Member postings for Neil Lickfold

Muzzer, you can't get it to ultra sonic weld properly with virgin material. Like the Styer gun buts, they were nylon with a glass fill. There was a run that they could not weld. The fix was either to use a solvent with the ultrasonic welder , or to use a percentage of reground material in the blend. It was discovered by mistake and then used from that point on. So the 1st lot of mouldings went straight into the grinder, specific for that machine and material. The solvent and ultra sonic welded ones were not was strong as the ultrasonic only welded ones that used the regrind blend. Needless to say, the mould were cleaned of any mould saving product before the run, and a ban on any silicon spray or release spray that contained silicon in the are and vicinity of the machines. There are loads of different types of nylons these days and nylon filler blends. But all nylons are hygroscopic.

Neil

Commercially, Nylon needs to go through a dryer before it can be pre heated and then melted in injection moulding machines. If it requires to be ultrasonic welded afterwards, then it requires that there be about 20 to 25% reground material also feed into the system. It will in high temps and high pressures go through very small gaps. 0.01mm is considered a big gap in Nylon injection moulding tools. Typically venting is in the 0.003mm range .

Neil

Commercially, Nylon needs to go through a dryer before it can be pre heated and then melted in injection moulding machines. If it requires to be ultrasonic welded afterwards, then it requires that there be about 20 to 25% reground material also feed into the system. It will in high temps and high pressures go through very small gaps. 0.01mm is considered a big gap in Nylon injection moulding tools. Typically venting is in the 0.003mm range .

Neil

We saw something similar in Zelienople Pa, 2 days in a row in the late afternoon. Never had a camera though.

Thanks for sharing the great picture.

A2 is preferred because it is a dimensionally a very stable steel . I use oxy acetylene for the hardening and a home oven for the tempering on fanbake. Small parts may be heated with a propane torch.just not sure, it needs to get to bright red heat to a very dull orange at the very hottest. With A2 as soon as you have it heated, keep it at temp for a minute or 2 then take the toch away and blow down cool with compressed air. With A2 steel you can drill it heat treat and then lap to size if required. 4340 and other steels are not as stable, so will require turning between centres or grinding. Some people use O1 or silver steel, some also use case hardening steels like EN36A or EN39B. Case hardening is a little more difficult to do at home. O1 and silversteel and 4340 can all be used at home. My 1st choice is A2, 2nd will be O1 steel, both double tempered. Silversteel is way down on my list with 4340 or 4130.

To get a really good service life, the pin needs to be micro polished as well. So it will look very shiny with no scratches , so will look like a needle roller bearing.

Drilled out Needle roller bearing needles also make good gudgeon pins as well, but need carbide drills.

Neil

Patrick I sent you a PM, I live in Hamilton.

Neil

I have since added some more hold down clamp holes and more dowel holes. The new holes were done in position after the plate was put in place.

Ian, That is why I made a sub plate to hold the vices with. The new ones have a sping and are very user friendly. I have never had the bottom nut come off yet at all.

Neil

For my cnc router , I brought a pair of Toolmakers vices, similar to what is listed , but from a local tool company. They are within 0.01mm everywhere to being the same. I mounted them onto a sub plate that has dowels to located the vice to. 3 pins , 1 is an end stop, and the other 2 are a side stop. These are spaced so that I can have the vices 25mm apart to a max of 200 mm between the 2 vices. The dowels are a neat slide fit for the side pins, so can be removed if required. I'm very happy with them so far and it's been 2 years now. The new vices all seem to have the short retaining pin that can be loosened off and then slide to the next hole point. The older ones used to have a through dowel that needed changing and that really was a pain at times. I used M8 capscrews for the end clamps, so the 6mm allen key does all the clamps and the vice jaw tightening. Mine also has M8 threaded holes for the side stops etc as well.

Neil

McMaster Carr sell the drill rod stock. Here is a link https://www.mcmaster.com/#tool-steel/=1awo5pi

A2 tool steel should be available or the equivelent, but not sure what that number is from any tool room supply company. Most commercial places that do the air hardening of the A2 steel do son in a controlled atmosphere and so it comes out looking a nice purple sort of hue. Normally it will be centreless ground after but can be cylindrically ground and if there are centre's can be hard turned between centres. So lots of options. For hard turning, Cermaic inserts work very well in the 0.4mm radius range and so does CBN inserts in 0.2mm radius range. The CBN actually has a slightly higher cutting force over a Ceramic insert, but a 0.2mm radius CBN is slightly less cutting force than a 0.4mm Ceramic. I have not seen for sale 0.2mm radius ceramic inserts, or else I would be buying them. You can heat treat the A2 tool steel yourself quite easily at home with an Oxy Acetylene torch and some compressed air to quench from very bright cherry red. But not Orange. Then temper 2x at about 160c should bring them back to the 60Rc temper range. 180C is getting on the hot side and 150C is on the cold side. Polished before tempering and free from oil, they will be a very light straw colour. Light brown colour is on the softer side.

