Member postings for Bubble

Hi Katy

My access to the archive is also blocked, my subscription is until march2014

but the site tells me I am not a current subscriber

and yes my subs number is on my profile

Jim

Hi all

Google "Taperlite" spring

used on lorries and railway wagons

We fatigue tested them in BR Research years ago

Jim

Hi Lambton

This could be down to Google “targeted ads”

I found this about opting-out of this “service”

Log into your Google account and mozy over to the Google Ads Preferences page, where you can hit an Opt Out button to put a cookie (identified and detailed) on your system that blocks ad monitoring and targeting. The downside, though, is that any time you wipe out your cookies (a pretty common move, especially amongst the privacy-conscious), that preference washes out with them. So Google also offers an Opt-Out Preferences plug-in for Internet Explorer and Firefox that auto-kills ad targeting. Good for those who use those two leaders of the market; kinda annoying for everyone else

Jim

Hello All

Well last night rather than today.

Logged on to the ISS webcam **LINK** and the map of its current location **LINK** , watched it overfly Cuba, Eastern USA seaboard and the blue Atlantic, pass into earth-shadow on the ground (but the space station still in the sunlight), then when the tracker indicated that it was over the south tip of Ireland went outside and watched it, high in the sky, disappear into darkness.

All in about 15 minutes! Magic!

Jim

Hello all

You need one of these to load the jaws in the proper direction against the scroll.

I used a stone just a little smaller in diameter than the jaw gripping diameter

Can't remember what I used as the grinding spindle, could have been the

spindle from my Taylor Hobson engraver and a lash-up drive.

I think the original idea was from "Duplex" in ME.

Jim

Hi all

I don't usually raise Health & Safety, common sense should cover most things

However, safety shields near millers and grinders should be polycarbonate and about 6mm thick.

This is tough under impact and not inclined to fracture into shards at eye level.

Perspex is not good. Acrylic is better, but comes in several grades, I suspect the DIY stores stock will the lowest toughness stuff.

Jim

ps I built my Quorn ten years ago, ball handles and all, and am constantly amazed at its versatility.

Mark

60 degree 25 mm cutter will do all the dovetail slides in our scale of engineering

regards

Jim

Hello Mark

You need a 60 degree cutter to make dovetail slides

its all a matter of where you measure the angle from!

the ones I have are 22 mm and 25 mm

the 25 will do all the dovetails on our sort of projects

regards

Jim

Hi Neil

I can only quote Duplex:

"The forged tool has its cutting

portion shaped like a parting tool,

but the angular set enables the tool

to be mounted in a way that avoids

fouling the chuck jaws or shoulders

on the work when machining the

grooves in either a plain or a threestep

pulley."

If you try it you will see how much easier it is, with lots of side clearance for the tool.

Especially on an ML7 where the topslide cannot be fully rotated.

I have never experienced judder with this tool in spite of the overhang.

Jim

Hi Ian (Slotdriller)

All you need is one of these:

Google "grooving vee pulleys Duplex" to find an old ME article

Makes lots of swarf though!

Jim

Hi Lloyd

Put the lathe centres in the headstock spindle and tailstock, bring them together and insert a thin flat strip such as a Stanley knife blade between the points. Bring them in light contact. If the centres are in alignment the strip will remain vertical. If your tailstock really is .5mm out of alignment the strip will deflect. This test can be remarkably sensitive. The centre points must be in good condition, not bruised at all.

Jim

Hi all

Thinking outside the box ?

**LINK**

Jim

Hi JimmieS

Black & Decker Powerfile. Every home should have one.

regards

Jim (another OAP)

Hi Rick

Here is a toolbit for a boring bar, with a brazed carbide tip.

The carbide was from a scrap masonry drill, and is 1 mm thick. It is silver soldered to a 6mm diameter piece of silver steel rod. The solder was a small flake flattened from silver solder wire.

The carbide was tied on with steel wire after cleaning & fluxing. This stops it from moving as the flux is heated. The wire is removed when grinding to shape with a diamond wheel. You can just about see the solder line, surface tension pulls the carbide onto the steel stock. The assembly was allowed to cool slowly as noted by Keith (CuP) above.

