Member postings for Andrew Tinsley

I have a boring. bar which came with some tooling. It has the following on it

S-SR-SCLCR09 . Not easy to make out the lettering, The first S may be incorrect and the L is very indistinct. The insert has a diamond shape and has sides of 9mm and an 80 degree angle. It is retained by a T15 countersunk Torx screw.

I have looked up the meaning of some of the symbols and have concluded that the insert is an SCLCR09 type, although I am not certain. Can anyone tell me the correct designation for the inserts?

I don't wish to make an expensive mistake when ordering new inserts!!

Regards,

Andrew.

Why do you say that the model engineering world is still imperial? It all depends on the individual's preference, How many model engineers do you know who prefer to use imperial measure and how many use metric?

Sure, the history of model engineering is imperial for obvious reasons. You should not take this as a justification for your sweeping statement.

Andrew.

I use any standards that are called for, be they metric, imperial or even older standards. It causes me no problem. The only downside is that you need extra kit. But again that isn't a problem for me as I repair old stuff that calls for just about any of the thread standards you could think of. So having lots of different tooling is a benefit.

Andrew.

So that's a new way of building a car? Sounds like more typical Musk b******* to me.

Andrew

Moderators Edit see comment below.

Edited By JasonB on 03/03/2023 14:47:15

Much better than a smart phone, which I don't have!

Andrew.

Zoro can beat that with ease. A couple of small items in a box that my cat can curl up into. Apart from the small items, the rest was filled with very large plastic inflated sausages. The cat doesn't complain!

Andrew.

Zoro can beat that with ease. A couple of small items in a box that my cat can curl up into. Apart from the small items, the rest was filled with very large plastic inflated sausages. The cat doesn't complain!

Andrew.

I would guess that it was made by Porta. They are (were?) a very respected manufacturer of drill chucks. I have one and it is every bit as good as my older Jacob's chucks. They were still in business up to a couple of years ago. But who knows if they still are.

Andrew.

Bottle and Jar threads are listed in an old book I have , it simply lists about every thread you could think of!

Andrew.

I paid about £50 for the chuck, so somewhere in between the £20 and £80. So which quality did I get!!!!!!

Andrew.

I recently purchased a No 34 Jacobs chuck from large commercial seller. I was somewhat disappointed by the chuck, very poorly finished, compared to some of my old Jacobs chucks. Run out was good, but I was so disappointed that I returned the chuck for a refund.

I can't imagine that the respected seller was pushing fakes. So have Jacobs started sourcing from the Far East and I just got a bad one?

Andrew.

Hello Bernard,

The tappet adjusters on the Petter are 1/4" UNF, checked with measuring the diameter of the adjuster and a thread gauge.

For the A series tappet, I inadvertently typed 7/16". It should be 5/16" UNF !!!!!! Thanks for correction. The adjusting nut is 7/16" across flats and the very later A series had 1/2" across the flats, adjusting nut.

Thanks,

Andrew.

Edited By Andrew Tinsley on 20/02/2023 21:30:33

Well you live and learn! I have had just about every A series engine except for the 803! These all had 7/16" UNF tappet adjusters!

Thanks for that Bernard, I should have more success looking for those..

Andrew.

Hello Robert,

Good thinking, but A series tappet adjusters are 7/16" UNF. As I found out long ago!

Thanks,

Andrew.

Hello,

Thanks for the idea, The O/D of the thread is 1/4" UNF, The hemisphere on the tappet adjuster is actually the core diameter so a good bit smaller than !/4". By the time the thread has been turned off and a hole drilled in the ball bearing, you are talking of a very small spigot diameter. I am not sure I like the idea for such a small spigot I suppose JB weld may be OK as an adhesive, but the ends of tappet adjusters get a good hammering. I would be afraid that the small spigot would break and that could cause a fair bit of damage

Regards,

Andrew..

Hopper

Unfortunately the tappet adjusters are no longer available to buy, hence making them is the only solution, So you give the home made ones a couple of hours before they ruin the push rods? Goodness knows if the grub screws can be hardened, I wouldn't know where to start looking for AINSI standards.

Looks as though it might be better to go Chris Evans route and make them out of silver steel and harden them? I have never had much luck threading small diameter silver steel, I always finish up with a very ragged thread. Doesn't matter if I use a die or screw cut, the silver steel is good quality stuff (Coventry Grinders).

Andrew.

I thought of using grub screws (with a hex hole) as most of the work has been done. The ones I have ordered are quoted as being high tensile and meeting AINSI B18.3 standard. Anyone know if that spec is suitable for my intended use?

Like Chris, the tappet adjusters will get a very easy life in my Petter driven alternator. Used for power cuts only, apart from annoying the neighbours when test running and annoying them even more when there is a power cut.

Andrew.

Edited By Andrew Tinsley on 19/02/2023 22:34:17

Probably showing my ignorance, but isn't a ball ended end mill, one that has a ball or hemisphere on the end? I want a ball or hemisphere on the tappet adjuster, not on the cutting tool, or have I totally misunderstood your suggestion?

Regards,

Andrew.

Now why didn't I think of that. Thanks Bill and Noel. I have this vision of form tools as being for much larger jobs.

Thanks again,

Andrew.

The tappet adjusters (basically a threaded rod and adjusting nut) need replacing.

I have sourced some long, high tensile, 1/4" UNF grub screws and grade 5 nuts. The grub screws have a hex slot rather than a screwdriver slot which is easier when it comes to adjustment.

It is the other end of the grub screw that presents a small problem. I need to make them hemispherical to fit into the top of the push rod.. I don't have a ball turning device and apart from the use of warding files, I don't have a good idea of how to do the job!

I am sure I am missing a trick here or overthinking the solution, so any suggestions? Otherwise it will be files and Mk 1 eyeball.

Andrew.