Member postings for Jelly

There's a blanket exemption in the gas safety regulations for self propelled vehicles, other than those used for hire or reward, so trains or traction engines would be in the clear (although the boilers would obviously still be regulated as pressure vessels).

It's less clear on stationary steam plants, the gas safety regulations only apply to installations connected to mains or "Gas Storage Vessels" (which is defined as refillable containers only), so using a disposable cartridge would put you in the clear.

Beyond that the manufacture of gas boilers is not in scope of the gas safety regulations, and instead falls under the Pressure Systems Safety Regulations, (as do other boilers)...

However making a gas connection other than between a gas installation and portable "Gas Storage Vessel" is in scope, so any pipework which isn't integral to the boiler design could be argued to be in scope of the regulations.

Making your own custom gas storage vessel would be again in the scope of the Pressure Systems Safety Regulations or the Carriage of Dangerous Goods Regulations, depending on if it is integral to the equipment or separate, both of which would be a lot of hassle to comply with, although not impossible if you're determined.

Edited By Jelly on 16/03/2023 22:26:42

In fairness actually, the M12 thread would be substantially stronger than the M6 thread used to turn the half-sized one and not using a full profile form tool would also reduce the cutting forces substantially...

I don't think I've seen a ball turning attachment with a 60mm capacity before though, but once one was built, it would be substantially more useful than a fixture to hold 60mm spheres or 40mm hemispheres.

Edited By Jelly on 16/03/2023 18:24:09

So I was looking for something on one of my external HDD's and happened across the 3d model of the main body of something I made as a gift for a friend years ago (there are some other parts which turn it into a little bird).

I've just produced a little drawing of it as it's a really interesting part, which produces lots of challenges:

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The one I made was actually ½ scale, and turned from a cylindrical piece of brass on a M6 threaded arbour, the curves roughed in with chamfers, and the final shape generated with a (gigantic) carbon steel form tool shaped to produce the full profile.

That very direct approach was easy on the work-holding front, but an absolutely bonkers way to go about it in just about every way...

Something which I came to fully appreciate as the process resulted in innumerable scrapped parts, several snapped arbours and at least one malformed brass bird being launched bodily across the workshop.

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I quite fancy making another full-size one for myself, but learning from the previous failures, I can recognise that there's a risk of having a 1kg hunk of brass launched at me, which I'm not really up for.

Thankfully in the intervening years since I made the last one, I have also become slightly more imaginative (to go with the risk aversion) and have been able to come up with a few different approaches using to try which I think would result in a decent outcome, all of which involve making a jig/chuck which can hold onto a sphere securely, and pose their own problems in terms of driving the workpiece and/or marring the surface of a finished part due to clamping pressure

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I am however curious how others would approach this, because on first inspection it's far from simple to even hold on to the thing.

Where is that set out in legislation though and what does it say specifically?

It's not just out of line with market conditions, but it is also clearly at odds with how the power distribution grid in both rural areas and urban areas with large amounts of light industrial units interspersed with housing (Birmingham, Manchester, Sheffield) functions.

Edited By Jelly on 16/03/2023 10:26:45

What's the implication of running equipment which meets the relevant standards for Class A (Industrial) but not Class B (Domestic) in a home environment, it's not clear from a cursory search what duty (if any) to control for EMI from CE marked equipment is placed on the end user, or from which law(s) such a duty would originate.

My plasma cutter is a 50A ESAB jobbie, the manual declares that it is designed to EN50199 (Electromagnetic compatibility - Product standard for arc welding equipment) for conformity with 89/336/EEC (the EMC compatibility directive), so in principle is it is an entirely compliant device, but it very clearly falls into Class A.

When the DNO visited to discuss putting in a 3-phase supply, they didn't bat an eyelid at the equipment, because from a network perspective my utilisation levels and number of starts was well below that of several light industrial users connected to the same substation.

I would also be interested to know if running off a Gen-Set decreases or removes the problems, or if it's actually RF emissions which are the issue (as with HF start TIG welders).

Edited By Jelly on 16/03/2023 01:31:09

This is a good point which is often overlooked in a home workshop, for an occasional user a PAPR headtop is probably a bit much, but at least buying some metal fume rated disposable masks would be a good idea.

This said, for anyone who welds frequently or for long periods they're worth having. I bought a second-hand 3M Adflo which is hands down the single best purchase I have made for welding, massively improved my comfort levels whilst also protecting my lungs, what's not to like.

I also installed an LEV system (albeit home made) which is essential for arc-welding inside as the fumes from burning 30 or 40 cellulosic rods in quick succession will totally overwhelm the workshop without the ventilator running.

All this said, I tend to do plasma and flame cutting outside due to the sheer volume of sparks and molten slag produced.

Popped over to see Ian (of this parish) in my lunch break and then sorted out my lathe topside this evening with the dovetail bolts he kindly made for me.

Followed up by going to turn down some socket headed cap screws to replace the existing wallered out ones on the lathe, and immediately breaking my last insert of the type I wanted... I went rooting around in my drawer of HSS toolbits and couldn't find anything with a suitable grind, so decided to quit whilst I was ahead for the evening before inviting a third disaster over on the grinder.

At which point I narrowly dodged the third disaster again, after deciding to give the lathe a birthday with new oil in the headstock, but realising just in time it would be a supremely messy task done as I initially envisaged...

The position of the sump plug is such that the extremely thin (ISO2) bearing oil would go jetting out the side and splatter absolutely everywhere if I used an oil-pan, so better done using a transfer pump (or at least buying a dedicated bucket which gives me a fighting chance).

