Union Jubilee Clutch.

[Refugee]

What load are you switching with the relay?
The speed controller is almost certainly designed to feed solid state relays. These are both simple to make and not awfully expensive to buy.

[Retired]

Hi,

Good question and thanks for asking Refugee.

I need to check but I think the load is extremely small it just being a signal cable which I believe is on 10VDC.

Its only the start/stop I need the relay for in order to allow the original control buttons to be used; when I was using this VFD set up on the Jubilee I had installed a latching push button for the start/stop control but now I want to use separate original Graduate start/stop buttons.

The new relays arrived today so I can play around a bit tomorrow and report back; the relays were very cheap so I bought two; one will be a spare. These are the relays I bought;

http://www.ebay.co.uk/itm/400380625226?s...K:MEWNX:IT&_trksid=p3984.m1439.l2649

As usual I'm busy and today I've been doing more work to convert the garage into my workshop; I've now found the bandsaw a permanent home after installing the drawer unit I had carried down from the workshop and I've been painting the walls; the conversion seems never ending but then I've just spent three weeks restoring the Graduate; it's all coming together slowly and I'm enjoying myself. The benches are still cluttered and I'd like to fully restore the bandsaw finishing it with the cream white enamel which looks so good.

Kind regards, Col.

   

[Refugee]

Are the 10 volt supply and the start stop signals all on a single terminal strip?
It may well be that the signal just goes to an opto isolator and that the switch could be a silicon transistor latch that comes as an internal part of the switch that would be supplied as an extra for the controller.
The 10 volts in in line with the remote switches having a basic 1980s logic chip in them and nothing else.
They just drive an LED hidden in a bit of black plastic that shines across a clear insulator inside the controller.
On a Google search just type "4013 data sheet", or "4027 data sheet" then look for the modern static resistant types with HEF starts and not the obsolete CD one as they are NLA.
Also try the numbers followed by start stop switch and see if there are any others who have already built these units.

[Radio Fixer]

I haven't been following the thread totally but just wanted to say how smart the lathe looks Colin. Boy! its almost too good to use but remember the first scratch is the worse scratch. Going to be a real Pro shop when done.

Gary

[Retired]

Hi,

Many thanks Refugee for taking the time and trouble to add the information. Unfortunately I'm not into electronics only knowing the very basics and I tend to learn on a need to know basis. I knew what I wanted to achieve in relation to very simple circuits and this could be sorted out with a cheap relay.

I'm indebted to Big Al for kindly sending me details of the correct relay to buy and for the schematic; thanks Alan. Over the last couple of days the big key in my back has been wound to maximum as I made all the silly mistakes first before getting it right. This morning I spent ages trying to get a continuity reading through the new start/stop wiring without luck; I suspected a faulty switch but on two different circuits? After dinner I took a big PSU into the garage and using this with a 9V lamp found both circuits to be fully working; so much for using my DMM? Nothing at all went right this morning and into this afternoon; I had turned on the heating and once warmed up turned it off only for the cold to creep up on me so by dinner time I was perished. I dropped a small screw and still haven't found it even though I spent ages on my hands and knees; and so it went on.

In the end I disconnected the relay wiring and started from scratch so finally it gave in and now the Graduate is fully working through it's original start/stop buttons with new forward/reverse and variable speed; what a lovely lathe and by doing this restoration/upgrade myself I've now got a top quality lathe at a very good price. I've also had the pleasure of doing the work whilst learning something new.

I've added an 11W lamp as a power on reminder because it would be so easy to leave the garage forgetting to switch the VFD off.

Thanks for your compliment Gary; yes it's a shame to use the Graduate now in case I scratch it but hopefully over the next few months I can settle down to some woodturning; I also plan to restore my newly purchased bandsaw so eventually will add the story.

I've previously mentioned the variable speed pot only does about quarter sweep from off to full speed and this is common as I've read others have the same problem but without finding a solution. I emailed Huanyang but they haven't replied. If I can't sort this out electrically then I'll jolly well use my mechanical engineering experience and add a pair of reduction gears to the pot and I've already bought an assortment of plastic gears through eBay which will arrive shortly. I'll not be beaten and I've no intention of wasting hours wading through around 250 parameters on the VFD trying to get lucky?