I used this when line-boring sintered bronze camshaft bushes in a vintage car engine. For some reason sintered bronze "oilite" is quite abrasive and HSS bits tended to wear. I used similar bits when boring iron castings for a Quorn. This bit did not need re-sharpening during the job.

regards

Jim

Hi all

re balsa

Some years ago, British Rail Civil Engineers used large baulks of pitch pine, about 12" square by 3' long (I write in code so that only my generation understands) as packers when jacking heavy objects on track (such as derailed wagons). Of course this doesn't happen any more except on preserved railways.

Anyway, H&S was worried about fragile staff lifting heavy things, and in my testing Lab at Derby I was asked to test some blocks made of balsa. The blocks were made of end-grain laminations, the whole encased in GRP. They were very light compared to the blocks in use and easy to handle.

We found that they performed very well with loads up to about 20 tons (more code) suitably distributed, but subject to the need to apply the load on the end grain and not across it. The blocks were marked accordingly.

The idea was abandoned as... guess which way they got loaded when in use on track.

Jim

Hi Ian

re diamond wheel "truing"

Truing and cleaning are two separate issues.

First, truing ie getting the wheel to run true without "wobble". I have limited experience of one Arc Euro wheel, for use on my Quorn to shape/sharpen home-made brazed carbide-tipped boring bar tools.The wheel as received was pretty good but I decided to experiment! I reverse mounted the diamond wheel in the 3-jaw Griptru chuck (face and jaw runout checked/adjusted beforehand), and took a light cleanup skim on the back face of the aluminium body of the wheel.This was then checked for parallelism on the surface plate using a vernier height gauge. I also took a cleanup skim out of the bore. The wheel was then permanently mounted on a Chaddock-style arbor for use in the Quorn.

It appears to work ok, ie the whole circumferential diamond face gets used, and the assembly balance was good.

Second, cleaning. I have not tried this, but have read that a white aluminium oxide stick is used to refresh the diamond surface. This abrades the resin matrix and exposes the diamond particles. You stop when the alum. oxide starts to be cut away by the diamond. I recall from somewhere that the sticks are expensive to buy, but I suspect you could use an old grinding wheel (caveat experimentor!) I have also read somewhere that you can use a piece of natural limestone to clean. Maybe someone else here can confirm/deny this?

Hope this is of use.

Jim

Hi all

Copper tube in a pistol drill and valve grinding paste works well but a bit slow. The tube can be copper rod of appropriate diameter with a blind drilled hole. Don't try it on toughened glass!

Jim

Hi all

Does anyone have practical (ie hands-on) experience of the Machine-Mart-type propane turbo heaters, aka Little Devil etc., in a workshop environment. In particular, with regard to condensation and fire-hazard (discounting the obvious like petrol tanks etc) in a workshop that is basically a barn-type building and not easy to insulate, so continuous heating is too expensive.

regards

Jim

Hi all

There was a story years ago about a house built in Hollywood, designed by a noted French architect.

The French architect's drawings were in centimetres, the American builders worked in inches, the resulting house was 2.54 times too big. Unsurprisingly, being Hollywood, nobody noticed.

Jim

Hi All

Some years back I had the pleasure of working with Dave Powell, who was Harry Powell's son. Dave worked on these model locomotives with his father, mainly in interpreting the full size drawings into machining drawings for the models. Harry Powell was a boilermaker at Crewe, his son was sometime in charge of the Derby BR Research machine shop alongside the Mechanical Testing Laboratory that I was sometime in charge of.

Dave told me once that his father had been confidentially asked not to enter any more of his work into competitions in order to give the rest a chance!

Harry's work output was prodigious, including three-at-once large scale (71/4" or maybe bigger) narrow-gauge locomotives that from memory were of Vale of Rheidol prototypes.

Great memories of BR Research in Derby, sadly now mostly gone due to the benefits of railway privatisation and the overwhelming need to make a profit for the bean counters.

Jim