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Member postings for Jon Gibbs

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

Thread: homemade anvil.
27/06/2018 10:58:17

This guy's quite a good YouT presenter on blacksmithing stuff and anvils...

**LINK**

Thread: What did you do Today 2018
27/06/2018 10:37:58

Just finished making and fitting some new cast iron bushings for a pedal block of an old VeloSolex moped for a mate.

The old ones were all wallowed out and the pedals were all over the show.

In the process of getting the pedal block off he butchered the retaining bolt and so I had another one to make too.

Perspective playing tricks with the photo there, the two are the same size honestly blush

Jon

Edited By Jon Gibbs on 27/06/2018 10:39:24

Thread: Minilathe Tooling Set
20/06/2018 11:50:22

I would just buy medium and fine unless they come as a set of 3.

My experience is that they all eventually become "very fine" after a while but that might be the repeated use and "tongue-oil" lubrication I use wink

HTH

Jon

Thread: Threadcutting in the lathe - help please!
20/06/2018 09:59:49
Posted by Mick B1 on 20/06/2018 09:28:47:

I see I was lying about Eff Dia being halfway up the thread flanks - it's where the width of the thread profile is half the pitch.

I think you were right - if you extend the thread flanks from one peak to the base of a perfect trough it is half-way i.e. H/2 down or up.

Jon

20/06/2018 08:56:31

Hi John,

I'll do my best but IME you have picked the hardest thread-form to replicate first wink

[Edit: Legend added: A diagram of an ISO metric or Unified thread, showing dimensions relative to the pitch (P) and thread height (H). Note that while diferent standards, ISO and UTS share the same geometry, but not absolute dimensions. Also shown is the location rounding permissible in internal (dark grey, top) and external (light grey, bottom) threads. Key P: Pitch H: Thread height Dmaj: Major diameter Dmin: Minor diameter Dp: Effective pitch diameter Do not scale from this drawing.]

The best economical way to compare threads is using measuring wires (Available from Arc Euro Trade) and a micrometer. With wires you are effectively measuring part way down the flanks of the thread and so you can tell if the profiles are the same between a reference and your attempt - or indeed when using conversion tables you compare to the given effective diameter which is the diameter half way down the flanks. See the picture.

Whitworth has a rounded crest and root which can be difficult without a chaser or a die of some form. So, it is not uncommon to truncate the crests (at a smaller nominal diameter) effectively to a flat as would be the case in the metric and US 60 degree threads.

If I could recommend a new book to you. Try Martin Cleeve's "Screwcutting in the lathe". It's cheap but very good on all things related to threadcutting.

I hope this helps. Happy screwcutting! 

Jon

Edited By Jon Gibbs on 20/06/2018 08:59:19

Thread: Minilathe Tooling Set
19/06/2018 15:24:19

Paul,

Ok, thanks for the clarification...and yes, I did read your posts - more than once.

Jon

19/06/2018 14:28:01
Posted by Jon Gibbs on 19/06/2018 08:48:37:

Hi Ron,

I hate to pour cold water on your morning but I'd put them in a drawer and forget about them for while unless you have a grinder with a green or diamond wheel capable of touching up the edges of the tools and get them sharp enough to cut - and to restore the edges when they chip. The set you have will cut initially but could also be a recipe for frustration in the short term without means to redress them.

...

If you have a conventional grinder with a grey or white wheel then I'd buy a HSS right hand knife tool, a boring tool and a parting tool of this pattern in the right size...

...

Paul,

Before casting aspersions and labeling us all bad workmen did you read the posts?

Jon

Edited By Jon Gibbs on 19/06/2018 14:36:15

19/06/2018 11:13:43

Hi Dave,

+1 for the comments but I think you have your left and right swapped.

Jon

Thread: Meteor detecting
19/06/2018 10:45:05

It sounds a fun thing to try.

I did some research into meteor burst communications a while back - trying to maximize the data throughput - because as the ionization trail dies away the reflectivity, and hence the link capacity, diminishes.

The problem with meteors as a means of communication is that they are not regular throughout the day. The earth mops up lots more meteors at 6am local time than it does at 6pm where only those travelling faster than the earth can graze the ionosphere.

Jon

Thread: Help needed making Harold Hall's Grinding Rest
19/06/2018 09:08:23

Hi Joe,

I peck-drilled mine through with a long cheap 5mm drill and then expanded it to 5.2 from each end. That way I didn't need to buy a long 5.2mm drill. The key is spotting drilling first and frequent swarf removal as Paul and David have said.

It is only a clearance hole for the 5mm leadscrew and so if you make a mistake you could always drill it over-size, fit plugs at each end and drill two 5.2 holes through the plugs in the right places to result in a straight bore at the ends. No one will ever know then and it'll work just fine.

HTH

Jon

Thread: Minilathe Tooling Set
19/06/2018 08:48:37

Hi Ron,

I hate to pour cold water on your morning but I'd put them in a drawer and forget about them for while unless you have a grinder with a green or diamond wheel capable of touching up the edges of the tools and get them sharp enough to cut - and to restore the edges when they chip. The set you have will cut initially but could also be a recipe for frustration in the short term without means to redress them. I bought a set like yours when I started and it was a waste of money for me - although now I have a diamond wheel I use the left and right knife tools occasionally for cutting through rusty and mucky stuff and the scale on cast iron.