Kind regards, Col.

           

[Yorkie]

The VFD control sounds odd Colin - you'd have thought that it should/would be designed so as to give linear control over 270 degrees of rotation from off to full on. I guess that a ten turn pot (if one with the right value and wattage was available), would give more breadth of control. (I wonder whether the pot in linear, log, or inverse log?).

Hopefully you'll get a satisfactory reply from the maker's.

The graduate is an amazing transformation, both appearance wise and mechaically!

[Refugee]

The easy method to get the speed pot to cover the full range would be to run the machine up to full speed and then stop it with the switch and measure the actual value from the stop point to where the wiper is. Buy a pot of the closest value and a range of resistors close to the value from maximum speed to maximum rotation of the pot. Then select a resistor that gives maximum speed as close to full rotation as you can.
The tolerance of the total value of the pot will most likely be 20% so a little bit of variation in the value will not damage the controller.

[Radio Fixer]

Blor Edwards is the place for pots if you go this way.

Gary

[Retired]

Hi,

Thanks David for your compliment. Yes it's very strange that Huanyang make these excellent VFD's but then in the manual state a 10K Linear pot must be used; I did try a 5K pot making not a bit of difference. I'm a novice though with these VFD's and I feel as I gain more experience I could possibly locate the correct parameter to adjust allowing the pot to give full sweep but it all takes so much time. The VFD is remarkable value for money though and I'm delighted with mine so far.

Great idea Refugee. A few years ago my new cheap vac packed up and it would have cost more in postage to return it than throw the vac away. Out of curiosity I stripped the vac to find the speed control slider pot had expired due to ingress of dirt; I did as you suggest here and removed the slider pot replacing it with a fixed resistor giving fixed speed and the vac has been perfect ever since. I'm very wary though regarding playing around with the VFD adding remote controls; it took a lot of web browsing but eventually I installed the remote controls I needed and now only the pot could do with some fine tuning; I'm sure as David suggests a multi-turn pot would allow very fine speed adjustment but I really want to control the speed with a single turn of the pot. I've already bought the plastic gears and can experiment a bit once they arrive; I can turn this into a small project as I'll find it interesting.

I could easily do as you suggest Refugee and measure the actual pot resistance between off and full speed and I'm sure this would normally work by replacing the 10K pot with one of the new rating but I don't know what effect this would have upon the VFD control circuit; I feel the 10K pot is there for a reason; I did take a deep breath and try a 5K pot but without success so it's possible just a parameter requires adjusting and knowing how many hours I put in sorting the remote controls out I decided to experiment with reduction gearing which I understand removing the risk of damage? I do however very much appreciate your help and suggestions because I like to learn from people such as you are much more knowledgeable on things electronic.

Thanks Gary; I've had a quick look at the Blor Edwards website and what a selection of pots they have to the point of making bespoke pots; if you recall Gary I did some experimenting a few years ago making my own pots but for the more difficult AVO VCM saw-tooth pot I couldn't find a supplier of small quantities of resistance wire? I was successful though in making a bespoke pot for a petrol tank unit for a vintage car.

I'm just so busy converting the garage into a workshop to spend too much time concentrating on the pot problem because the Graduate is working extremely well indeed; it's just me nit picking wanting it to be perfect after all the TLC I've just expended on its rebuild over the last three weeks.

I'll have a look at the Blor Edwards website in more detail a bit later but in the meantime any ideas where I can buy a single turn heavy duty 10K Linear pot; the one I'm using is cheap and makes me wonder how long it will last before it expires?

Kind regards, Col.

[Refugee]

If the range was the same with the 5k pot it shows that the value of the pot is not critical.
I would fit the 5k pot and replace the unused part of the 10k pot track with a 4k7 resistor.
Just hide the resistor in a bit of heat shrink and the controller will be none the wiser.
The total value will then remain close enough to 10k that it will work just fine.