Member postings for Neil Lickfold

For longer knurl lengths, I normally start at the chuck end and finish at the tailstock end. I normally use coolant to wash away any micro bits of what ever. At the start I wind back and forth for about a roller width to see that I am happy with the depth or definition of the knurl then cut down the length. I normally run quite a bit faster than you did, around the 200 rpm range on steel that diameter. Sometimes the knurl does not quite work out due to the pitch of the form not matching the diameter. A bit like gears. If the diameter is too big the top of the teeth become very pointy. If the diameter is too small the top is very wide. I normally just hand feed the carriage when knurling.

On mine I scraped the bed back to being parallel and used a micrometer to measure my progress. The saddle looked fine and made no changes to it. The tailstock needed to be adjusted due to the now wider slot and of course needed its centre line position to be corrected. It took a long time to hand work the bed and probably needs redoing again at some point as well. It was around 1997 when it was fixed. I have since added a gravity oil feed system to the lathe to keep oil between the saddle and the bed to compensate for the bed wear towards the headstock. Since doing that, it has been much easier to get very consistent results. I have been thinking about building up one side with thin turcite strip, but that stuff is very expensive and from what i have seen the thinnest available may still be too thick. Mine was not as badly worn as your one. The bed was about 0.1mm of metal removed from the thickest part. And it seems that the thinnest turcite is 0.8mm thick. So have to give it alot more thought. I just don't recall the amount of adjustment that is in there. I do wish that I had taken notes or pictures of what I did at the time, but didn't because I just needed it back together to be making some model engine parts. Funny how you think that you will remember at the time though. Micrometers are not that expensive either these days, and as it is more of a comparator than an exact measurement that is needed, any micrometer will make the measuring easier than No micrometer. Mine is about the same vintage as your one by the sounds of it.

Good luck with the restoration, and will be nice to hear what you decide on doing to repair it.

I have had a very good run with Insize digital calipers . I got some about 6 years ago now, and are still just fine. I recently bought a smaller 4 inch set to use, instead of the 8 inch that I got 6 years ago. Just makes it easier to check things on the lathe or mill. If I need to be more accurate than 0.04mm on length or diameter then use different measuring equipment. I manly use them to check that something is not grossly wrong, ie 1 turn short of a dial somewhere etc.

Neil

The best ones are water jet cut from spring steel stock. The petal thickness depends a bit on the fuel being used as well, so some have 0.006 inch, 0.007 inch and 0.008 inch thick spring steel petals made. The hobby king petals work quite well for the standard or the sport jet class to 150mph or so. To go faster requires testing with other material thicknesses and keeping records of the  day temps and humidity. 

Laser cut ones are not as fast as the waterjet cut ones . It maybe due to the very small heat distortion from the cutting of the petals from the laser.

Neil

Edited By Neil Lickfold on 11/12/2021 00:36:11

What I do like about mechanical micrometers is their are no batteries to leak and fail the tool. In saying that, I recently did buy a digital depth micrometer, for the purpose of using it like a comparator. I don't think it matters all that much , if electronic or mechanical, as long as you can make the parts you want to. Gauge block sets are in the very affordable range now, with many coming with a certificate of accuracy for each block. So with a good set of gauge blocks and repeatable measuring equipment, new cutting tool technologies, now more than ever, allows home users to being able to easily make interchangeable parts.

I heat the O1 and gauge plate to hotter than bright red, it is actually an orange colour and allow time for the heat soak etc, then Quench in oil. You need quite a lot of oil, as if the oil heats you will loose it's peak hardness. Getting 63Rc is normal hardness range. This is how I did the hardening of my outer ball bearing races for a bearing that is no longer made.

Using a high tensile steel like 4340 or the similar high tensile will last a life time. When milling the flats, I suggest using the side of the cutter , as it creates a nice radius in the corner. If you use a #2 centre drill, but shorten the front of the centre drill so it only has 1mm or so parallel section before the 30 deg taper starts. Then you can use the centre support o=if need be when milling the end. Keeping the inside of the square drive of the chuck very clean will make the new pone last a very long time. I suggest that you make one with a T type handle for final tightening up, but be aware of over tightening on the jaws. The other I would suggest is 2 more but shorter in length and with about 30mm or so round handle for adjusting two opposite jaws at the same time for a quicker indication of parts. The shorter 2 can be made even from mild steel as there will not be a great deal of torque applied to these smaller ones.

Neil

Does your lathe have the threaded nose, or the Taper nose on the lathe main spindle.

Toyota had to secure the mats in my car after an event where the floor mat kept the accelerator pedal depressed. I was told that the car was fitted with after market floor mats and Toyota was not responsible. I pointed out that the driver side mat had the official Toyota emblem on them . Toyota NZ did a recall on my model car where they supplied the mats with the retention pieces to stop it sliding forward and ever jamming again.

