Member postings for Muzzer

Never tried it myself but if your printer can print ABS, you can use acetone to smooth the finish. Won't help the accuracy of the final part but depends if you are after form or function. Doesn't sound as hazardous as you might have thought.

Murray

George

I wouldn't really disagree with anything you've said. The bottom line though is that we all had it pretty easy, live in houses that appear to be "worth" a lot more than we paid for them and have allowed the younger generation to be drowned in debt and paid a pittance. In particular, the emergence of this concept of the unpaid graduate "internship" (a US concept) is a fairly recent and contemptible practice. There seems to be talk of apprenticeships again but they were one of the easy cost savings that were made to boost share prices and dividends, so much of the infrastructure and schemes are long gone now.

Many parents are going to have to help out their offspring who would otherwise be unable to afford housing and/or raise families. Which is fine if the parents are in a position to do so.

Harvey-Jones knew that British industry was in decline when he led ICI and was unable to do much to prevent it. Even splitting the different divisions of ICI up and selling many of them off didn't do much more than delay their demise. As you know, neither ICI nor GEC really exist any more. It's a pity that some of the more embarrassing outfits like Rover took so long to vanish but encouraging to see the likes of Jaguar Land Rover doing so well finally.

Murray

To explain the requirement for a heated bed if you want to use ABS, if the bed isn't heated, the material shrinks and peels up and away from the bed, particularly around the edges. Looks like one of those sandwiches that's gone seriously curly after a few days. TBH, the PLA seemed pretty good.

They require a fair bit of fiddling, with periodic dismantling of the head to clear the nozzle. However, the finish can be pretty good once you've got it all set up and got the settings optimised. Both Andrew Johnston and John Stevenson produced some test samples on this forum if you check their albums.

Murray

Russ B

I am with you. When I went to uni it was essentially free and we got a grant. Some students even finished with a slight surplus (not me obviously!). Nowadays, graduates are expected to be grateful to work for free ("internships"? outrageous). and struggle to pay off massive debts whilst watching house prices drift even further beyond their reach.

What our generation and the one before it has done to the current generation of students and young graduates is simply disgusting. It almost makes me wonder if they will introduce compulsory euthanasia for over 70s when they finally get their heads above water. You couldn't blame them.

I speak as a parent as well.

Hope you can eventually find a fulfilling and challenging career in engineering ahead of you. To get paid (fairly well) to do a job you enjoy is a fantastic outcome and one many people would be happy with. We are lucky in that respect.

Murray

Andrew

Interesting. Sounds as if you were trying to tackle a similar requirement - but using the traditional discrete approach. I was lucky enough to get hold of a partly built ZN1040E 5MHz digital counter / timer / display IC based cct with a 10:1 prescaler (50MHz) and a further Plessey SP631B 700MHz prescaler, from a comms company that had started the project and given up. Got that working up to typically 700MHz or so IIFC. For UHF work I used an OM185 (Phillips) preamplifier which had a three stage design on a thin film hybrid construction. There’s a very similar circuit here (see page 57). For operation below 50MHz I used an NE592 video driver (also Phillips IIRC). After some messing about and laying it out a double sided PCB, it was a useful piece of equipment. This would be the late 70s when I was at school.

Not long after this, I managed to get hold of a development Farnell Instruments MSG800(?) Modular Signal Generator which was the still-born predecessor of the more successful PSG1000 (1GHz) closed loop digital UHF signal generator. I finally got this working from 100kHz to typically 800-850MHz with 1kHz digit resolution. The tricky part was the phase detector – I was able to graft one from the later PSG1000 into it and finally ended up with a very useful piece of kit. Although I was working in the SMPS dept at the time, we shared the same building (and stores!) with the RF boys, which proved handy.The MSG had a variety of modules including AM and FM modulators so you could actually use it as a transmitter when coupled up to a suitable power amp. I used it to drive functional scale model experimental directional aerials at 800MHz, rather than try them out in full scale (these were for HF and VHF). At that frequency, you could simply construct working aerials with copper wire and a soldering iron on the bench top. I mounted them on a motorised revolving base so that the directional gain could be displayed directly on an X-Y scope.

Murray (formerly G8XCN)

How bizarre. I'm not planning to buy shares in any UK company selling those systems. The cost of wearout must far exceed loss and theft. Which is probably why many supermarkets don't even bother using the coin interlock at all.

