Electronics in retro fit of CNC control on X3 Mill

[steve kendall 1Participant @stevekendall1]

I have been reading the excellent article written by Dick Stephen in Dec 2004 to March 2005 MEW about retro fitting CNC control to the X3 mill.  As I am far more comfortable with the mechanical side of the project, I intend to build the electonics side of the project first .  I am looking at the manual control box at the moment, the diagram fig. 9 on page 33 of Feb/Mar issue shows one 7490 IC, but the parts list and photo 25 shows two of them.  I assume that due to my lack of expertise in electronics I am missing something obvious.  Can anyone help?

 

Steve

[steve kendall 1Participant @stevekendall1]

Circuit diagram for manual control box Dick Stephen’s Article 2005

[Anonymous]

Ah well, I’ve failed, at a quick glance I don’t understand it either! The parts list and circuit diagram certainly don’t seem to match. It looks like there is some circuitry missing.

 

Personally I wouldn’t design the circuit as it stands, but I expect it will work after a fashion.

 

Regards,

 

Andrew

[Martin WParticipant @martinw]

Steve

 

While I have not looked at the article you refer to I believe that the 74 series ICs and their CMOS HC replacements are obsolescent or obsolete now. Before committing to anything I would advise that you check that you can still get the listed components plus a few for spares should anything go wrong . I have had a quick look at Maplin and CPC and they only stock very limited ranges of these ICs.

 

Cheers

 

 

Martin

 

ps.

 

RS Components & Farnell still stock SN74LS90 ICs so they are still available .

Edited By Martin W on 26/10/2010 18:14:52

Edited By Martin W on 26/10/2010 18:19:52

[Anonymous]

I agree that the original 74 series logic is pretty much obsolete, as is the HCT series, and to a large extent the LS series. The L and F series never really took off. However, the HC series is still readily available. Maplin and CPC are not really electronic distributors. Try Farnell and RS, or in the USA, Mouser and Digikey.

 

Regards,

 

Andrew

Edited By Andrew Johnston on 26/10/2010 18:53:09

[Billy MillsParticipant @billymills]

Think that the other IC  provides  gates. The basic idea of the controller is very simple, there is a rotary encoder which generates pulses when turned, the 7490 decade counter is used to reduce the pulse rate from the encoder. So it is a bit like putting a reduction gear between the knob and encoder.

 

Any division will aid slow adjustment, 4,8,16,32 are all very easy and cheap to arrange. But the whole thing needs redesign to bring it up to date. Tried looking for the article on the Arc site but the PDF’s don’t seem to want to open.

regards,Alan.

[John Stevenson 1Participant @johnstevenson1]

Dicks CNC conversion was a bit of a mis match.

he wanted a rotary jog wheel but he was using Desk CNc which can’t handle one so he fitted DRO’s to the machine so he knew where he was and could manually feed thar information back into Desk CNC.

 

If you use Mach3 you can jog with a jog shuttle and still keep track of where you are.

 

 

None of the fancy electronics is needed.

 

John S.

[Anonymous]

I’ll second that; I have a jog shuttle running with a customised version of Mach3. Marvellous bit of kit for moving the axes manually.

 

Regards,

 

Andrew

[Martin WParticipant @martinw]

Hi Andrew

 

While I tend to agree with you re Maplin and CPC they do provide easy access for the occasional user. Farnell are quite easy to deal with but if I remember correctly you need to open a account before you can use RS Components, or have they changed their procedures?

 

This year CPC have massively increased their stocking of electronic components  and that is why I tried them before Farnell.

 

Cheers

 

 

Martin

Edited By Martin W on 26/10/2010 23:18:07

[Peter G. ShawParticipant @peterg-shaw75338]

RS Components have indeed changed their procedures. Yes you still need to register, but you no longer need the trade references etc, and it can be done online – http://www.rswww.com – as can all the ordering and payment.

 

The trouble is that as ever, they are expensive, but their delivery is quite good, first class even. And they do have lots of stuff I certainly have difficulty finding elsewhere.

But a tale!

 

About 40 or so years ago I worked in a department which had access to the RS catalogue, and to order components we obtained an order code from our finance people, rang up RS, gave the order and the code, and lo and behold the items duly arrived. The invoice was usually sent to us a few days later, and we passed it on to the finance people for payment.

