Member postings for Adrian Rawson

Bought this yesterday at an emporium. Fits the Myford and works well. Didn't know they existed.

Edited By Adrian Rawson on 20/06/2021 15:46:52

My article in MEW was pitched as a taster to invite feedback from the readership. My intention was always to give much more information to anyone who showed an interest. As you can see from the linked documents it would have required a series of articles to complete.

Although the divider works as specified, it's still an ongoing project for me. I'm currently looking at a closed loop stepper motors with the possibility of improving the accuracy and reliability. I'd also like to include a clutch on the worm drive to obviate lockups. Oh! and a cast aluminium body which is currently beyond me.

A new stepper motor is on order from China and I'll use this forum topic to document any progress.

Thanks for your interest.

Thanks Neil, sorry it proved a bit difficult.

I've sent a load of detailed documentation to Neil who will link it to this thread ASAP. It covers the mechanical build the electronics build and a software user guide. Hope this helps, and thanks John for your interest.

Tried and tested a headstock mount for the divider. Used a 2MT collet connected to a mandrel extension. Then fixed a printed plastic bracket between overarm and stud gear to hold divider in place. Shown under test here **LINK**

Finished making a headstock mount for my divider project. Suffered a bit of grief from a home made 'Myford' collet but managed to get it tight enough to make this video **LINK**.

The mount, as designed, requires the lathe to have a quick change gear box as it relies on the stub gear as a fixing point. I couldn't find any where else to hold the divider firmly in place. The bracket with holes in is printed plastic. I made the mandrel extension with plenty of steel to fix the 'driving' collet to. Now I must make a handle for it to extend its usefulness.

I meant to say drive the head stock directly - sorry. Anyway here are photos of the current worm drive and electronics.

Brian is right, a Raspberry Pi is overkill, so since submitting the article to the magazine I've changed the brain to an ATSAMD device which is smaller and starts up much more quickly. Also it gave me the opportunity to modify the software quite a bit. I've also changed the worm gear to a heavier 30 tooth setup, which with a 400 step motor gives the same accuracy as before. I'm currently working on a mount to enable it to drive the tail stock directly.

It's a stupid thing but when I was at school I calculated how many seconds there are in century (assuming 25 leap years) and although I no longer remember what day it is I still remember 3,155,760,000 after 60 or so years. When I did the calculation it seemed like a long time but now I'm over half way there. If the number's wrong please don't tell me (there were no calculators then).

Tried this out today. Seems to work and hope it's improved things..

A bit late on the scene here, but I also need to grind my chuck jaws true. All the advice made it clear that the jaws should be loaded during the operation. I looked around for availability of a Hopper's clover leaf plate but found nothing. Should I make one? Then I was inspired by Alan Jackson's solution, but accepted it must be a bit fiddly to set up. Clearly the jaws needed to bear on their angled faces allowing the 'bite' surfaces to protrude for grinding. Decided to try a design in plastic. No milling or drilling, just a bit of 3D printing. The plastic takes quite a load without any distortion. Oh! and the mount for the Chinese Dremel is plastic too. So before I spin things up, can anyone see a problem with this set up?

Brilliant! It's so obvious now. The words swing clear and swing back gave it more meaning for me. I just sat it on the lathe cross-slide to have a look at how it would work. Thanks

When I bought my second hand lathe some years ago it came with lots of useful stuff, but one item that I have never found a use for is pictured here. Any ideas what it is?

My Myford Super 7 has Tufnol tumbler gears. I wasn’t really aware of this until a loud bang emanating from the gear train required investigation. I was trying to cut a 9 TPI Acme worm for my Divider project (MEW 295), and because I was waiting for a delivery of EN1A steel bar, was experimenting with a bit of stainless I had kicking around.

The Tufnol gear had lost three of its teeth. A quick search on the internet revealed some imports made from Tufnol rod and not recommended, or a supplier in the Netherlands who charged £20 for delivery.

Before I made a decision on parting with cash I decided to investigate why I’d had the problem. I read that the Tufnol gears are there to act as fuses that ‘blow’ under excessive loads. I checked out the lathe and everything was running fairly smoothly. I then read somewhere that making light cuts on stainless causes it to work harden. The tool I was using was a home made form tool, and I guess it grabbed and locked the lathe up, but I wasn’t sure.

I knew the next thing I did wouldn’t work but it cost nothing so I printed a 30 tooth gear on my 3D printer. This had the advantage at least of giving me a dry run on strip down and reassembly of the tumbler mechanism. The gear ran quite well until I put a light work load on it. I guess you shouldn’t use a 3 Amp fuse on a 40 Amp load.

The lathe was out of operation and I had a worm to make, but I couldn’t bring myself to send £50 plus to Norway. So I decided to buy some Tufnol and make my own gear. I spent £30 on a 300 mm square by 10 mm thick Tufnol Whale sheet from Direct Plastics. After a couple of attempts at making a decent fly-cutter, I managed to make a half decent 30 tooth gear which has now been in use for a couple of months. Did I make the right decision? Maybe not, I’ve just checked and the Myford site is now offering this item for £20. But should the fuse blow again I’ve enough Tufnol to make quite a few more.

I've done lots of Raspberry Pi stuff and recently CircuitPython on Adafruit ItsyBitsy M4 using OLED and ePaper displays but have never come across this Nextion solution, so thanks for the post. Having had a quick look at their site it would appear that the editor is PC only. Maybe by the time I need to use one they'll have a Java solution that will run on a MAC.

A closet engineer interested in everything but no expert in any field. Basic workshop centred around a Myford ML7. Lots of experience gained in 3D printing using OpenScad. Working life spent in computer hardware and software. Recently returned to the UK from fifteen years early retirement in Italy. My design for a computerised divider just featured in the mag.