By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Mike Crossfield

Here is a list of all the postings Mike Crossfield has made in our forums. Click on a thread name to jump to the thread.

Thread: Cutters
30/07/2019 14:40:39

Ken

I make all the wheels (and pinions for that matter) for my clocks using home-made cutters. I use a variation of the “button” method to make the cutters. I start out with a cutter in the form of a parting tool ground to an accurate width with a semicircular tip. I use this to cut the wheel/pinion cutter from round silver steel. The centre fixing hole is offset to create cutting clearance. After parting off, a segment of the disc is removed to create the cutting edge, and the cutter is hardened and tempered. Then away you go. Brass wheels are easy to cut in a single pass with the mill running flat out (2000 rpm). Steel pinions are harder, and I typically take 3 or 4 passes running at 200rpm, and using lots of cutting oil. I get all my cutter geometry data from the very useful table in the Meadows and Passmore catalogue

Examples of a wheel cutter, a pinion cutter, and some wheels and pinions cut for my latest clock are shown below.

89927d99-3b6c-409d-bf0f-d0832df033c1.jpeg

367a10ad-fa3a-4108-8c23-7966e5549d39.jpeg

bbb1b0f6-3b2e-4494-916b-fdccdbb6dedd.jpeg

Thread: Up and over door seal
30/07/2019 11:51:01

I have a strip of the damp proof plastic membrane that bricklayers use fixed to the bottom inside face of my up and over garage doors. I used self tappers and washers to fix. Very flexible, weather-proof and cheap as chips. Works a treat for keeping out wind blown rain and leaves.

Mike

Thread: ML7 lathe carriage
30/07/2019 11:42:01

I dowelled the saddle gib on my early Super 7 about 20 years ago after reading an item by either GHT or Jack Redford. It was certainly an improvement, and allowed the gib to be set very closely without tightening up when the saddle was moved. Interestingly, Myford changed the gib design on later models so that one of the screws provided the equivalent of a dowel function. However I don’t believe this was carried across to the ML7.

Mike

Thread: What method do you use to find center height for your lathe bit?
27/06/2019 07:26:09

20-odd years ago I made George Thomas’ centre height gauge. Very nice design which can be used from the bed or the top of the cross slide. I use it all the time and can highly recommend it.

Thread: Sino SDS-2MS Dro problems
13/06/2019 14:34:07

Alan

Yes, I did sort it out. What I found was that when you enter the PCD Function and the CT POS display comes up you MUST enter values for X and Y, even if they are both zero and the display is already showing zero. You can’t just press enter and move on to the next setting. To be fair it does show this in the manual (steps 3 and 4 in the version I have), but it wasn’t clear - to me at least - that you need to enter zero if the display is already showing zero.

Hope this works for you too.

Mike

Thread: What are you using for Lathe Way Oil?
02/06/2019 10:58:43

I use 68 grade Slideway Oil. As with all my lubricants, I buy it from Smith and Allan. Great service and low prices. 5 litres Slideway Oil is £11.55 plus vat and carriage. 5 litres lasts me 5 years+. I try to order a number of items (Slideway oil, cutting oil, spindle oil, paint etc) at the same time to spread carriage cost.

Thread: Electronic Indexers - How Is Cumulative Error Avoided?
30/05/2019 13:43:58

I built Steve Ward’s excellent design of controller a few years ago. Very well documented and simple to build using a programmed PIC and pcb available from Steve at very low cost (Full kits also available). Regarding William’s original question, Steve answered this with respect to his own design in response to someone else’s question a few years ago. I quote:

“So basically internally it multiplies the number of divisions by the actual division its on then divides the result by the number of steps for a full circle - this gives it the nearest number of steps it needs to get to that division (doing the multiply first prevents loss of resolution although it means it needs 32 bit maths which is why the max steps per rev is 16 bit).
Internally it knows exactly how many steps it's currently taken so simply adds (or subtracts) that from the answer above to get the number of steps to take.

This means there isn't a constant number of steps since it may need to take an extra step (or lose one to be accurate).

In practice the accuracy of the maths is half the single step resolution, so a 400 step driver on a 90:1 worm gives you 0.01 degrees per step so the accuracy is 0.005 degrees. (Mechanical accuracy not withstanding)”

HTH

Thread: Rusty Clock Springs
30/05/2019 11:00:55

“The guy on the TV is an idiot”

That’s a bit harsh Bazyle. I saw the programme mentioned, and what the chap said was that people often say a clock has been “overwound”, but that’s often not the problem, and one would have to really strain on the key to do damage. Sure, springs can break in normal usage, but the comment was not unreasonable. And from the apparent quality of work that the man in question does, and his 40 years experience of clock repairs, he should know what he’s talking about.

Thread: kerry super 8 bench drill
26/05/2019 11:57:16

I have a Kerry Super drill which I bought and renovated about 20 years ago. It was in a pretty neglected state, but cleaned up well and I would never part with it. There is a photo in my album, but unfortunately it doesn’t show the side with the return spring housing. When I got the machine the original return spring cover was missing, but fortunately the clock-type spring was still there. I turned up a new cover out of ally, and it’s been fine ever since. The inner of the spring fits into the slotted end of the quill operating spindle, and the outer end fits into a slot in the cover. The cover is a shallow “cup” which the spring sits in, rather like the barrel of a clock. To tension the spring the cover is rotated in its housing in the drill casting, then locked with a grub screw. No drama taking it apart. Just release the grub screw while holding the cover and release the tension. The cover can then be pulled off complete with the internal spring.

