Here is a list of all the postings Peter Bell has made in our forums. Click on a thread name to jump to the thread.
|Thread: Arduino Pendulum Clock Design - Comments Welcome|
Reading the post from Marcus made me realise where I got the inspiration to try an energising coil without a core, it was from reading the Dick Stephen article and was a breakthrough moment for me.
I also considered that the magnetic field would be a srange shape without a core to concentrate so I used iron filings on a sheet of paper above the coil and got a result with a dead position in the middle so I thought I had the centre of the bobbin was too large, however it worked fine on my simple clock pushing the magnet out of the way once started until the detected pulse width stopped over swinging..
I considered that the swing was going to be eliptical, my question is how can the circular error of the pendulum be measured, apologies if it's already been covered somewhere? Did wonder about a laser mounted on the swinging pendulum bob shining onto a card or something?
My high friction clock is impulsed for 80ms but will run with a pulse width of 40ms. The magnetic sensor looks for a pulse length of 20ms before switching off and it can only manage a couple of swings before its re-energized .
If I switch off completely it takes 10 secs before it stops incrementing the count wheel and approx 60 secs before the pendulum is stationary. It takes a tiny push to get it going and around 30 secs to build up sufficiently before it is up to full swing and limiting.
Its quite nice to stop the clock and see it build up again with the led in series with the coil flashing then stop and bounce on/off when its limiting!
I have another more conventional experimental pendulum running on a similar impulse system but pre arduino which uses a pulse on time of around 5ms but its not driving anything.
Really interesting to follow this thread. I made the John Wilding "Simple Electric Clock" in 1987 and soon found it to be very unreliable. It works on the Hipp principle and the contacts were forever going out of adjustment and needing cleaning. Adding some transistors to help the switching didnt help so it was forgotten for years.
Eventually replaced the Hipp arrangement with two magnetic sensors (optical sensors soon failed with dust?)and 555 timers to control the pulse and it worked but soon found that the soft iron core of the magnet was magnetising the swinging armature and eventually becoming unreliable and stopping, abandoned again!
Fast forward a few more years and I made an energising coil without an iron core (fine wire 2K ohms) and replaced the swinging armature with a 6mm neodymium disc magnet so that there was no interaction when swinging and unenergised..On the 555 it worked but was complicated. Discovered Picaxe micros and got a version working after learning some programming. Eventually moved onto Arduino and the latest version measures the pulse width with a magnetic sensor and stops energising the coil when a predetermined pulse width is reached. When its being energised by the Arduino the armature with magnet is pushed away.
Been going a few months now and think its the best I've managed to get it running. The pundulum is on knife edges and quite a bit of friction in the train which I've reduced. but could be improved on.
Not in the precision league I'm afraid that Dave's trying for but I'm pleased with the progress!
|Thread: VFD. XSY AT4 220v 1phase to 380v 3phase advice sort|
Not sure if its exactly the same as the one I looked inside but that only had the voltage doublers caps so I assumed they were also the smoothing caps.
It also had a small module to reduce the surge switch on when the cap were initially charging and the rail voltage was 660v dc..
|Thread: Arduino low power alternatives|
I'm with Dave on this one.
My first venture into microprocessors was with Picaxe. These worked well but it was a construct job every time changes needed to be made but I gained enough confidence to try Arduino. The nano with its ease of use by being a plug in with a bulit in reg and status led 's was a great step forward at least for me especially at the price.
So I would remove bits of a working nano to reduce consumption and intend doing this some time in the future rather than start from scratch unless I've got to!.
|Thread: garden tractor wheel lug nuts and studs|
Seen lots of instances like that where the stud winds out of the hub over the years and eventually becomes very "slack" in the hub.
Normal repair I've seen is a tack of weld on the stud to hub where the stud protrudes through the back of the hub or its peened over.
Often found that the fit of the stud in hub is too loose to be effective for loctite.
Edited By Peter Bell on 02/06/2020 09:10:32
|Thread: Measuring wear on a surface grinder|
I got a wartime Norton grinder (18" x 6" at the right price which by appearance I expected to be compleley worn out but it turned out the ways are lubricated by the hydraulic pump and were perfect.
I found the spindle had excessing play using a DTI which I corrected.
After that it was a case of measuring a ground piece and seeing the surface finish--whole new world of leaning for me!
