Member postings for Neil Wyatt

Hi Allan,

You're looking at adjustable reamers, if you use those you'll get an accurate hole, but will probably not get it dead on size. You want either machine reamers (that only cut on the end) or hand reamers (that have a tapered lead). I managed with just their 1/16" to 1/2" 10-piece hand reamer set (£35 from Tracy) for many years. I now have some machine reamers (1Mt and 2MT in larger sizes, which suit different jobs, and I find they can take a deeper cut too.

You could ream the bearings in line in the same way as boring, but using a hand reamer in the chuck. If you run out of travel, leave the reamer in place in the work, remove from the lathe and wind it through the rest of the way using a diestock.

There are dozens of ways of skinning this cat.

One engine I'm working on is 'house built', so like the original at least one of the bearings will have to be mounted on an adjustable base to be aligned correctly on final erection. Another is designed so the bearings will be OK as long as their centres are exactly the same height, and side to side alignment is by a pair of wedges on either side of each bearing block.

Neil

Not wishing to be a smartass, but in my original post I did put "my original idea of copying Alec Issigonis and having a lump of rubber under each suspension arm" ;'

I didn't realise you could get Bellville washers that small, but somehow I think managing a stack of 40 is going to be lot more critical than a spring poking out of a hole...

> Stainless is completely sun- and weatherproof, and can be polished, of course

In that case, I'd better use rubber as it fits better with the RABA-WIWIT approach.

Neil

Thanks Ian,

I have just had a go at the lee Springs search. The best I can get is about 14 N/mm, it seems the springs I have at 1.45mm diameter wire are unusual for such a small external diameter. I suspect they are meant for something like detent or ratchet springs that need to have a lot of force but little movement.

Neil

Sorry, I left out the critical bit... they need to be roughly 25mm long as the travel needs to be about 6-8mm. I have got screw adjusters to balance the springs (I will probably need to balance fore and aft once I have got my seating position sorted!)

At the moment the 6mm springs are in 1/4" holes with M5 screws poking into the ends for adjustment. I can bore out to 8.5mm (would rather limit it to 7.5) for a bigger spring, and add an end cap to the adjusters. The idea is to adjust the amount of spring projecting to be about 10mm, or 5mm under a static load of about 250 N per spring. This would give 5mm more travel before the arm bottoms out, hopefully stopping the spring from completely closing up.

<PAuse for experiment>

I've just done some experiments with 25x10x10mm lumps of rubber cut from a lorry mudflap. Sandwiched between the spring arms and the chassis they work really well. I can move them towards and away from the fulcrum to get different rates.

Better still, I've discovered that,by attaching a length of rubber in line with the suspension arm, as the rubber compresses the size of the contact patch increases, so I get an increasing spring rate with load, ideal for suspension purposes.

I thjnk I've made my decision!

At the very least, I should provide some entertainment for onlookers as I bounce down the track.

Neil

Question first:

Can anyone suggest a spring supplier who could supply 7mm springs with a rate of over 50 N/mm and ideally with a minimum order value below £18+vat & p&p?

Explanation:

I am looking for some very small, strong springs. I have some that are 6mm diameter from 16-gauge wire and an inch long. At least they were an inch long, they are now about 0.7 inches long, after being compressed with a load of about 50 kilos. This was nowhere near enough to close up the coils, but obviously overstrained them. The springs that failed had a measured rate of about 0.29mm per 2 kilos, which is about 60 N/mm (an online calculator suggested it should be 56 N/mm).

To my mind a larger diameter spring with a rate around 50-60 N/mm should be able to take these loads and recover fully.

I can substitute springs with an external diameter of up to 8mm, but I'd prefer 7mm. The highest rates I found 'off the shelf' are 12.4 n/mm for 7mm and 16 n/mm for 8mm.

These springs are for my driving car, and the other options I have are doubling up the springs, or my original idea of copying Alec Issigonis and having a lump of rubber under each suspension arm.

> B and Q sell 12mm WBP plywood and the larger stores can cut it to size for you.

I wanted a 2" strip cut off the edge of a 24" ply board for a benchtop.

"Sorry we can't cut smaller than 9" for H&S reasons."

