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Member postings for richardandtracy

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

Thread: What Did You Do Today (2017)
26/05/2017 20:42:16

I have no stuff. But my workshop is bulging at the seams.

My wife has lots of stuff, but claims (wrongly) she has none. And her workshop is bulging at the seams.

Just a matter of perspective.

Regards

Richard.

Thread: The domestication of Laser Cutters
26/05/2017 11:55:37

At 38x38mm work area, it is a bit small... Shame all these things seem to work on a raster type control.

Also says it can't engrave acrylic [or metal]. Bit limited, but may be worth a play.

Regards,

Richard.

Thread: New Zealand space launch
26/05/2017 10:29:28

They say they want to do polar orbits with spacecraft launched with this rocket. The only real factor in determining where to launch for polar orbits is a good fetch of water to the east. As the rocket goes up, it naturally tends to drift off to the east, so it's better if no-one is there if something goes wrong, and having a big bit of water in the way tends to ensure that.

Regards,

Richard.

Thread: The domestication of Laser Cutters
26/05/2017 09:55:12

The 'Mr Beam' one looks like a 'marketing slicked over' version of this:

**LINK**

It would leave you £1250 to make the protective box with and buy a hacksaw to shorten the travel.

I do think the Mr Beam stuff is going in absolutely the wrong direction. It is making something that is inherently useful & practical into something 'Cool, fluffy & ultimately useless'. A must have toy for the creative 'illiterati' to decorate their high tech, white gadget filled iHome. Not something that will be used, because it'll fill that white, sterile, iHome with horrible smoke and involve thoughts of practicality, and how to make things.

You may have gathered from my comments, I am far from enamoured with marketing makeovers or the target of such makeovers.

Regards,

Richard.

Thread: New Zealand space launch
25/05/2017 15:51:51

Don't think NZ plan on fitting a nuke to the end of their fireworks, though.

Regards,

Richard

25/05/2017 12:31:58

Thought the official 'boundary' was 100km (62 miles).

However, if it's a test flight, seems reasonable that they don't want anyone to watch. If the pre-production variant goes bang it'll scare off customers even when the cause can be cured before the production launches.

Regards,

Richard.

Thread: DIY hearth
25/05/2017 08:36:02

Cement does loose its strength over 600C, and melts around 1000-1100C. I agree.

The question is whether it'll last long enough at brazing hearth temperatures to be useful for more than one job. Having had a concrete furnace last a bit (and in a couple of areas at the top, the refractory has melted due to the ferocity of the fire I got from pallet timber) I think that the experience could be carried across usefully and applied to something else that is also unlikely to be subject to frequent & sustained heats. Don't want to rule out something that could be useful because the 'best' option is much better, when 'adequate' would work well enough to last a few years.

Regards,

Richard.

24/05/2017 23:31:43

I've not created a hearth, but an aluminium melting furnace. For that I used cement, sand & gravel. Nothing fancy. It has lasted 20 firings to yellow/white with some spalling. If you are happy to do occasional re-plastering, then cement based refractory should be OK for a brazing hearth. Possibly not up to being a proper hearth for a forge, but good for a brazing hearth.

If you've got the stuff, it would be worth trying before paying for anything extra.

Regards

Richard.

Thread: What Did You Do Today (2017)
24/05/2017 13:29:57
Posted by Muzzer on 24/05/2017 11:40:11:

As you know, skips are measured in "yards". But that's cubic yards, not length. Don't think I've ever seen one in cubic meters (or litres?).

Merry

That's because there are more cubic yards in a volume than cubic metres, so the skip sounds bigger. It's like how hot weather is always in Fahrenheit and cold is always in Celsius. It makes hot weather seem hotter because the numbers are bigger & cold weather seems colder because the numbers are smaller ( this is in the UK when it never gets below -40C/F).

Regards,

Richard

24/05/2017 11:32:57
Posted by Muzzer on 24/05/2017 11:05:25:

Not convinced the guy has listed correctly otherwise I'd be tempted at the price. "£0.99 buy it now"!!

cheap cnc.jpg

Murray

Bit heavy to move, else I'd have been tempted too.

