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Member postings for Roderick Jenkins

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

Thread: Parting problem - Morse taper
17/08/2019 13:44:04

A couple of points if I may:

I think the Sherline lathe headstock is the same as on my Sherline /Denford mill and this will take a full No.1 Morse taper. If using the full length 1MT then you will need a smaller diameter drawbar. Mine is 1/4" and holds an ER11 1MT collet chuck nice and firmly. The drawbar need only be a length of studding with a nut.

My experience of blank end arbors is that they are harder than mild steel but not excessively so. I do not think the shank will be any different from the head and they are sold so that you can modify them to your own requirements.

Hope this helps,

Rod

Thread: Velocette
16/08/2019 23:27:08

Graham,

That's a good looking gear and, frankly, I wonder if for a gear with that many teeth and such a shallow angle one would really be able to tell the difference between one that has been cut straight across at an angle and one that has been cut in the correct helical fashion.

Rod

Thread: Heartbroken!
16/08/2019 18:21:38

With respect, you wouldn't need to heat the fabrication up to red heat in order to soften a carbon steel tap. Tools are usually considered to be spoiled if they get to blue, which is about 300C. You've another 300C to play with before the silver solder starts to soften - and that's ignoring any liquation effect which will raise the solder melting temperature even further.

Cheers,

Rod

Thread: Velocette
16/08/2019 17:01:47

Whoa... If we really are talking about helical gears then that's a whole different problem.. Helical gears can be cut using form cutters but it takes a bit of fiddling around to produce the necessary lead on the blank.

Rod

16/08/2019 15:55:30

Graham,

Sets of gear cutters only produce the true tooth profile for the number of teeth at the bottom end of the range stamped on the cutter but the system works fine. Bearing this in mind I can see no problem in your original plan, I'm sure the gear will mesh adequately. Since Jason is showing off, here's a pair of 0.8 MOD gears I cut for my Farm Boy last week.

g9a.jpg

I bought my set of cutters from CTC.

Cheers,

Rod

Thread: Boiler testers and material verification
07/08/2019 10:59:12

Can I put forward this argument, based on no specialist knowledge whatsoever:

The boiler testing code in the UK has been put together between the insurers and model clubs. The code does not guarantee that the boiler is intrinsically safe but that it provides a reasonable risk that the insurer is prepared to underwrite. History has shown that the fairly loose requirements for silver soldered copper boilers have provided a reasonable risk for the insurers. If an exploding boiler is not insured then I suspect that all the risk falls on the operator/owner - regardless of any inspection certificate.

Discuss...

Rod

Edited By Roderick Jenkins on 07/08/2019 11:26:00

Thread: New Mill - Starter Tooling
28/07/2019 18:03:32
Posted by Ron Laden on 28/07/2019 14:49:04:

Would anyone happen to know the rubber thickness of a bicycle innertube...

I've got a collection of old inner tubes waiting to come in useful. Thicknesses are between .75 and 1mm.

HTH,

Rod

Thread: change wheels
24/07/2019 13:32:33

RDG tools have them as do Home and Workshop Machinery.

HTH,

Rod

Thread: Mystery machine..........
22/07/2019 21:07:44

It looks similar to the "Duplex" design in Ian Bradley's "The Amateurs Workshop"

duplex hacksaw.jpg

Rod

Thread: Surplus subjects learnt at school.
19/07/2019 18:48:12

Until the the late sixties you had to have Latin 'o' level if you wanted to go to Oxford or Cambridge. It would have been a pity to constrain your choice if you didn't have it wink

Rod

Thread: Crystal Ball Gazing
19/07/2019 09:50:18

Quote from Wikipaedia:

"Proxy measurements can be used to reconstruct the temperature record before the historical period. Quantities such as tree ring widths, coral growth, isotope variations in ice cores, ocean and lake sediments, cave deposits, fossils, ice cores, borehole temperatures, and glacier length records are correlated with climatic fluctuations. From these, proxy temperature reconstructions of the last 2000 years have been performed for the northern hemisphere, and over shorter time scales for the southern hemisphere and tropics."

Rod

Edit -  beaten by 1s!

Edited By Roderick Jenkins on 19/07/2019 09:52:02

Thread: Gibraltar Toolpost
19/07/2019 00:00:38
Posted by Mark Rand on 18/07/2019 22:28:24:

The residents of the rock, And the late Tom Walshaw might prefer it if folks referred to the Gibraltar tool post by its correct name. cheeky

Edited By Mark Rand on 18/07/2019 22:28:36

blush

Thread: TTFN
18/07/2019 19:28:56

Well, that's a shame. Please don't be a stranger for too long.

Rod

Thread: Gibraltar Toolpost
17/07/2019 12:07:08

The Gibralter Toolpost is also detailed in Tubal Cain's book "Simple Workshop Devices"

Rod

Thread: A few newbie questions, sorry
16/07/2019 12:18:14

Question 2,

I think best practise is to have the faces with the bolt holes mating. On 4 jaw (independent) chucks the bolt holes are towards the middle which means that a smaller backplate than the chuck diameter can be used. With the 3 jaw chuck the bolt holes have to be around the periphery to avoid the scroll. The caveat is that this applies to screw on chucks.

HTH,

Rod

Thread: What started your interest?
16/07/2019 11:54:47

I started making musical instruments as a hobby in my twenties. I then thought I would get a lathe to make some musical instrument making tools. It was just a downward spiral from then on...

Rod

Thread: Any other bowmakers on here?
15/07/2019 22:11:30

Mike,

I drilled the hole for the screw on my bows by poking the stick down the headstock and rotating it held in a self-centering 4 jaw chuck. However, my bows didn't have a camber. At what stage do you bend your sticks?

Mark,

I see that Mimusops seems to more generally known by the name of Manikara these days. It was definitely sold to me as Beefwood and I see that one of the common names for the Manikara Huberi is the Cow Tree so it would not seem unreasonable that it produces Beefwood - such is the timber trade. You can only really go by the botanical name if you want to accurately know what you are buying - even if they do keep changing those angry

Cheers,

Rod

15/07/2019 15:56:33

Hi Mike,

I've been away from the internet in Mull for the last week or so and have come late to the discussion. I've made a few "historical " bows in the past to go with the Viols and Baroque style violins and violas that I had a go at making. These bows were rather less sophisticated than the modern Tourte bow with a simpler frog and a positive camber caused by the hair tension which, in the case of the viol bows, is adjusted while playing using the fingers in an underhand grip. Although Snakewood seemed to be the go to wood for earlier bows I could never justify the expense - this bow was made from Partridgewood.

bow head 2.jpg

I used to buy my tonewood from Maurice Bouette at the Newark school. I never met him but used to receive charming hand written letters discussing my requirements. Some years (decades really!) ago I was buying some supplies at Timberline. They reckoned that many modern bows were made from Beefwood (Mimusops Huberi) and sold me two baulks of the stuff for a very reasonable price compared with Pernambuco. It's a bit denser than Pernambuco and a bit darker but produces a nice shiny finish with wet'n'dry.

Nice to have you aboard,

Rod

Thread: Cast iron - 160mm dia
05/07/2019 17:41:23

Comparing the material properties may be interesting but I suspect that the real reason is that c.i. can be easily cast with a nice boss on the back.

Rod

Thread: Easy Button Die Storage Solution
20/06/2019 10:30:45

Worked for me for the last 20 years

dies

Rod

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