Merry

Fascinating video, Steve. Did this work continue to evolve into what we have in today's manufacturing environment? Not my field at all but there was clearly some staggeringly complex work going on there. Fault tolerance, standardisation, validation etc - all vital groundwork.

Funny but perhaps not surprising that the Mercans would gravitate towards cable-style comms which was prevalent in their country at the time. Where did the Japanese fit in - did they have another system or follow the US lead?

BTW, the "alternators" shown near the end in the Magnetti Marelli factory are not like any I've ever seen. They look remarkably like throttle bodies to me. Artistic license!

Thanks for sharing.

Murray

I think you'll find that the vast majority of early 3D printers were DIY builds. Originally they were called "reprap" printers, as they were able to print themselves and thus self replicate.

Nowadays, I suspect the majority are still DIY build and the machines being built now include routers, laser cutters, milling machines and more. Where printers stop and these other machines start is very blurred. Try typing words like "CNC" and "DIY" into a search engine and stand back. The parts are readily available on ebay, AliExpress, various online stores and elsewhere.

Some printers are available as kits or ready assembled, some only as kits. You can design your own from scratch. Depends how much you want to do yourself.

Murray

As you aren't going to be able to make an accurate measurement of the power directly from the electrical load, any measurement is going to be based on measuring the torque of the wheel (by measuring the reaction on an arm) and multiplying it by the speed. Just how you vary the load is up to you but the "turbo trainers" (wheel driven fans) are simplicity itself, so why reinvent the wheel(?!)

To make the measurement vaguely manageable, generally a dyno will run a constant speed or constant torque control loop. This then allows the other measurement (torque or speed) to be read off and measured directly as power. However, regardless of how you vary the load, you presumably need to consider how you would measure the power, which is the whole point of the exercise apparently. Going the sledgehammer route, perhaps an Arduino / R Pi etc could be used.

Murray

Never seen a trolley with any form of interlock. If the token is only 1 pound, it's hard to see why an interlock would be justified. Perhaps if you were talking a tenner or more it might make sense - but what kind of place would require that?

At Aldi the other day and the assistant lent me her key (from a corned beef tin). rather then give me change. Once I'd released the trolley, she got it back.

From a design point of view, if you insist on making something, the token should be oval so that you can get your keys off after releasing the trolley. Especially if you are not obliged to return the trolley to the trolley park.

The simplest solution is to use your car key to release the trolley. Once you have got the knack it takes a split second. No need for anything fancy then!

Merry

We always use those adjustable pipe grips / water pump pliers with the stepped adjustment. Quicker than screw type crackers and can be set for small and large nuts so you avoid pulverising the innards. Good engineering solution, yet one that the rest of the family also find easy to use!

My mother who has less strength in her hands uses an ancient, tiny vise mounted on a wooden base with a dished area for the shells. I believe it belonged to my great grandfather who was a journeyman carpenter - family heirloom.

Murray

Back in 1991, BT were planning to "roll out"(yuk) high speed optical fibre across the UK. But Thatcher felt that it was more important to break up BT's monopoly than to build an infrastructure for the future (and possibly concerned about its impact on the BBC) so she put the kibosh on it. Classic triumph of so-called free market forces over national interests. Think where we'd be now if we'd got proper internet back then instead of 56k dial up!!

Particularly irritating and ironic to see that (our) tax payers money is now being used by her ideological offspring in government to advertise "high speed internet" on giant posters all around the country. Why do they need to do that?

Rantworthy

Edited By Muzzer on 22/12/2014 13:50:54

Always make sure you back up your NAS to an external drive regularly. Most NAS's include the ability to backup to an external drive. You might think that using multiple drives in RAID config will protect you but I can tell you from my own painful experience that this isn't the case. Listen and learn.

My original Qnap NAS had 2 x 500GB drives in RAID1 (mirrored, redundant) and gave good service for many years until the power supply started to fail (presumably the caps started to dry out). The first I knew about it was when both drives became bricked. This shouldn't happen with a RAID system surely? One of them was completely trashed and the other was only accessible by removing it from the NAS, mounting it (EXT3 format) and manually copying each directory to an external drive. If I went into a corrupted directory, the PC would BSOD. I had to work this recovery process out myself, as the forums were of no help at all in this instance.

