Here is a list of all the postings Robin Graham has made in our forums. Click on a thread name to jump to the thread.
|Thread: Polishing Brass|
Ian. I have spent many hours polishing brass trying various methods including belt sanding. I agree with others that belt sanding is not the way to go. There are various problems with this approach. One is that it as you go through the grades, it is necessary to turn the work at angle of at least 45 degrees (preferably 90) between grades so you can see that all the scratches from the previous grade have been eliminated. In your case (unless you have have a linisher with a very wide belt!) this will involve running the work across the belt at right angles. It is pretty much impossible to do that without getting 'dig ins' when the work crosses the edges of the belt. Even if you have a massive belt you won't be able to hold those slender strips down on the belt with consistent pressure. You may also find that even at low belt speed the the work runs away from you - there's a lot of friction and with such thin material you don't have much to hold on to. By all means give it a go, and if you have success please report back - I have never got this method to work despite numerous attempts.
What I do now is old school wet 'n' dry up to 3000 grit then polishing compounds/mops. - I use mops and the Menzerna compounds from The Polishing Shop where you will find information about the various types of mops and compounds available.
Autosol is OK from maybe 1200 or 2000 grit if you're not too fussy. It won't give a true mirror finish on brass though - you will still see scratches if you look hard enough. If you want a specular finish (which I aim for) it's polishing compound, elbow grease and meticulous hygiene - you need to be sure that not a single particle of grit or compound from the previous stage is anywhere near. A flea can jump about 160 times it's body length, a grit particle would laugh scornfully at that.
Obviously I'm a bit obsessive about this, you may be less so!
Edited By Robin Graham on 06/04/2022 23:33:41
|Thread: Why is electricity so expensive?|
Like everyone else I guess have had unwelcome news from my energy supplier - £0.32 per kWh for electricity. Gas has gone up from about £0.04 to ~£0.07 per kWh too. It made me think - given that most UK electricity is still generated by domestic gas fired power stations, which presumably operate at better than 25% efficiency, why are the electrons so pricey?
Edited By Robin Graham on 05/04/2022 01:22:17
|Thread: "Kiv" or Kiev?|
Probably your question has been answered in one way or another Phil, but to put in a nutshell it's because different linguistic signifiers (ie differing spellings and pronunciations of words with the same meaning) are important in establishing tribal, and by extension, national identity. For example, from the King James Bible (Judges 12:5-6)
Then said they unto him, Say now Shibboleth: and he said Sibboleth: for he could not frame to pronounce it right. Then they took him, and slew him at the passages of Jordan: and there fell at that time of the Ephraimites forty and two thousand."
It's been going on for some time! The reason that the BBC has adopted the Ukrainian pronunciation is simply an expression of support for Ukraine's desire to resist Russian aggression and develop a distinct national identity, reflecting Western views I think. No doubt similar support would be given to (some) other countries if their national identities were threatened.
On Cunning Linguists, a little known (but interesting!) nugget is that the late and great Robert Smithies who set crosswords for the Guardian until his demise in 2006 proposed 'Cunning Linguist' as his nom de plume when he was engaged, but the editor rejected it (too near the knuckle) so he chose 'Bunthorne'. One of his best:
Amundsen's forwarding address (4)
That's madly off topic I know, but trying to lighten the tone.!
Edited By Robin Graham on 04/04/2022 02:47:15
Edited By Robin Graham on 04/04/2022 02:57:03
|Thread: Gasless MIG welding|
That's the explanation I (tentatively) came up with myself Noel - thanks for confirmation. Coupled with my poor starting technique it was taking too long to get a very localised area of metal hot quickly. It's a fine line to tread though! I'm not sure why the low amperage works with laying a trial bead on the surface of the box section, but not when making end-to-surface joins. Maybe something to do with the sharp corner of the end 'attracting' the arc - it is always the end which melts away from the joint, not a hole though the 'surface'. Hmm, just thinking out loud...
I have improved things somewhat by clamping the box section to piece of scrap and striking the arc on the scrap rather than the work - that way when I move to the work with the hot electrode the arc starts more readily so I am less prone to be taken by surprise and dither. Speed is of the essence with this it seems.
I'm pretty sure that I'm going to get some TIG gear and try that for future projects. I talked this over with my daughter tonight (she's a psychologist for some reason) and after describing the MMA, MIG and TIG processes to her in detail she said that TIG was clearly best suited to my personality type. So I have a professional opinion to present to the Chancellor in my case for support. I may have exaggerated the difficulty of MMA a little bit ( 'It's like holding an exploding firework six inches from your face and keeping a steady hand' ) but I think her judgement sound.
Anyhow, thanks to all for the comments. they have been very helpful.