Mike

Thread: Stand alone controller
19/05/2019 09:13:20

Gray

if you search on eBay for “3 axis stand alone stepper motor controller” you will find several Chinese suppliers.

Thread: Ever have one of those days..?
15/05/2019 10:37:37

As the old saying goes - "the man who never made a mistake never made anything".

Mike

Thread: Myford Clutch Lever fouls the Belt Cover
13/05/2019 18:32:44

My late 50s Super 7 is the same as John’s, the belt cover rubs on the lever if it’s opened in the “engaged” position.

Mike

Thread: Milling Brass
06/05/2019 19:05:56

That’s interesting. The reason I asked was that a rule of thumb I was given some time ago was a chip load 1% of cutter diameter. This this has worked out ok for me in the past. For a 2 mm cutter that suggests .02 mm, just under a thou.

06/05/2019 17:54:26
Posted by JasonB on 06/05/2019 17:16:15:

Just had a quick look at Sheetcam and it looks like your tool will just be following around the outside of the shape to produce the profile so you will be cutting at the full 2mm width.

I would say to be safe go 0.5mm deep per pass, 3000rpm with a chip load of 0.005mm so that gives a speed of

3000 x 0.005 x 2flutes = 30mm per minute

Jason. That seems to be a very small chip load. How do you arrive at that figure?

Thread: ML7 Carriage shims and wear
03/05/2019 18:48:56

The correct shims are made up of a laminated stack, each individual shim being 2 thou thick. To reduce the thickness, and remove play, shins can be peeled off the stack with a sharp knife. It could be that the previous owner has removed too much, and compensated by leaving the clamping screws loose. You could buy new shims, but I would be inclined to try adding some extra shim material until you get the required clearance.

Thread: The Chocolate Fireguard as designed by Mercedes Benz
27/04/2019 09:31:16
Posted by Mark Rand on 26/04/2019 22:48:50:

Since everyone seems to be having a moan. Can I complain about the ever increasing number of complete arseholes that don't use their handbrake when stopped at junctions and traffic lights, but keep their foot on the brake pedal. Thereby shining their head-level brake lights into my face! angry

I was taught to take the car out of gear and apply the hand brake if stationary for more than a few seconds, and regards it as sloppy and inconsiderate driving to hold the car on the footbrake. However you do see it quite a lot, particularly with young drivers. Maybe something to do with the way they are now taught? Another issue is that some modern cars (like my latest) have an “auto hold” or “hold assist” feature which keeps the brakes applied hydraulically when the car is braked to a stop, so no need to apply the parking brake in temporary stopping situations (these cars generally don’t have a conventional manual hand brake). The consequence is that the brake lights stay on, even though the driver does not have his foot on the brake. When I discovered this I found that I could over-ride the Autohold by applying the Electronic Parking Brake, thereby turning the lights off. Interestingly, from threads on motoring forums I belong to, quite a few users aren’t aware that Autohold leaves their brake lights on. This ought to be made clear in the Manual for the car, but it isn’t. I have it on good authority that the salesmen at some main dealers don’t know about this either.

Thread: How to get that high end paint finish
13/04/2019 13:14:30

Definitely invest in a better brush. I use Hamilton Perfection Pure Bristle. Less than a tenner on eBay for a 2 inch, or you can get a set of 4 different sizes for about £25.

Thread: Dialect expressions
13/04/2019 11:37:07

I spent my early childhood in the North West near Bury, and many local dialect terms abounded. One which springs to mind, and was capable of dangerous confusion, was the use of “while” to mean “until”. Example: ”wait here while I come back” meaning wait here until I come back. The story goes that a “southerner” working in a factory boiler house was told “don’t light the boiler while water’s in”. The consequences were predicable!

Thread: How to get that high end paint finish
13/04/2019 11:21:16

Rainbow

Your preparation sounds good, though you don’t say how you rub down between coats. For the very best finish I use 400 or 600 grit wet and dry paper and soapy water between coats to remove minor imperfections and brush marks. Use a cork or rubber backing block where feasible. As has been already said, a really good pure bristle brush of the right size makes a big difference if you’re applying by hand, and a slow drying paint will make it easy to keep a wet edge and allow brush marks to flow out. I’m a big fan of Tractol paint, which is capable of excellent results when hand applied, and is tough as old boots. Even better if you have spraying facilities.

Thread: Sending of heavy items
08/04/2019 11:44:17

Do check carefully when looking at courier delivery costs. I recently shipped two items, one 7kg, the other 14kg. In both cases the initial prices that popped up on Parcel2go looked very good £8 and £9 respectively. However insurance for £200 more than doubled the cost, then VAT added another 20%, so final costs were £20 odd.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
TRANSWAVE Converters
Eccentric Engineering
Advertise With Us
Meridienne Sept 2019
ChesterUK
Eccentric July 5 2018
Warco
Ausee.com.au
Allendale Electronics
emcomachinetools
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

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.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest