Member postings for Nick Wheeler

Front mount through bolts are considerably easier to mount to a new backing plate:

Turn the register so you're happy with the chuck fit.

Clamp the two together somehow

Mark through the chuck mounting holes

Drill and tap

Bolt the two together.

Minimal measuring and awkward marking out required.

Bolts should never be used to locate anything, although we all do it. Dowels, pins or machined faces(the register on a chuck backplate for instance) are required for precise location.

Edited By Nicholas Wheeler 1 on 31/01/2021 20:53:58

Americans use Prius electric steering columns to add power steering to manual boxes. We tend to use Vauxhall Corsa ones because they're small, cheap, and readily available.

You can't just bung a rack in instead of a box, because there's a lot of geometry that needs to be right. Assuming there's even space to fit it across the car. BMW used steering racks on the E39 5-series, except on the V8s for this reason.

Edited By Nicholas Wheeler 1 on 31/01/2021 09:25:17

I agree with Andrew.

I would use rather more than 30thou DOC too; even a mini-lathe will happily manage double that.

I do the same for all the same reasons. An ordinary stamped washer is so cheap that I would need a good reason not to use one two.

They're all engineering.

In 3D.

Model Engineering would be far better if we replaced Model with another term. Hobby? Home? Small? Craft? Or just ' '.

How about coach builders? Boat builders? The joiner that built the circular staircase in the corner? Can we really afford to exclude everything that doesn't have a toy steam engine?

Unfortunate for whom?

I bought a set of 8mm shank carbide tools for my mini-lathe, took them out of the box, adjusted them in tool holders and used them satisfactorily for years until I replaced the machine with a WM250 that I fitted with the same QCTP and tools. A couple of times a year I'd be hoodwinked into wasting time and HSS by grinding my own tools. After all, it's an essential skill, and is unfortunate not to be able to do it. In all that time I ended up with one that actually did everything it was supposed to. All the others look like they were gnawed off by an angry rat, and some of them sort-of worked.

Too lazy to learn about tool angles? Hell, I even tried scribing lines on each face to 'help.'

Am I afraid to try it? No, but as I have tools that work for no effort, it's not a priority. That's time that would be better spent learning all the leads of Cambridge Minor

I had an hour week for a year 'learning' Technical Drawing when I was 14. That was 36 years ago and although it's left me able to read a drawing, I can't manage to create anything more than a rough sketch.

What makes 3D CAD a breath of fresh air is it eliminates the need to know how projections relate to faces, scale to fit on the page, work out geometry for awkward shapes, calculate origins/depths/distances or all of the other techniques that try to represent a 3D object on a flat piece of paper.

Instead you make a rough sketch(Fusion 360 even calls it a sketch) of the basic shape, constrain it so it stays looking like it should, add dimensions and extrude it to a solid. If you make the sketch over the mating part you already built, you can use its dimensions so everything fits as it should even when you make changes. Knowing it's a bit of square material with a hole in it with a plate bolted to each end is how you'll make the part is also how to model it. My grinder head was built around the 20mm diameter post and a layout sketch for it and the spindle axes; if I change the distance between them on the sketch, all the other parts alter with it. I actually did this to bring them as close together as space allowed. The rest of it started with an externally modelled ER32 collet chuck, then its holders, slide, pivoting base, work table, uprights, pivot, linear slides and finished with base, trimming and adjusting sizes as I went.

Animating the joints has shown that the table doesn't need 45 degrees of tilt in each direction which will make cutting the locking slots easier. There will be other changes; the rails for both the grinding head and tool slide are currently to be L-shapes milled from solid; I'll be changing them to two sections bolted together with the fasteners needed to attach them. Looking at it, I don't think it needs to be made from 10mm steel sections or a 6mm thick table. Reducing those would mean less work and material cost.

I could create drawings for each part from the model, but they're deliberately simple so isolating the part to work on and displaying the dimensions directly on it will be enough for most of them.

I've had no training in CAD, but have been modelling most of the parts I've made for the last couple of year to learn about it.

Edited By Nicholas Wheeler 1 on 29/01/2021 13:14:32

Model engineering is a terrible term for my workshop time.

I've spent a bit of time designing this recently:

That's a fully animated model, and I wish you'd told me before I did it that it's not going to be suitable for a 'model engineer.' As you can see, it will use bought in parts, parts I could make but won't, the belt cover is to be 3D printed because it will give a better part than the sheetmetal one I could make, and so on. There is no way I could have come up with this without 3D CAD, as it shows various issues that weren't obvious as I went along. I'm now looking at the design to reduce some of the features to make it easier to build.