(edited to remove unintended emoticons - this site is really bad in the way it interprets standard punctuation)
Edited By Robin Graham on 30/03/2022 02:02:29
Edited By Robin Graham on 30/03/2022 02:06:21
Thanks for suggestions. Encouraged by Clive's response (it should be possible to weld down to 1mm with MMA) I had another go today. I realised that when I strike an arc I instinctively withdraw the electrode a bit then move it back in to correct the arc length before starting to lay the weld. This takes only a fraction of a second and isn't a problem with thicker stock, but it seems to be too long for such thin stuff. I worked on improving this aspect of my technique and had some success, though I had to cut the sticks down to about 4 inches to get the necessary control .
I have now made some ugly but sound welds by laying sort of extended tacks, cleaning up, then joining them. This seems to work - I'm trying to make T joints and it's harder to do the fillets than the sides, but for this project (it's a lightweight frame for a prop horse) I probably don't even need an all-round weld.
I took on board Noel's suggestion that it might be better to up the amps rather than reduce them and that seems to have helped too. I am using 1.6mm 6013 rods and was running at 15A. The recommended amperage on the box is 20-40A, but some guy on youtube told me it was OK to 'run cold' for thin stuff. It seems to work better at around 20-25A. I could lay test beads OK at 15A, but not so good for actual joints. I'm not sure why yet.
The upshot is that I now think I can do this without investing in new equipment , which is good in one way but bad in another - everyone likes a new toy! But as I have now sort of mentally budgeted for this sort of money for welding I think I might have a go with TIG - my MMA machine (Parweld 163) has a lift TIG setting and I can buy a torch and gas bottle/regulator for about £200.
Thanks for the suggestion of the Albee gas Clive - I was thinking Hobbyweld, but the small Albee cylinders are actually cheaper for the gas (because they charge them to 200 bar rather than 137 bar from Hobbyweld)
Mark and David - many thanks for your generous offers of help with this. I'm in Derbyshire, near Matlock, so a bit too far away. Much appreciated though.
I have an stick (MMA) welder which I'm OK with down to 1/8th inch stock, but now I have a job which involves making a frame from 5/8th x 18g (1.2mm) steel box section. I like a challenge, but I'm near to giving up on this!
Probably I'd be better off with MIG but I don't want to invest in gas as I don't do a lot of welding. I had read that gasless MIG was pretty rubbish, then recently saw a review of the SIP 130 Synergic machine by doubleboost which made me think again. It's ~ £300 which is doable but a bit much for a machine which I won't use that often. But there are gasless welders on amazon for less than £100 - maybe they're OK, maybe they're not. They get some good reviews, but you know what Amazon reviews for are like! So I'm seeking some more informed opinion.
Edited By Robin Graham on 28/03/2022 00:34:54
Edited By Robin Graham on 28/03/2022 00:35:19
|Thread: Warco WM14 mill electrical failure.|
Thanks for replies. I guess I can make some basic checks for earth leakage with the multimeter, maybe it is just a dodgy connection. Unusually Sod's law was violated on this occasion. I was halfway though the last of a number of holes which had to be precisely located when the 'event' happened so I was able to finish with a drill press and carry on with the job. Done now, so I'll have a poke about and ask further questions if necessary..
Edited By Robin Graham on 21/03/2022 00:29:52
Don't know what it was, but you may have more success searching on 'luting' rather than 'looting'. Lute is a term for cement, sealant etc I think.
Edited By Robin Graham on 18/03/2022 22:59:53
|Thread: Warco WM14 mill electrical failure.|
I was drilling some aluminium with my WM14 tonight (nothing arduous, 4mm) and I noticed that when I wound the speed pot up from zero sometimes the machine didn't immediately respond then 'jumped' up to speed. This happened maybe three times, then when it seemed to be drilling happily at a stable speed the workshop power tripped (RCCB).
I suppose it's the control board that's gone, but before I contact Warco to ask about a replacement I'd be interested if anyone could tell me if these symptoms are consistent with a failure of the control board, or if I should be looking elsewhere. Are there any tests I can do to track the fault down? I have a multimeter, but that's about it.
|Thread: Help needed to lift bandsaw curse.|
Bill, it might be worth reporting your experience with the Vario blade to Ian at Tuffsaws - he's very approachable, and knows a lot. He'll probably be interested. When I was struggling with setting up my own saws I emailed him and had about two pages of good advice. I buy nowhere else now!
|Thread: What are these connectors called?|
Well, this has been an eye-opener. I bought a box of connectors (DuPont and JST) together with a new crimping tool which works with both. £35. But not quite right for what I wanted to do or the wire gauges I had to work with. So I investigated further. JST have a range, according to their website, of more than 30,000 styles. Then there's Molex and others. The right things must be out there, but this rabbit hole is too deep for me.
I shall resort to the trusty soldering iron as Mark advised, and heat shrink.
Thanks for all the advice though - it's been an interesting journey into the weird world of electrical connectors.
Eee, there's always one . Fair point though! The thing is that the 'creatives' who have asked me to make the prop don't really have a clear idea of what they actually want yet. I'll come up with something, they'll say 'Great, but could you change the place where you pat it to make the head nod'. It's an iterative process. So I'm trying to make my design as modular as possible. Hence the desire for connectors rather than soldering.
