sections and geometry and then program a machine tool and create the tooling and method to make it over someone who hand carves an approximation of the same propeller . The hand carved prop will be not be as equal in performance and will not have the same precision in it's manufacture. The person who used the computer and cnc has a far greater skill set than the person who just carved one up. In this example I know as I have done the hand carved props and they are way easier than the skill set to learn to draw it all up and then create the cutter path. I just don't have the cad skills to draw the props, but do have the cam skills to create the part from a solid model if it were supplied to me as has been done on my cnc router at home.
Which leads to the next part, if you do not make the cad models yourself, then in reality, you have just copied a part and got it produced which is essentially my cnc made carbon props.
|Thread: Accuracy of cheap ER collets|
There was a chinese made sets of ER32 collets about 2-3 years ago and they were just terribly made. The front 30 deg taper was not concentric to the 8 deg taper. The other issue was the groove was cut too shallow for the collet retract. It may be possible that you got one of these collets or one with similar problems.
I have learnt that cheap is just wasting time and money if you are expecting any level of precision.
|Thread: super glue|
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.
|Thread: Rc 45-50|
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.
|Thread: Polishing Brass - or where to get P5000 paper|
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.
|Thread: A very accurate lathe quick change tool holder|
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.
|Thread: Problems with newly purchased indexable tip cutting tools.|
This is the UK site, The inserts I use are these, Kyocera CCGT060202MP-CK PR1425
Product code TKD01307 PR1425
A better picture is here,
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.
|Thread: J-B Weld not setting|
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.
|Thread: Dickson type T00 toolholders|
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.
|Thread: sieg sc3 mini lathe precision ?|
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.
|Thread: Secrecy...within the workshop?|
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.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.