Edited By Nicholas Wheeler 1 on 29/01/2021 11:01:14

You'll have the part you wanted. Made by an efficient process, freeing up time to use doing something that can't be done like that. Just like bandsawing your blanks compared to cutting them with a hacksaw.

Making things is a means to an end. If I just wanted to make things with my hands, I'd take up whittling scrap wood with the pocket knife I've owned for years

Your friend will paint them with 2-pack automotive paint. If you don't want a metallic finish, then a direct gloss system will be at least as durable as any of the more traditional paints used on machinery, and won't need a clear coat. Which saves labour and material costs. 1/4litre of paint will paint half the side of a car, so you won't need much paint!

I wouldn't paint workshop equipment with anything else.

I wouldn't want oil in the compressor tank for all the reasons stated.

Oil in a sump isn't pressurised much, and doesn't have much oxygen to allow it to burn. That isn't the case in a tank of compressed air!

If used air tool oilers are fitted to the tool, after the airline connector. From what I've seen, most light users don't have them and rarely oil the tools manually.

Cardboard and duct tape prototypes until you've designed something that works and doesn't get in the way of working

Not much different from 70's BL cars, which were assembled from fasteners made from an engineering grade of cheese. A French one, as they were soft and weren't usable for long

Dave, your representation of a defect in a round tank is the wrong way round; the wide part of the V should be on the inside. Which would make the pressure pushing outwards even more effective at enlarging it.

Ever tried it with a small(ish) compressor? Makes for a much less consistent air supply at the gun, which is the last thing you want when spraying. And the compressor runs all the time even when painting small panels.

Because a twist drill doesn't make a particularly good hole: it be round or accurately sized. Reaming after drilling improves both.

I wonder how just effective a compressor would need to be to rupture a typical welded steel tank in good condition? Mine's driven by a claimed 2Hp motor, and a fairly small compressor head; I doubt that could do it.

These failures are not caused by the compressor operating outside its design, but by the material of the tank failing. That's largely due to the tank rusting internally due to the water in the compressed air, and is why any compressor pressure vessel should be drained frequently and inspected regularly. That often doesn't happen in professional workshops and hobbyists are even more lax.

My 30 year old SIP compressor needs a new starter, is even noisier than it should be, and takes far longer than it used to fill the tank. I've been considering stripping it and replacing all the worn parts, but this recent spate of videos and posts across several forums have convinced me that I'd be better spending a little more cash on a new one, and saving the time for something more productive. That's a chance to get one more suited to the paint spraying which is my main use - I only use air tools when a decent electric(battery for preference) equivalent isn't available

Edited By Nicholas Wheeler 1 on 24/01/2021 11:24:19

Tug, I agree that the commercial clamping sets are far too big for small mills; they can be a real struggle to set in place and work around. Making a set based around M6 fasteners with stackable packing pieces and a consumable sub-table has been on my list for some time. I also intend to make matching T-nuts for the faceplate slots, but as I've only used it once in 18 years that's a very low priority!

As for teaching, it's a depressingly under rated skill. Good teaching takes training, practice and an understanding of the subject - I suspect those who trot out the phrase those who can't, teach have never tried it. There a lots of people who can do, but are hopeless at teaching. That teaching also develops your skills as you do so is so well known that it has a name - The Mentor effect; having to think through what you're doing and why so you can explain it is very useful. I found being asked to help train our new bell-ringers is the biggest improvement I've made to my own ringing.

Blimey Dave, are you me? Those two points are exactly what I was going to write.

I suspect that manual tool grinding is one of those skills that is better acquired with an practised voice over your shoulder. I didn't have that. and bought a set of the much derided cemented carbide tools with the lathe. An hour after getting it home I had made my first two parts and bolted them in place, despite not having used a lathe before.

The problem total novices have is they don't know what they don't know. They could spend hours grinding tools that don't work consistently - the bit that matters - or even at all. Buying tools that will work straight out of the box is a huge and immediate boost up the learning curve. If a grinder isn't already available then the £40 saved will buy a considerable amount of material to practise on, which will be necessary whatever approach is taken

Being able to grind your own tools is an essential skill, but there are others that are more important first: safe practices, secure work holding, tools on centre height, order of operations etc.