Tomorrow will hopefully be a more successful day.

Edited By Jelly on 15/03/2023 21:13:31

The graver rest looks great, nice work!

I have successfully turned screws as small as BA12 (1.3mm?) on a Super 7, but it took quite a bit of practice and scrapped parts to get the feel for it, as well as grinding a HSS tool with an almost dead sharp nose radius and lots of rake to minimise cutting forces (a tangential tool would do a good job actually).

I would think that as you're already proficient with the graver it will be faster to stick with that technique, even though it is possible to use the compound/carriage feeds to do it.

It is my strong suspicion that TOS used nuts, and straight nuts at that, very deliberately as a sacrificial part to prevent over-tightening from damaging the cross slide.

The three contact points between the nuts and the circular dovetail creates a significant stress riser directly through the thinnest part of the wall, creating a failure point which is immediately obvious to the operator, and the cross slide is designed to make them easily replaceable without any disassembly, just wind it out fully and pop them in from underneath via a little pocket.

Again, it's not that I didn't think of it, but I didn't have any suitable stock, most of what was to hand in sane sizes was either too weak for such a highly stressed design (brass, copper) or too hard for sensible hand working (817M40 pre-hardened, or EN24W in old money) without ruining tools prematurely.

If I was going to have to buy steel I wouldn't normally use, then looking for the parts themselves seemed just as sensible.

A big thankyou to Ian who has made this much easier than anticipated.

Edited By Jelly on 14/03/2023 11:56:23

This was my initial thought, until I realised I'd used all my M12 threaded bar.

Ian, You're a very kind bloke (who now has a private message with some drawings)!

My lathe started suddenly making a lot of chatter this evening after adjusting the topside angle.

Tracing it back two of the dovetail nuts which connect the topside to cross slide have snapped in half at their weakest point. Looking at the break they have been failing for years, and clearly decided that being re-tightened tonight was the final straw.

As a complication I was making a new drawbar for the Harrison at the time (it has needed one since I got it and has now deteriorated to the point of being unsafe) so the mill is also out of action.

I cannot for the life of me find any UK suppliers of dovetailed nuts (or bolts), other than for decking purposes, any suggestions?

This would be my preferred option normally, but I get the impression Sonic would want to use it as a welding table.

An application where I have learned from experience that you can get wood smoldering hot underneath a large metal plate intended to protect it if you're doing a lot of bigger welds in PA/PB (flat) position with the back of the workpiece in direct contact with the table.

Edited By Jelly on 13/03/2023 12:37:51

I would suggest:

• Welding on 50×50 tabs to your 4×50 bar, ideally so once assembled into a frame there's one in each corner, with one in the middle of each short side and two at ⅓ and ⅔ along the long side.
• Weld up the frame with the 4×50 bar and 100mm tube on as flat a reference surface as you can (your workshop floor looks quite flat in photo's you have shared.
• Flip the frame over and place both pieces of steel plate on the frame, line up and clamp in place.
• Using a hand drill, drill 7mm holes through the plates and the tabs.
• Take the plates off and tap the hole in each tab with an M8 thread.
• Drill out the holes in both plates to 8mm, and countersink.
• Bolt the plates down with M8 countersunk machine screws.

Et Voila, you have a flat sturdy workbench with a 5mm thick steel top.

If you want to improve rigidity, there are two upgrades or one change you could make to your existing design:

1. Add further braces in the middle going the other way to your existing ones when welding up the frame and put some extra tabs (& bolts) in the middle where the braces meet. If you do this: drill, tap and bolt those holes in the middle first, then drill the outside ones, take the top back off and tap the outside tabs, and re-assemble, to reduce the risk of a misaligned hole causing the plates to warp.
2. When you weld the frame up, add additional braces to the legs about 100mm up from the floor to stop them splaying outward, they can be between the legs at say 100mm off the floor (which would allow you to put a plywood shelf on it) or at a 45° (which is better if you want to put boxes of stuff or a small welder/compressor under it.
3. Make it 1m×1m instead and use both plates bolted down together to make a 10mm top.

Edited By Jelly on 13/03/2023 01:07:38

I have known someone do this with 2 × 40ft shipping containers, bought a "contract lift" from Ainscough to pick them up off a truck in the road and drop them behind his house, done at 2AM to minimise disruption to traffic.

It wasn't expensive relative to what he was doing (buying two refurbed containers as an alternative to having an outbuilding constructed), but it wasn't an inconsequential amount of money either.

Unless Simon is good pals with a crane owner, I probably wouldn't bother asking as buying a cheap shed would be more economically.

As an aside, caravans (and portacabins) inevitably suffer horrendously with leaking, leading to intractable issues with damp, mould and fungus as they deteriorate with age, and I wouldn't personally consider using one as a storage unit for that reason.

Nice work!

That looks like it was really very awkward to accomplish, so I hope you have a suitable sense of satisfaction at your achievement there.

[Double Post]

Edited By Jelly on 12/03/2023 12:15:09

Try emailing Accu?

They will make small orders of custom fasteners on a couple of day call-off and the prices are reasonable for that level of service because convenient low volume just in time manufacturing is literally their entire business model.

I haven't because it's still sort evolving and I have some other projects to finish before I start working on it in earnest, which will give me an opportunity to prototype doing some of the more awkward bits.

I'm also still resolving between getting castings made or fabricating certain parts as a design decision as well.

I will probably start a build thread when I get underway in earnest.