I only recovered about about 70% of the files added since the last full backup and lost quite a few hours in the process. Not long after replacing the PSU and both HDDs with proper "enterprise" grade drives, the fan failed (bearings had dried up) and the OS became corrupted, trashing the data again. It's now in the back yard waiting for a trip to the dump.

The HDDs now reside in an Asustor AS-202TE (2 drives in RAID1). I lost faith in Qnap personally. Although I'm sure they are fine nowadays, I decided to change to another brand.The latest NASs have masses of apps and extras built in, such as media servers, browsers, HDMI, multiple USBs, wifi, webcams etc. I plugged mine into the TV with an HDMI cable and now use it to watch BBC iPlayer, Youtube, browse photos and play music (no PC required). Not bad for under 200 quid. You can access it from anywhere with an internet connection using the apps that come with it and it even sets up port forwarding etc automatically. Mine is an Asustor but the offerings from Qnap, Synology etc offer very similar features. I always back up to an external drive every month or so and back up critical stuff to a cloud drive.

Murray

Bri

Do you know what grade of insert you were using and what material you were cutting and how? There are lots of different grades and shapes as you know, depending whether it's for intermittent or continuous cutting and the material itself.

Cutwel sells exclusively Korloy AFAIK. Not had any problems with them myself and have been pleased with the parting tool which was my original reason for getting more inserts. Having said that, my Bantam probably isn't in the same league as your machines at work.

Murray

Used to be a time when you had to remove your engine and / or strip it down as a matter of course because they were so crap - I know because I spent years doing it myself. Nowadays most cars reach end of life without even the head needing to come off. If you buy a decent vehicle (dare I say something like a Honda, aka "the engineer's car", it will barely need you to lift the bonnet other than to top up the washer fluid. That's despite all the advances that have given us much better fuel consumption, almost zero noxious emissions and much better performance, safety and refinement.

There was once a time (back in the 70s and 80s) when you could lift the bonnet and see the road between the engine and the body. Now the engine bay (and the underarches, bumpers etc) are chocablock with stuff. The improved reliability comes despite that increase in complexity. Pretty amazing what has been achieved - by engineers of course!! It's nothing to do with the EU but instead the constant march of progress.

I've done hundreds of thousands of miles in my various Hondas without the slightest problem. I may have been luckier than some owners but by and large it's simply down to good engineering.

Murray

Interesting! That looks pretty good. Hope you'll tell us how you get on with it!

It appears to be a cut down version of Spaceclaim. I've no experience of that myself but it looks as if it's a pretty capable professional 3D CAD system.

Murray

Edited By Muzzer on 18/12/2014 12:47:25

I bought a fairly nasty Chinese-made 4" belt sander last year for peanuts and it is fitted with an alleged 1/2 hp motor. I wouldn't go much lower in power regardless of the belt width, as you can take a fair cut with a new belt and this can be helpful if you are rounding parts off. The main problem is the heat build-up in the part. You need gloves and a water container to keep dunking it in, rather like when you are grinding tool bits.

Mine has one of those belts that can be tipped vertically. I find both positions useful. Dead handy tool!

Murray

Loosen the drawbar 1-2 turns, hit it hard with a mallet and don't overtighten it again. Doesn't get much simpler!

Just suffered some voluntary finger spasms when surfing the Cutwel website a few minutes ago. Order was dispatched within 10 minutes of said spasms. They promise free next day delivery before mid day for orders placed before 6pm. I'll be able to fiddle with these in my armchair tomorrow. Fast service!

Murray

With my mill/drill (MT3), I would loosen off the drawbar about 1-2 turns and bash it with my plastic headed mallet as the normal means of release. That would stop the chuck falling out.

If I'd overdone it, I had a nice old spring loaded slide hammer of unknown parentage with a taper end that fitted in the extraction slot in the quill. However, I soon learned not to overtighten it in the first place so this wasn't something that happened frequently.

The other, more direct method is to remove the drawbar and drop a length of steel (brass?) bar into the hole from increasing heights until it releases, achieving a sort of slide hammer effect (piece of wood to catch the falling chuck etc). If anything gets damaged it's likely to be the MT adaptor rather than the machine itself. But one smart tap with the mallet was normally enough.

Murray