If you have a conventional grinder with a grey or white wheel then I'd buy a HSS right hand knife tool, a boring tool and a parting tool of this pattern in the right size...

...that should get you turning with something you can sharpen and do most of the things you'll want from an initial set of tools until you get threading, at which point you can buy the internal and external threading tools. Chronos sell individual tools and ArcEuro sell sets.

The alternative is to buy some HSS blanks and grind your own tool forms but these tools are a quick and cost effective way to get turning quickly and easily FME. I still use my tools of this form as a complement to hand ground and insert tipped tooling. Many people sware by the tangential tool holders but they are expensive unless you can make your own and they are just right-hand or left hand tools really.

Good luck and have fun - I hope this helps

Jon

 

Edited By Jon Gibbs on 19/06/2018 08:57:55

Thread: Missing post
12/06/2018 11:02:19

Hi Mick,

While I stick to NDIY's idea of only spending what I don't mind losing, my experience of that supplier has been pretty good TBH. I tend to prefer to buy direct from the Chinese warehouse to expand the range available and also save a few quid - although I do stick to stuff below £15 to avoid being stung by VAT and charges through customs. The stuff has all come eventually and postage is free which is incredible.

...but I've had some great deals on tooling (TC inserts, boring bars and holders) and recently some diamond wheels. All have been ok for me and have been worth the punt IMHO - I've had no duds and even gone back multiple times to equip myself with several CCMT boring bars of different lengths to fit my boring head.

HTH

Jon

Thread: What did you do Today 2018
12/06/2018 10:42:14

You might be right Dave. Another explanation is that they are simply not quite ready yet... **LINK**

I am perplexed by the Turkey servicing too although on paper they are full long-standing NATO allies and it might be a useful lever to get some sort of concession on human rights eventually.

...but with a certain person acting the way he is at the moment, we, and the EU, might find ourselves embargoed by the US and our F35's sold to Putin and Kim Jong Un instead!

Jon

12/06/2018 09:01:59

Talking of strange decisions from MoD, I'd be interested why the first batch of single seat F35B's was flown 3000 miles from the US to UK with all of the discomfort and hazard for lone pilots, including in-air refuelling etc, when HMS Queen Elizabeth could have carried them across the Atlantic? She is on sea-trials at the moment, is designed to carry F-35's eventually anyway and would've been something useful she could have done.

Jon

Thread: Myford ml7
08/06/2018 10:59:14
Posted by KWIL on 08/06/2018 10:24:33:

ML:7 were never yellow, only Myford woodworking machines used yellow. Myford Grey is the correct colour for a ML7.

Hmmm - I don't want to sound like a Golgafrinchan and a pedant....

You're right about the main colour but the gap between the ways on my old ML7 which is original (because I can't and won't be ar$ed to paint it) and the same yellow as the woodwork machines. Is mine the only one? - I doubt it.

Jon

08/06/2018 09:28:05

It's also worth checking out...

**LINK** and

**LINK**

HTH

Jon

Thread: Plastic for machining threads in particular
07/06/2018 15:01:42

Nige,

Once you've tried a few bits of plastic though I don't think there's any substitute for cutting steel if that's your intended end-product. Plastic is too forgiving and especially if you've got an old or worn machine like mine the thread depthing, springing and crest burs will be entirely different with steel than plastic.

Moving on to some leaded EN1A would be my suggested path PDQ.

Also, although you can get by without for the very basic basics, buy yourself some thread measuring wires and Martin Cleeve's book "Screwcutting in the Lathe". You can buy both for ~£15 total from Arc.

HTH

Jon

Thread: Vancouver steam clock
01/06/2018 15:17:13

I've not seen the one in Vancouver but I've seen the steam clock in San Francisco which looks pretty similar...

...I think I must be going bonkers. I've looked and can't find any pictures now. Perhaps it was Vancouver after all embarrassed

 

Edited By Jon Gibbs on 01/06/2018 15:32:10

Thread: Q: Bandsaw Speeds?
31/05/2018 13:53:11

Posted by SillyOldDuffer on 31/05/2018 12:26:10:

Might be worth giving yours a critical inspection, quite likely it would benefit from a little fettling.

Dave

Thanks for the tip Dave, I might give it the once-over then and try again with a bi-metal blade.

Jon

31/05/2018 11:11:41

Admittedly I have the smaller saw than yours but have had all sorts of trouble with bimetal blades - they seem to be much stiffer and stress the weld in the tight twists - eventually breaking before the teeth are close to being worn.

The good news is though that flexible HCS blades (such as those from tuffsaws **LINK**) will cut just fine - even cutting silver steel and stainless without too much trouble. My bandsaw stays set on the slowest speed as it's too much of a fiddle to change and that way my blade lasts longest and it doesn't take too long.

HTH

Jon

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