"But it's the big bit I need making smaller!"

"That's OK then."

Naturally I took away both bits. The offcut has made a nice trough at the back for hiding cables etc. in. I just need to make a lid for it.

Neil

I see there is now a working link from the picture on the homepage to the order form HERE

Neil

> But is there one available for Zinc ?

Indeed there are pens for a whole raft of metals, my understanding is that if you can electroplate it, you can use a pen to do it. I think they are probably the most effective route for small parts, especially if you are worried about losing detail.

**LINK**

Neil

I know a chap who restores banjos. He does all his bright nickel plating using a 'plating pen' with excellent results.

Neil

Hi Geoff,

Solitary bees and bumble bee nests only last one season. If they are reused it is just because they happen to be in a good place.

Some species of bumble bee like to use old mouse nests! Anotehr way to encourage them is to 'plant' old clay flowerpots upside down so there's a space inside about as big as a tennis ball with good access through the hole in the bottom.

This might be useful **LINK**

Neil

If you want to practice casting before making your own moulds, Hobby's sell a range of synthetic moulds for 54mm figures. They claim a mould life of 200 pours, but I imagine there are many variables.

Neil

I've often seen a few tablespoons i in a gallon recommended, which seems very weak to me, given how much is in the average kettle descaler packet, but apparently this works well and if you make it stronger it can go a bit funny..

Neil

Finally made some more progress on my driving truck. Not looking for medals, just a functional design. I'm going for suspension arms with very small but powerful springs to give about 3/16" travel. The ones I got will compress 2.5mm with a load of 50lbs, which is a quarter of me. The M3 screws will give spring preload adjustment. The disk brake mechanism next, and, of course, some pivots for the suspension arms, which if designed right will stop teh springs from being able to fall out.

I'm banking on the travel not being enough to lock the bearings =:-0

Buffer blocks will be wood and large enough to be compatible with 3 1/2" and 5" buffers.

For ground level a simple wooden box will go between the seat and the chassis.

If it doesn't work, I can always use it as a skateboard

Neil

Part 4 appeared in issue 141. There were 8 parts in all. I don't know why only 1,2,3 and 5 were put up on the site, as this ahppened about five years ago.

Part 6 was in issue 146 and part 7 was in issue 147. Part 8 was in issue 158 (there was a big gap when David took over as editor of ME).

I'm afraid I don't have the original copy it isn't going to be practical to put them all up as articles, due to the time required to extract the text and pictures. They can all be found in the archives.

Neil

The only unnecessary padding around MEW these days is just north of my waistband

Neil

Thanks Michael,

His was rather more 'finished' than that but it's nice to know how it's done.

I recall his as being much slenderer than THIS one at Cosford.

Neil

Sorry Ray,

That's the second time I've done that with my email. I've re-edited the links in my message and your quote.

The problem is that there are three ways of digitally viewing the magazine.

The first is standard 'pocketmags' online reader.

Second is the non-downloadable online archive explained here:

**LINK**

Finally there is the 'pocketmags' offline reader package which does allow you to permanently download issues, explained here:

**LINK**

Unfortunately, the system tends to get people into the online archive (via the magazines link) and the offline package is not so easy to find.

We have had some issues with 10-digit numbers and I'm still not sure how they are best sorted. I will try and find out for you on Monday.

I'm sorry about the byzantine complexity, hopefully these links will help.

Neil

These pliers are so worn as to be virtually useless. But they belonged to my maternal grandfather who died when I was too young to remember him. He was a coppersmith in the RAF. My Nan also used to have a Spitfire he had lost-wax cast from a old penny - I think making these was a bit of a standard test piece as I have heard of others. I know he served in Egypt, among other places as she had pictures he took including the pyramids and one of either Hengist or Horsa, the big biplane airliner.

Neil

Sorry Derek, that was ME, indeed I think several such 'running board' pumps have appeared in ME over the years in varying levels of detail. You can, of course, lobby Diane to see if she can republish one!

Neil

Or chuck the magnet in the garden and let the filings rust, after which they can be brushed off.

Neil

Edited By Neil Wyatt on 16/05/2014 21:45:29