Certainly looks decent, sure you will find it a very useful tool
|Thread: Fusion 360 CAM cost?|
My son has been some of his recent enforced spare time to continue the refurbishment of his Bridgeport mill. This has gone well and he has moved onto cad using Fusion 360 as a hobby user and made good progress after watching some of the excellent tutorials.
When he was attempting CAM to generate G code he got a message saying he would be charged for this service starting May.
Is this normal?
As a lot of others on the forum use 360 I wondered what else they use to generate G code? He has a licecensed copy Mach 3 he intends using.
|Thread: Ebay screen|
Yes that was the link which proved troublesome. The ebay screen (and others) had been like that for a few days but when I originally clicked the link it reminded me to post asking for advice. Another thing was I could not add the pic at the time of the original post but I could after I'd used CC cleaner so can only conclude I'd picked up something.
The link works fine for me now, tried "restart with add ons disabled" but it didnt cure the original problem, tried it again now and everything still works the same.
Fingers crossed, its solved!
Thanks for the advice.
Tried as suggested also various other fixes but no improvement. Noticed the the ebay prices sometimes appeared as $.
Ran CC Cleaner which found loads of trackers in spite of having tracking off in firefox and now seems to work fine!
I can also now add the pic which I couldnt do yesterday. Hopefully thats it.
When I go into ebay by following a link or just from the ebay home page my screen goes strange with over lapping text.
I uploaded a screenshot (jpg) to my album but I cannot add the pic to this posting although the ok button turns green when I select the pic from the album?
I assume I've done something wrong but cannot seem to find the setting to correct it---is it a browser problem---I'm on Firefox--can anyone guide me how to get back to normal?
|Thread: Inverter failure guidance|
Not sure about your drive but I've got an ABB ACH-550 (15kw) which has a backup battery in the display . Dont know where the start parameters are stored but its an easy job to replace the battery and it may just be the answer.
|Thread: 7 pin connector 240v?|
Yes decided that the "aviation" are a no go.
Looked at the Han option earlier but not familiar with them and a bit wary of so many options so I'll need to spend a bit more time on it later before I take the plunge.
Thought this would be easy!
Thanks everyone--bit of a minefield, no wonder I was puzzled!
I've also suffered the min Bulgin on hifi kit so rather avoid, the other Bulgin are a bit big. The CPC suggestion sounds good but the voltage is a bit low for a reasonable amount of pins. Dont really want to attempt dedicated crimping—also been there before!
Suspected the C091 was not suitable for 240v which is why I asked the question.
The application is to connect to the operating coils (240v) on 3 existing air solenoid valves. I want to connect these to relays inside a dedicated box which is housed inside a cabinet.
If I use (reasonably priced) connectors I’ll be able to proof test the box in the workshop as the equipment is in continuous use.
I want to use a small 7 pin plug and socket to carry around 100ma 240v ac each pin.
I have looked at the Amphenol C 091 series (T3476 001 etc, from RS) which appears to be rated at 240v ac and 5a.
However I seem to remember some "communications" on this or a similar subject recently on this forum but cannot remember where and cannot find it!
Can anyone point me to the thread or suggest something suitable without breaking the bank?
|Thread: Solar panel surprise|
I completly missed the boat with all the better tarifs due to being indecisive!
Installing now, does solar still repesent a decent investment, and has anyone installed panels recently?
|Thread: Windows 7 support ends|
Been reading this thread with interest poised to go to W10 from W7 but just received an update for my W7 as I shut down earlier. Rather strange but all seems to be working ok after the installation. Odd on the day support ends. Anyone else had that happen?
Do I expect to see W10 installed and working or something worse when I switch on tomorrow ?
|Thread: Tool boat sizes?|
Hi Bill & John,
Thanks for your help. It looks like it is bigger than an S4 (147mm) as its 160mm long but the tool appature is right at 38mm.
The S5 looks like it has a tool appature of 44mm from the lathes data.
None of the data found so far gives the "V" locating dimentions that go onto the tool post.
Wondered if it was an S4 with a slightly longer body? Wondered if anyone had an S4 to measure the fitting dimention?
Hello, These were bought a few years ago at stationary engine rally. However they turned out to be bigger than the ones used I use on my lathe, they looked the same at the time!
Can anyone suggest what size or type they are?
|Thread: DCGT polished inserts|
Dont know about DCGT but I bought some DCMT0702 EM YB205 which appear similar and are very good on most things including brass and steel and cost £3.28 for 10 in P&P.
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.