Member postings for Mike Crossfield

Well, according to your diagram the length of the tapered section is not 17mm. The dimension 17mm includes a parallel section. For an 8 degree taper with a difference in diameters of 3.5 mm, the taper length would be 12.452mm. Incidentally, half 3.5 is 1.75, not the 1.725 you show.

Hth

Mike

20 tooth gear should be 24 tooth.

I can heartily recommend Colin Thorne’s book Clockmaking for the Model Engineer as an excellent inexpensive beginner’s guide. This also incudes a simple clock design. Next step up would be Colin’s Simple Skeleton Clock, The book and the plans for the skeleton clock are available from Ian Cobb’s comprehensive website Clockmaking-brass. co.uk.

hth

Mike

I made a couple of ER25 chucks from mild steel about 15 years ago, one for the mill and one for the lathe. They get a lot of use, but they are still going strong and remain accurate.

It’s well worth while paying a bit more and buying ball bearing nuts. The tightening torque for good grip is considerably less. Particularly important in the mill, where I’ve never knowingly had a cutter slip.

Mike

That’s great!

Thanks to everybody who replied. I am sure I can now get what I need.

Mike

I need about 3 inches of 1 inch OD thin wall stainless steel tube (for the displacer piston of a Sterling engine). The usual ME suppliers don’t stock diameters this big, and others I’ve found only supply in long lengths and/or add on hefty carriage charges making it very expensive for what will be a one-off requirement.

Can anyone suggest a reasonably priced source?

Thanks

Mike

Andy

if you give your location it’s likely that a local forum member could visit and help identify what is there and give you an idea of values.

Double post

Edited By Mike Crossfield on 12/07/2022 22:30:57

Andrew

According to the technical blurb for my car, the battery management system controls normal charging so that it never charges the battery to more than 80% to leave headroom for regenerative charging. The system does seem to be pretty sophisticated, and, for example, if the battery charge is getting low, or drain is high, it progressively shuts down power consumers so that essential items are kept going as long as possible. It also adapts to allows for battery ageing. One complication is that when the battery is changed the relevant ECU has to be reprogrammed with the details of the new battery or the charging characteristics will be non-optimum. So unless you have the necessary software, a simple battery change turns into an expensive visit to the dealer!

Mike

0n my car (newish Audi, but I imagine it will apply to a lot of modern cars), the current flow in and out if the battery is monitored by a module connected between the battery negative lead and the chassis. This is part of a sophisticated battery management system which includes recharging from regenerative braking. If you connect a charger directly to the battery terminals you bypass the current flow sensor, and allegedly confuse the system. A special chassis terminal is provided for battery charger connection. On my car this is right next to the battery, so no lower explosion risk than a direct connection ti the battery terminal. Incidentally my smart charger can’t be enabled until the leads are connected to the battery, and the power is shut off if the connection is intermittent, so In theory no risk of a spark. I imagine the CTEK is the same.

Mike

Very impressive. Superb workmanship, and model engineering of the highest quality.

If, as seems likely, the items are going to be exposed to the weather, the only real solution is lacquer. I can recommend Incralac. This was developed specifically for copper based alloys. A bit pricey, but good stuff. Available in tins or aerosol cans.

Mike

+1 for CTC. I bought from them a while back when they only listed on eBay, and had good experience. At the time the company was run by a German based in China, and I was pleased with the products and the service. When I wanted an extra collet which was outside the range normally supplied he was very helpful and supplied what I needed at very reasonable cost. Collets I bought all seemed to be within the stated DIN spec. on runout.

Mike

I haven't got round to trying it myself yet, but Ferrosol from Bilt Hamber gets some very good reviews. Seems to be much more than just a penetrating fluid.

https://bilthamber.com/product/ferrosol/

I have used several Bilt Hamber products, mainly on the car, and they have all been excellent, so I would be surprised if this wasn't good as well.

Mike

Lathespares stock saddle gib adjusting screws for certain Super7 models, and there are pictures on their website.

https://www.lathespares.co.uk/myford-super-7-saddle-adjusting-screw

hth

Mije

Eliza,

Where are you located exactly (nearest town)?

Mike

+1 for a dehumidifier. I use one in my unheated brickbuilt workshop (concrete floor), and I never see any rust. Cheap to run set to 70% humidity, and even generates a little heat. My wife also appreciates the endless supply of “distilled” water for her steam iron. I bought mine secondhand on eBay 10 years ago - best £30 I ever spent.

By coincidence I just noticed that there is a Fobco Star drill for sale by Bede Machine Tools, advertised on the HomeWorkshop website. Looks decent enough in the photos. £275, which is more like the sort of price I would expect, and pretty good for a trader. Even includes a drill vice.

My view is similar to that of Martin King. £700 is top money for a machine like this, the sort of price you might expect to pay to a dealer. Privately you might expect to pay half this price. I would also prefer a machine with a rack to raise and lower the table.

Mike

In his book "A Model Engineers Workshop Manual" G H Thomas discusses similar devices (page 27) and describes a neat design. I made one 20 odd years ago and use it from time to time. Like all GHT designs, it works beautifully. Could be made in an hour. GHT mentions that a commercial device used to be made by Starrett.

Mike