213 forum posts
Ian P - “I have a question about the actual 'O' ring you used. The majority of seals easily available are black in colour. I have seed silicone rings which look red/brown and some green 'O' rings, what type are the ones in the picture and who stocks them?”
Ian... if my memory serves me well - the red or orange ‘O’ rings are high temp silicon, the green ones are Viton (we used these on multi fuel systems in engine test bed applications) and the standard black ‘O’ rings are Nitrile. (I’ve noticed these are uv resistant)
There is an ‘O’ ring specialist in Aldershot, Hampshire under the name Mantek **LINK** unfortunately they have dispensed with their trade sales counter so it’s technical help only by ‘phone. The type should be easily obtainable. I hope that helps.
‘Usual disclaimer - no affiliation with firm but I’ve bought from these before.
|Ian P||25/04/2019 09:00:55|
2243 forum posts
Thanks John, I will try the supplier you suggest, most of the stockists I have tried will supply silicone rings but usually to special order withe large minimum quantities.
|duncan webster||25/04/2019 09:46:16|
2262 forum posts
All the viton ones I've ever bought were black, not quite as shiny as nitrile
213 forum posts
correction - I should have said the nitrile ‘O’ rings are not UV resistant. 😳 (Dyslexic)
Duncan - thanks for that. I’ll try to put that into my memory 👍
|Howard Lewis||25/04/2019 13:18:57|
|2439 forum posts|
It may be that the red silicon rubber seals have a greater temperture range. We used red silicon rubber lipseals on engines that were going to used in temperatures of the order of -40C, where the black Nitrile seals would be too stiff to seal properly (Their limit seemed to be around -25 / -30C )
|David George 1||27/04/2019 09:40:09|
965 forum posts
Hi all I bought a Newing-hall engraver cutter grinder a while ago for sharpening carbide tools with a diamond type wheel. I have only just got round to making a tool support as the original tool support is only for round cutters and here is a few pictures of my effort.
|284 forum posts|
Finally got around to silver-soldering some steel components of my built-up coupling rods. Only chose this method due to lack of ready access to a milling machine to mill from solid.
Surprised how easy it was once I had sufficient heat. Ended up putting too much solder in some areas as it flashed through the gaps very quickly once melted so I was a bit unsure of whether there was enough to make a solid joint, hence added a bit more 'for good measure'. Turns out I shouldn't have.
Despite all advice about needing absolute cleanliness, managed to solder in solid some temporary spacers made from black mild steel that had only had the mill scale cleaned off with vinegar and were otherwise untouched. Seems like Tenacity flux works pretty well even on dirty steel.
Now to clean up, drill and ream holes for bushes and fit to loco. Will post some photos when they look decent enough.
|Nigel Graham 2||27/04/2019 22:35:06|
|434 forum posts|
Today? Well, had a rest from engineering by going caving! I did enter the workshop on my return home, but only to collect the bird-seed and top up the feeder: the sparrows are eating me out of house and home!
Yesterday though... a few more hours making the umpteenth aluminium or PVC item to fit the DRO to the Myford milling-machine, trying to think how and where the vertical magnetic strip will go, so what I am building to carry the cross (Y) feed sensor won't prove to be in its way.
I used the now-installed long-travel (X) read-out for two parts, only to find they don't go together quite as neatly as hoped because I'd unwittingly mirror-imaged the datum ends!
|John Reese||28/04/2019 01:02:35|
|797 forum posts|
I have been trying to figure out why smoke is coming out of the motor control of my Taft Pierce surface grinder. I checked with an ohmmeter and found infinite resistance from all 3 phases to ground. More investigation tomorrow.
|Simon Williams 3||28/04/2019 12:03:27|
|426 forum posts|
It wasn't today, it was yesterday, but this is an object lesson in leaving well alone.
I bought a bandsaw from my local secondhand shop, did the insulation test and earth continuity, plugged it in, happy days.
The main lead had pulled through its cable gland into the motor terminal box, so yesterday I thought I'd while away 15 minutes putting that right. Simple enough.
Until I took the cover off the terminal box, and realised that the black bits in the bottom were broken insulation off the motor leads. Oh dear.