Regards,

Richard

Thread: Workshop tips from long ago
24/05/2017 08:57:27

Gems of wisdom from the past. How about this link: **LINK**

It's every book published by the Industrial Press (of Machinery's Handbook fame) that is currently up on the Internet Archive. Most of the books are from 1900-1920, but information like that does not date. Sample titles:

  • Lathe Bed Design
  • Screw Cutting
  • Spinning
  • Milling fixtures
  • Patternmaking
  • Hobs and Gear Hobbing
  • Screw Thread Cutting

Hang on, why are you still reading this & not diverted by the books in the link?

One of the best online resources you are likely to find.

Regards,

Richard.

Thread: Knowledge
24/05/2017 08:47:42

In many ways you can get the basic knowledge from books, so when confronted with a machine you know what the bits are, how to operate it & roughly what to do.

This reprinted book is a really good starting point: **LINK**

Then, the Gingery 'Build your own metalworking workshop from scrap' series cannot be surpassed. You don't have to do any of it, but reading through the series will show you every technique you are likely to need and a few more. It will also show you the conditions where precision is necessary and where it is not (a concept a number of model engineers find hard to cope with - knowing what is 'good enough for the job' will save you huge amounts of time over the years). The series is here: **LINK**

The Gingery series, starting with a furnace, going onto making a lathe, shaper, milling machine & drill press is really a walk through the industrial revolution, teaching & implementing everything that was is currently useful to come from it. Yep, I am a fan, even though I've never built any of the machines shown. With that grounding, you will then know enough to have an idea of what else you need to know, and what questions you need to ask to get that information - a vitally important skill.

All the best,

Richard.

Thread: Acquiring a wedge type quick change toolpost
24/05/2017 08:18:41

The trouble with the cheap ones on the bay is that the post is aluminium. In time you'll get problems with wear. The steel ones don't seem to be much cheaper than Arceurotrade & as they come from the US, it's highly likely you'll get stung for import duty, making it more expensive.

I've never had anything get through from the US without having to pay duty, and have never had to pay it from China. Just remind me, which is our NATO ally?

Regards,

Richard.

Thread: The diesel controversy
23/05/2017 08:50:15
Posted by martin perman on 21/05/2017 19:30:16:

You must also inform the DVLA for change of use from van to camper.

Martin P

I didn't need to on my Sprinter. The insurer did that automatically for me without my knowledge as a result of the 'home conversion insurance' we took out on it. I was keeping the van as a 'van' because we use it for everything including moving plasterboard, mopeds, as a bus for kids & friends etc. as well as a low spec day van/motorhome. It had an unexpected beneficial side effect, though, recent changes in MOT rules have introduced a 3 tonne GVW limit for many MOT stations. However as our 3.5 tonne GVW Sprinter is a 'motorhome', it's exempt from the way the rules were worded & we can continue using our old MOT station even though their GVW limit is now 3 tonnes not the 3.5 tonnes the approval used to give. Every year for the last 4 years the Department of Transport has sent them a letter saying this loophole will be closed soon, but they haven't done so yet.

Unfortunately that van, now nearly 19 years old, is rather badly affected by rust & will be sold by Saturday lunchtime (I hope... if anyone bids for her...). We'll miss her, had her 16 years and spent many holidays in her from the time the kids were just old enough to go camping and could be trusted in a tent overnight (well, you don't want the kids in the van with you, do you?).

Regards,

Richard.

Thread: Stainless steel hexagon bar in whitworth head sizes
23/05/2017 08:22:06
Posted by thaiguzzi on 23/05/2017 03:39:22:

...Today you can buy ALUMINIUM wheel spindles for competition off road motorcycles. I'll think about that one, may give it a try...

No real reason why not: Something like 7075-T6 is stronger than many steels.

I was involved in stressing a runway beam setup in a box once & had to investigate making the steel beam a lot lighter. On looking at sensible proportion aluminium extrusion sections & 6082-T6 alloy I came to the conclusion that for the same reserve on ultimate strength, an aluminium one would weigh 40% that of the steel one, and for the same stiffness, it would be 50% the weight, though the section was 40% deeper. After lots of discussions, our customer was the one who lost their bottle & requested a steel runway beam, so it never got built & the weight saving had to be fought for elsewhere.

