Here is a list of all the postings Chris Gill has made in our forums. Click on a thread name to jump to the thread.
|Thread: Issue Reading New Digital Viewer|
Sorry to say, I also find this new viewer unusable. As with others, the whole point of my digital subscription was to be able to use the archive. I often find I have to print to PDF so that I can enlarge some of the diagrams. I hope someone has a serious re-think.
|Thread: Learning CAD with Alibre Atom3D|
After lots of messing around I finally managed to model something I may, one day, try to make.
I even got the various items working and it highlighted several small problems in the original design. Thanks for all the expert comments on this thread.
I have to admit I do keep hitting frustrating problems - reference lines that don't stay put and may vanish without trace, stack dumps and sketches that were editable before I clicked Save and then become locked in some way. Looking on Alibre's forum it seems even the professionals are having problems.
I was trying to think of a way to do that and kept getting it muddled up. That solution looks perfect
I may be missing a trick, but ...
I'm trying to model the top end of a piston rod. It consists of a cylinder with a slot cut most of the way along its axis. Then it has a hole drilled (extruded) through near the top. All OK so far.
Finally I want the top to have a half-round profile when viewed from the cross-hole side but square when viewed from the slot side. I've tried chamfer and fillet but, of course, they apply all the way round the edge. Is there a straightforward way to do this? Or do I need to create the top using separate sketches and extrusions?
David, Jason - many thanks. I read that lot three times and still missed it! And now for my next screw-up ...
I've only just installed A3D but I've made it through the on-line tutorial (that 100-page PDF) and the first two parts of the MEW series. In part 3 I keep hitting a problem.
After creating two circles and three lines I created two tangent constraints and a dimension followed by trimming the excess off the lines. That leaves me at figure 7 but when I try to deactivate the sketch or extrude it, I get an error saying there are open loops. Selecting the "open loop" in the list of errors highlights the intersetions between the horizontal lines and the outer circle. I don't know if it matters but the tolerance is shown as 0.01mm.
So far I've tried three times without success. Does anyone know what I'm doind wrong?
|Thread: What did you do Today 2018|
Just to prove nothing goes to waste ...
Here's my rendering of Andy Johnston's headstock handwheel (MEW Autumn special). All materials from stock and the piece of wood was left over from making a new seat for a commode. It could have given someone a nasty surprise if I'd left all that metalwork attached!
|Thread: Why did the tap stick?|
Sorry if I didn't reply to some of the suggestions - I had a couple of days away. Not a nice jaunt though - crammed into a corner trying to do a decent job of plastering around a load pipes without sticking my foot in it or plastering myself!
As always, something I thought was a simple job turns out to have many more aspects to it and I'm really grateful for the wealth of knowledge people are willing to share.
I used a light oil as a lube so that it wouldn't gum up but I never thought about how it handles pressure. OK, lesson learned, I'll add something better to my shopping list.
Given my uncertainty about the tap, I've got a decent set on the shopping list as well. I only had the one but all the others have worked well for years.
I drilled the hole with 8 then 8.6 (Dormer precision drill) and later 8.7 so I'd expect the hole to be very close to 8.6 / 8.7. I don't think my tap was off-axis but I'm perfectly capable of fouling it up! I've seen a drunken thread before, courtesy of yours truly.
Wow, thanks all. As ever, some real food for thought.
Just to respond to one or two - the work was in the lathe chuck and hadn't been moved since drilling and the tap was lined up in the tailstock. Although I said it was a taper I was wrong - it was a general purpose tap (shorter lead). I lubricated with 3-in-1 (always seemed to work in the past) and I always reverse at least once per turn (depends on tap size)
As for scaffolding ... I once had a Landrover serviced and some idiot used the wrong torque on the wheel nuts. I couldn't shift them so I went back and complained. They couldn't shift then even when warmed up with an oxy torch so they sent me to the nearest lorry service place. They simply attached a socket and bar, a long length of scaffolding and then jumped up and swung on it until the nuts came loose.
Aha! Didn't think of the blunt tap option - just assumed it was good. Sadly my grinder is just the off-hand type with wheels that tend to pummel things into submission.
I'm really hoping the 20mm-deep hole is straight, otherwise I've got serious problems. Though I can see the logic of that with much deeper holes.
I was trying to tap a through hole with a 3/8" UNF tap but it got stuck half way.
The material was a bit uncertain but probably EN8 or similar (based on spark tests). The tap was an HSS taper tap, the pilot hole was 8.6mm (about 70%) and the hole was supposed to be about 20mm right through. But after around 11 or 12 mm of reasonably easy progress it stuck and was difficult to withdraw.
I'd already backed it out and cleaned it once and no end of cleaning made any difference. I tried opening the pilot hole to 8.7mm but it didn't help much.
My thread gauges agree the tap is 24 TPI (though they aren't as long as the tap) and a 3/8" bolt went into the hole easily to a point. I wondered if I'd managed to work harden the steel but it turned, drilled, knurled and parted quite nicely.
When I set the tap against a bit of threaded bar I discovered that there was a tiny discrepancy that looks like the tap is fractionally less than 24 TPI.
To my mind, if the tap isn't quite right it should go through the hole and the bolt should get stuck.
The tap is part of a set I bought years ago (UNC, UNF, MC, a few MF and others). This might be the first time out for this one but the others have been brilliant.
All I can think is that the pitch changes slightly along the length of the tap but is that feasible? Or have I missed something blindingly obvious?
Thanks in advance ...
|Thread: Mogens Kilde's Double Diagonal Engine|
The series started in ME 4383 - 30 July 2010 and ran through to the end of the year (4383, 4386, 4388, 4390, 4392, 4393 and 4394). Have fun
Geoff - it needed a good head magnifier, which meant I kept crashing into the lathe chuck (no milling machine)
Neil - I'm intrigued already. I guess I don't have long to wait
This little engine was certainly a challenge, not least because of the frequent need to make another tool. Still, I learnt a lot and probably swore just as much, especially when a tool jam shattered the first crank shaft. Thanks to Mogens for the original series.
Here's a link to a short video and a few pics .
Can you spot the crank shaft template in the above pic - I made it from my old corporate Amex card!
|Thread: A New Way to Injure Yourself|
My favourite claim to stupidity involved a 14lb sledge hammer and a washing line. Unfortunately, I only remembered the washing line when I was face down on the lawn with a bruise on the back of my head. Didn't do that again
|Thread: Helping dad vertical engine|
Thanks for the PM.
They've been interesting projects - my first two engines. Which means I've been learing a lot and making all the usual mistakes (I assume). I was thinking about a half-beam engine next so number three looks spot on.
I finally finished all the painting and reassembly. If the real thing ran at the speeds I got out of this little model it would have torn the building apart! Here's a pic you might like (not got to grips with posting to YouTube yet - strange the skills you have to acquire to get into engineering).
Incidentally, you mention a third engine in the series - did it ever get published? Thanks
Will do - it's stripped down for painting at the moment so it'll be a few days
It runs! Just got to make a nice base, clean up and paint it.
The first attempt ended with a loud bang. Then I realised I'd connected to the unregulated side of the compressor and the short connecting pipe had migrated to the other side of the garage. Ho hum
|Thread: Inlay with iron-on veneer|
Everything I came across seemed to suggest veneer was shipped flat so it's good to know it can be rolled for delivery. My remaining stock is very old (inherited) and crumbles when bent much
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.