Neil

A2 tool steel makes for great wrist pins/gudgeon pins. Harden and double temper to 58 to 60 Rc. H13 hardened to 50Rc and Nirided also works quite well, but A2 would be my 1st choice. Not sure if you are going for the press fit to the pistons or the fully floating set up. You want less than 0.01mm diameter clearance for a floating wrist pin and piston fit. For the retaining circlips and pin length, ideally you want no mare than 0.03mm of total end float between the pin and the circlips.

Nice project and thanks for sharing.

Neil

I use now mostly rice bran oil from a spray can. Castor oil I still use for tapping, but does leave a nasty gum to clean up from if not cleaned with meths or some other solvent. SO now clean up more often as these oils tend to go gummy over time. Soluble coolants get into the slides etc and I feel is the main cause of wear in machine tools. Machines that have cutting oil coolant, tend to last a lot longer and in better condition than those machine that use water based coolants. Castor is great for tapping holes and I find the tap and reamers cut closer to size with castor oil over anything else I have tried over the years. I buy the degummed castor oil from model/honny shops for those that make their own fuel. I don't get the castor and synthetic mix.

Neil

The MT2 is taper per foot. It does not need to be the full lenth to be effective. It can be still effective even if the taper section is only 50mm long. You want the tool on centre to about no more than 0.05mm above centre. Do not have the bore bar below centre at all. Using bearing blue to check it also works very well. If you are out by 0.01mm in 50mm it will not make that much difference. It will stil work and need a drift to remove it .

Neil

In reality, this is 3d printing a sintered item. It really is not the same as a 3d printed metal part that has beed printed with an electron beam that fuses the layers together in real time. But the technology is movingvery quickly with new ideas it seems monthly. I know that many are working on ways to mimick the over casting methods, like when a steel or cast iron part has a cast Al alloy feature as part of the whole, or when metal inserts are cast over with alloys. The last level will be the combination of metals and ceramics , especially for parts that are exposed to extreme heat, like in a rocket engine.

Neil

The real advantage of having a T&C grinder or a D Bit grinder, is being able to make cutters for a specific task. To buy these special cutters, is very expensive in deed. Certainly many years ago, we used to sharpen endmills with a taper on them, so that after the pass down the face, it was a vertical face.Those were the days. Now days most would not know how to make a correction ground cutter. A comprehensive T&C grinder will allow you to make the cutters from solid stock, no matter what the cutter is. You do spend a lot of time in setting up though that is for sure.

Neil

What do you consider to be a tight tolerence? What talking about indicators, are you also talking about micrometers, and digital calipers as well? Or are you jst talking about diat test indiactors? With dial test indicators, the rigidity of the stand holding the indicator can have an effect on the value that you are able to measure. The smaller the units you are measuring the more difficult the task of measuring becomes. If you are talking about 0.01mm , that is very easy to measure compared to 0.001mm or 0.0005mm. Sometimes , when working to very tight tolerences, specific gauging is often made, to be able to compare these part sizes. Particular when you are making parts where the size to be acheived needs to be less than 0.001mm. In the home shop, making round things, is achieveable to 0.001mm but not when milling.

Use 2 keys with your 4 jaw chuck and they become very quick to use. For and Aft or on a diagonal like when using a myford. My second key is just a piece of key steel made to fit the chuck with about a 38mm -1-1/2 inch disc attached.I use 2 of these, and the final tightening is just with one key that came with the chuck.

Loctie 620 is a high temp high strength glue. Use it with their primer when gluing Al. Prime both parts, allow primer to dry, then apply the 620 to both surfaces, and assemble. It can have a gap to about 0.1mm or so on diameter. The larger the gap, the weaker the joint.

Neil

If you are buying a soluble cutting fluid, I buy the one that is chlorine free. Mainluy because from time to time I do turn and dril Titanium, either grade 2 or grade 5. On most things I just use the rice bran oil in a spray can. Was using canola oil but it does make a mess on the tools after a while. nasty to clean off too. If I am reaming holes and need a really nice sized hole off the reamer, I then use a mixture with castor oil in it. It will allow a hole to be reamed so close to the reamers size that the reamer becomes hard to pit back into the hole. I don't have a flood coolant system, only a suds botle for when needed.

Neil

Recently I have seen where a well known brand was being counterfiet in China and sold as this brand. The packet and label looks identical. The product looks to a casual observer as being the same. But a close inspection shows this is not the case. Not saying what you brought is a knock off , but it is happening. These knock off tips that I have seen don't have the tool cutting life of the genuine article. But home hobbiest seldom get the same cutting volume off an insert anyway.

Neil