Regards,

Richard.

22/05/2017 14:31:11

My experience of stainless bolts is not quite the same as that of JohnChapman, but similar.

Stainless bolts can gall, and that is a real PITA. Ways to avoid it are to use different stainless grades together (303/304 bolt, 316 nut) and/or to use something like 'Duralac' which acts as a lubricant to stop galling & prevent corrosion. The company I work for uses around 20,000 A2 stainless nuts & bolts a week. Failures due to galling occur once or twice a year with those precautions. Blind holes should always be gummed up with Loctite/duralac because stainless steel is only stainless when in the presence of air - the chromium oxide is in a dynamic equilibrium with the oxygen in the surroundings, and if there is no oxygen in the local area, the oxygen is lost from the chromium oxide, and not replaced, leading to a thinner/less complete oxide layer, so corrosion is able to start. If in a blind hole, it can get wet & then there is little air, so corrosion accelerates. To stop it in a blind hole, you need the duralac/Loctite to exclude water in the same way as for a standard steel bolt.

As for strength, agreed. General A2/A4 bolts are grade 70, ie 12% weaker than a grade 8.8 bolt, and they yield at 2/3 the load. Cap head bolts are nearly twice as strong. If you are machining 303 stainless, you won't be certain of the work hardening level (unless stated on a certificate when purchased) & need to assume it's annealed. In the annealed state, they won't be much stronger than normal DIY store studding. Not a good thing!

Regards,

Richard

Thread: London Airport to be controlled from 80 miles distance
19/05/2017 09:43:38

When you can have people killed remotely by drone, doesn't it even up the scales a little to have other people kept alive remotely?

I do agree, though, it adds complexity without adding anything to the safety that couldn't be done better at the airport with the same investment in cameras/equipment. Also has the problem that it will fail dangerous, while a control tower will fail safe, as someone can look out of the window.

Regards,

Richard.

Thread: CNC Utilities
18/05/2017 16:36:15

The bar diameter is set by the start point, and it assumes the start point is at the right hand corner of the bar, as shown on page 1 of the pdf help file. The units have to be consistent throughout, and all entered radii/diameters all have to be radii or diameters.

The ER collets all have a minimum bar diameter the 'collet number + 1or2mm', eg ER32 min dia is 33mm

Hope that helps,

Regards,

Richard

18/05/2017 15:17:36

I have now done a similar program to the general taper program above so that you can add an ER collet shape to whatever you are turning for fitting in a mill/lathe etc and be certain about it's concentricity. The collet shape could then be cut off when you are done with it.

The collet sizes are ER 11 to ER 50, and by means of text editing a .csv file, you can add your own. It comes with a 4 page PDF help file to show what the resultant shape will be like, the machining sequence and a toolpath plot for an ER25 collet for verification.

The principle limitation is that the toolpath does not include cutting the ER collet ejector ring groove, but it does add a comment specifying details of the groove. Comments can be turned off as the toolpath can easily get up to 300+ blocks depending on bar diameter and depth of cut. A relatively laborious, 5 stage cutting method has been used to maintain maximum bar stiffness for as long as possible.

The program is a 32 bit Windows program, definitely runs on Win 7, and probably any 32/64 bit windows compatible OS. It probably runs under WINE on Linux as the other programs do.

The link to the download is: **LINK**

Hope it's useful to someone. I will eventually add a page to my website for it, but haven't done so yet.

Regards,

Richard.

Thread: Question on Technical Drawing
17/05/2017 16:43:07

I think what you need to do is to click on the view, right click, select menu option 'Tangent Edge' and then choose 'Tangent Edge with Font' (middle one of the three options). This 'obvious' nomenclature will show lighter, chain dotted, lines where the curved edges blend into flat surfaces or each other. It will give more detail than tangent edges removed and not the level of overwhelming lines when the lines are solid.

Regards,

Richard.

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