Can't leave that alone, so here's what I found when I took the end cover off the motor:
Not the best photo ever, sorry about that. The green lead RHS of picture is one of the main winding leads, the two once-upon-a-time white ones are the starter winding on a 6 pole single phase capacitor run motor of about 3/4 HP. These wires are the original tails connected to the motor windings, and look as though they have been overheated though I can't explain why there is no evidence of damage to the windings themselves, and no "burnt" smell. The insulation is brittle and cooked, and the wire itself is tarnished and oxidised.
I cut the damage out, grafted some PTFE insulated wire in with heat shrink sleeving and threw it all back together. Not the best job ever, but better than it was.
I could have made a better job if I knew how to withdraw the stator lamination stack from the motor outer housing. Any clues anyone? The only thing I can find on the internet assumes the windings are already toast, and you can pull the whole thing to pieces by brutality. In my case there seemed to be nothing wrong with the windings and I'm reluctant to get it rewound when it still works.
So it runs, takes a sensible looking load current, insulation at 500V is 85 megohms. I've put it back together and it'll do.
Rgds to all
|Neil Wyatt||28/04/2019 14:12:58|
16738 forum posts
Etching a couple of PCBs. The ancient bit of board I found took ages to develop, so I gave the second one a double length dose of UV, which worked OK. Both are look OK though.
|John Hinkley||01/05/2019 16:05:38|
769 forum posts
Went to pick up a pantograph engraver the other day and today I have been running an oily rag over it, prior to trying it out. Unfortunately, I've found a couple of sheared 2BA countersunk screws which need replacing. I'm all-metric as a rule, so I've had to order some from the internet. I hope that they will arrive before the weekend. Until then, I'll continue to work on the operating instructions. Having failed to find a manual of any sort on the internet, I was delighted to discover when I picked it up, that it was complete with operating instructions and some publicity material, too. The instructions were dated 1969 and were typed on what must surely be a manual typewriter. I have nearly finished re-writing them in Word, incorporating all the other material with it. This has meant redrawing some of the illustrations, so it's taken quite a while. When it's finished, I'll have it in .doc and .pdf format, so if anyone wants a copy, PM me and I'll send it to you. Might take a week to get it completed, though!
Here's what it looks like, squeezed into the only remaining bit of space left in the garage:
|David Standing 1||01/05/2019 16:47:56|
|1280 forum posts|
Lucky man, if only my life were that simple!
I have projects/machines that are:
Enfield small arms standard
And probably some more I have forgotten!
|John Hinkley||01/05/2019 17:08:26|
769 forum posts
I'd probably have more of an eclectic mix, too, if I hadn't had to metricate when we retired to France. It's bad enough trying to source small metric fasteners there, let alone stuff from the Empire!
Still, back in Blighty now and the world is my lobster, thanks to the internet and fast broadband.
4787 forum posts
Snap!. The DD is a nice little machine John. I found the on off switch that operates as you lower the arm kind of finicky so took it out of circuit. Also check your brushes. I was lucky and found my collection of 'useful things' had one the right size. If you get sparking at the brushes it might also be they are sticking on the holder.
|John Hinkley||03/05/2019 10:06:49|
769 forum posts
"These are to assist in positioning the workpiece and copy holders relative to each other."
Not very helpful! Send me a PM with your email address and I'll pop a copy into the ether for you. Let me know whether you want a Word document or pdf. (They are 9.5Mb and 6.1Mb respectively.)
|338 forum posts|
Fabricated a novel locking bar system for a pair of inward opening external doors on an 18th century stable block. Central pivot point, offset rather than central so the bar swings down under it's own weight when unlocked. Simple metal pin retaining mech to avoid use of keys. It's on the inside of the building so secures the door as you leave from a smaller personnel door.
Good fun figuring it out and turning the pivot etc.
|Boiler Bri||04/05/2019 07:22:17|
810 forum posts
More what i am going to do. Its the victorian extravaganza in Llandudno this weekend and i am off to run my engine on the west shore track 🤗🤗🤗🤗🚂🚂🚂🚂
|Boiler Bri||04/05/2019 18:50:33|
810 forum posts
Well i had a great time at west shore. I ran for 2-1/2 hours pulling passengers and then retired with injector problems. I also need to look at the axle pump as this does not put enough water in the boiler. Trouble is you can not see the rod gland when your running to see it water is being lost there.
All in a days running.
|Neil Wyatt||04/05/2019 21:29:32|
16738 forum posts
Sounds like a good day.
Please login to post a reply.
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.