Dave - thanks for the link to Powerpole connectors. They might well be useful for something else, but probably overkill for this project.
Thanks for replies - all very helpful. I should have been more explicit perhaps - what I'm looking for is the in line type of connector pointed to by the red arrow. The board in the pic is the 'brain' of a toy pony - the various wires bring in signals from sensors on the toy's body and actuate motors which move the head etc. My task is to remount the sensors and motors in a much bigger frame for a theatrical prop, so I need to extent the wires.
Following the links it looks like JST connectors are intended only for PCB headers rather than in - line? It looks like automotive connectors are the things I want. I can get a box of 40 assorted from Amazon for a tenner - probably pretty flimsy compared to the more expensive connectors suggested in some replies, but will do the job for what I want I daresay. The thing is powered by six D batteries, so max 9V and not much current I guess.
Thanks again, Robin.
I have a project which would be easier if I could use in line connectors like this:
I've tried various search terms, but failed to find them so far. Ideally I'd like single, two, three and four way connectors which can be connected to the wires without any more specialised equipment than a crimping tool or soldering iron.
Can anyone help?
|Thread: Pesky Pixels|
It's a global preference within a user account on your computer - if I look at my wife's email (same account; different email name) when I am logged on as me I see my preferences, if I were to log in as her on our local computer I would see hers because Thunderbird would look at a different configuration file in her filespace. I hope! Local Thunderbird settings just filter the content according to our instructions and have little influence on what the email provider sends down the wire.
Edited By Robin Graham on 14/02/2022 02:59:23
Edited By Robin Graham on 14/02/2022 03:02:20
Michael - thanks for the link to digitalmarketer. Interesting reading. But you've set me off on a new quest now - I had thought that the phrase 'know thine enemy' must be biblical in origin, but it seems that goes back to ~500 BC in the Art of War by Sun Tzu. There must be a digitised translation on the internet somewhere...
Edited By Robin Graham on 12/02/2022 00:50:47
Ah, thanks, I'll look. I'm so old that I remember ELM - the recursive Pine Is Not Elm isn't true apparently. I'm such a dinosaur that I still use vi for text editing!
I had an email from a bank the other day telling me that there was an important message in my account inbox. For some reason I read the email more attentively than I usually do (their messages are rarely if ever actually important) and noticed that somewhere in the small print they confessed to embedding an invisible pixel in the email. So they could check that I'd opened it apparently. I was a bit foxed about how a pixel could do that, but after a bit of thought I realised that if the 'null' pixel had to be downloaded from their server, it would tell them that I'd opened the email and probably when and from what IP address.
Well, OK, I suppose that if they need legal proof that I'd received their communication it's fair enough. Though I doubt it would stand up in court - sometimes I come home and find the dog watching inappropriate content on the TV. She just likes to snuggle up with the remote. Maybe she gets to the computer as well....
It all seems a bit sneaky though. Why make the pixels invisible unless you're intending to deceive? I think I may go back to PINE.
Edited By Robin Graham on 11/02/2022 01:16:57
Edited By Robin Graham on 11/02/2022 01:18:14
|Thread: Yet another knurling question.|
A (possibly final) update on progress with this.
First, thanks for your contribution Neil and apologies for not responding. This project started because a fellow forum member was looking for continuous knurled bar to slice up in much the same way as you have done.Your work looks enviably good.
After some experimentation I managed to make this (at least sort-of) work with the cheapo floppy scissor tool:
Those are details of 250mm lengths.
The pictures are not flattering to either my machining or photography skills - the bars look better in real life - but they do show that the diamond knurls are reasonably crisp and even, and the straight ones are - well, at least straight. And not ragged as in the in photo in my opening post.
I think the main reasons for the improvement were using flood coolant (there were visible amounts of swarf carried away) and not attempting full depth in a single pass. I ended up putting 'a bit of a cut' on at the tailstock end at 200rpm, traversing to the headstock at 0.2mm/rev, then putting 'a bit more cut' on on and reversing to the tailstock. Quite possibly I could have gone faster, but it was working and I'm not on piecework.
The devil in the detail is 'a bit of a cut' perhaps - I don't know what that means, and neither do you .Just what felt right after many trials. Which isn't helpful!
Anyhow, thanks to all for advice.
One day I shall make a Marlco type tool perhaps and see how that goes. I do like a crisp knurl I have to admit.
Edited By Robin Graham on 08/02/2022 00:46:49
Edited By Robin Graham on 08/02/2022 00:57:49
|Thread: Bargain workshop stand.|
I was browsing for rubber tubing (to connect suds pump with through coolant tooling) tonight and ran across The Lab Warehouse. I had nose about their site of course and came across this:
You can get one of these for a mere £812.40. Just thought I should give a heads up on this excellent deal.
Seriously though, would anyone pay that much? I suppose some must, or they wouldn't be selling them.
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