I have had recently a few rpm where the chuck at work , looks to be slowly turning backwards. It never happened when I had the pair of fluro tubes above the machine. But they got replaced with a pair of LED replacement for the twin fluro tubes. I talked to my son about it, and he said most likely, all the led's are turning off and on again with the frequency of the AC current. He explained that the leds are flickering like a single incandescent light. I took my Futaba optical tacho to work and it shows 3000 rpm, or 50hz reading. He said most leds will have a frequency that they work at, even driven from a dc source. So I tested our led torch and it varies from 25hz to 60hz . My wifes phone led shows no frequency however.

At home I have above my S7, the 5 foot LED equivalent of a duel fluro light. It is positioned so that the front lamp tube is on the centre line of the lathe . I have no shadowing to speak of. I also have an lep lamp on a flexi neck, for looking down inner bores. It sits inline with the tailstock and is about 1/2 a m back, so not in the way. It gives me more than enough light for everything. I only run in the low speed from the motor to the clutch, so max is like 700 rpm or so for anything I make. Any frequency of the light issues I have never noticed in my home shop.

I like the Hardinge style of setting the top slide at half the thread angle. You move the cam, the tool retracts. While it is going back to the start, you can wind on the next cut with the cross slide or just use the topslide infeed dial until you get to full depth. On my Myford I like the 1/2 thread on the top slide method. It allows for more room when a piece needs to be supported by the tail stock for example.

Some DRO installations are better than others. Some are installed with long extensions from something not very solid ,using a collection aluminium brackets. These I have seen can cause issues. The solution was to use a shorter steel bracket and that got rid of the errors that were occurring with the short travel back and forth. Like when you wind on or off by less than 0.2 mm of stroke. In the case I saw, wound clockwise, then zero. go past and wind back, and the reading was still zero, but the indicator reading was 0.03mm out . With the shortened steel bracket in place, no detectable error was measured using normal shop indicators or tools.

I have never seen an on size carbide milling cutter yet that is made from the nominal carbide stock. Off sized cutter I have seen are on size or sometimes marginally over sized, like a 9mm cutter on a 10mm shank, or a 5mm cutter from 6mm stock.

Most places will take cuts measure , then compensate accordingly.

MichaelG I was only quick on that , as where I work, a lot of parts are designed using the PCD for the hole spacing. Particularly when a sheet metal part was needed to be made by marking out. Sadly that designer has since passed away, but a lot of his drawings crop up from time to time along with the old tools to be repaired. Most modern stuff is just XY coordinates these days, if you are lucky, otherwise it is all left on the 3d model of the part. Using basic hand marking out tools the PCD or the PCR method is very easy and effective with quite remarkable results being achievable. I find it interesting to being able to turn finished pistons on my old Myford lathe, that most need to lap or do some other method. I only have the digital depth on the tailstock, otherwise, everything else is all old school of winding handles or dials at the right amount to a clock ticking.

What I forgot to say is, that these new very sharp tools that are available today, allow such precise cutting that was very difficult to achieve in the past. There are very sharp PCD inserts that will allow sub micron cutting in stable non ferrous materials. The carbide inserts will allow 1 micron to be taken as a cut off steel. Granted these are not easy to achieve , but are possible in the right conditions. Some of the new coatings are designed to be used dry. No coolant at all, which I find very interesting in itself, and also handy for the home shop at the same time. The latest insert technology is not priced in the unaffordable range either, generally in the same range as the previous coatings etc. Like the new ccgto9 inserts are still at $18nz for the new coating insert that now lasts longer than the previous coating inserts .

MichaelG In your example it is 2-5/8 PCD

Well old fashion toolmakers who know how to refit new parts to a hobbed or used part are very thin on the ground now. The young ones make the part to the cad model, but have no idea about making it fit and bluing in the parts.

There are new grades of carbide coming out all the time. The latest ones are very sharp and are extremely good for finishing and you don't need high surface speed or high RPM to get a good finish. I don't use the high speed range on my S7. I have a TNMG holder, the only negative holder I use. But use the positive inserts for that holder. Ones for steel and ones for aluminium. Lately I have been using what is sold as a wonder insert out here. See .my album. They work very well. There is a new range of ground coated inserts that are very sharp and are excellent for roughing out as well. When they dull from finishing become roughing inserts. The CCGT09 and the CCGT06 inserts I use in my boring bars and external turning tools. The DCMT11 is only for the outer turning. Here in NZ quite a few of the tool companies will sell one or 2 inserts to the home hobbyist. I only use HSS for form tools that are for a specific project.

Cheapy tools can sometimes turn into an apprentice training exercise over a few weekends to fix properly. Sometimes you just end up with the hardened or the more difficult parts to make, and then completely remake or find some other way to make the tool to be functional as intended. Sometimes things need spacers, or clearances for pivoting , or pivoting washers, etc

For precision and nicely ground hss I use a white wheel stone. In a hurry I have used a linishing wheel to blank out a form, but finish with a hand lap stone or a fine white wheel.

That gauge is not going to show you what bearing blue will. The seat will be ground off the guides anyway. Being a 1 thou resolution , is very course for concentricity for valve guides to valve seats. I don't understand how you can't see if a seat is not evenly ground, sorry.