We also used to regularly receive visits from their salesman, so one day, wanting some stuff,  I asked him how I could get it. His reply was to send a cheque with a written order and use our works address.  Fair enough, this worked.

So one day I tried a variation. Wanting some tools for myself, I made up an unofficial code, my home ‘phone number actually, placed the order, the tools arrived and I sat back waiting for the invoice, my intention being to send off a personal cheque. Fortunately, I had primed my colleagues about what I was doing, because one of them received an anguished cry from finance saying that they had received this invoice from RS complete with a code that they did not recognise. My colleague quickly offered to sort it out for them if they would send him the invoice. The invoice arrived and I duly paid.

I still have, and regularly use those tools.

 

Regards,

 

Peter G. Shaw

 

[David Clark 13Participant @davidclark13]

Hi There

I regularly order from the radiospares website.

I had no trouble arranging an account and they usually send out even small orders post free.

Ihave on occaision paid for more expensive items over two months.

regards David

 

Edited By David Clark 1 on 27/10/2010 11:17:20

[Anonymous]

Ah, Peter has beaten me to it! That’s what comes of being out in the workshop this morning instead of mucking about on the computer.

 

It seems that a lot of electronics distributors are going for online ordering. I have a trade account at Farnell, but even with that, if you order over the ‘phone there’s a minimum order charge of, I think £20, but there’s no minimum for online ordering.  As Peter says, there is no longer any need to have a trade account to order from RS. Just register and order online via a credit card, which is what I do. I don’t use RS much, too expensive, but sometimes they have what you need when nobody else does, it’s normally in stock and next day delivery is standard. For semiconductors I often order online direct from the manufacturer.

 

I have had a few run-ins with RS over the years. The most embarrassing one was over accounting. One of companies I work for has an RS trade account. I sometimes ordered on this trade account, but had the items delivered to home, as that was where I needed them. Conversely I sometimes ordered online using my personal login and credit card and had them delivered to the company, as that was where I would be on delivery day. For some bizzare reason RS got their knickers in a twist so that when I ordered online with delivery to home, my colleague’s company got the invoice! RS accounting simply didn’t understand the problem, and the IT department said they couldn’t change anything anyway. I only got it sorted out when I wrote to the MD and suggested he sack his head of IT.

 

Martin:

 

Interesting that CPC are now stocking components. As I’m sure you know Farnell and CPC are part of the same group, so on the surface it would appear that CPC stocking components would conflict with Farnell. Presumably the marketing people assume that the Farnell and CPC demographics are different.

 

When Maplin first started back in the 70’s I used them quite a lot (every week!) but they gradually seemed to move towards kits, computers and audio/visual stuff, so I went elsewhere. I pretty much exclusively use surface mount components now, which tends towards using the larger commercial distributors.

 

However, all this is somewhat academic, as there is a worldwide shortage of components at the moment, even on the ‘grey’ market. You wouldn’t believe the hassle we’ve had trying to get boards assembled commercially, aaaaaaaaaaaargh!

 

Regards,

 

Andrew

[Billy MillsParticipant @billymills]

CPC have always stocked active and passive parts, their origins – as with RS- were in the Radio/TV servicing trade. They have very good prices on connectors and made up leads, CAT 5 leads are a fantastic bargan from them as are very many other bits. Use them a lot.

 

Would not argue with John S about the origins of the controller however  Steve is looking for a simple way of testing his work so the rotary encoder is a simple way of getting there. Decent encoders are a bit pricy but you could rig up a trial with an old scroll wheel mouse and a D type flip flop.

Regards,

Alan.

[Billy MillsParticipant @billymills]

Had a quick look at the part 3 article on Arc’s site. There were two 7490 decade counters in the original design which was pictured in the article. You could use one of the switches ( that were not in the circuit) to get 1, 10 or 100 to 1 reduction in the jog rate. Those are the two larger IC’s on veroboard.The 100:1 was found to be not very useful so was left out.

 

There is another, smaller IC  ( LS7184)  which is an interfacing device, it converts the two quadriture signals ( A & B) from the encoder into clock and direction signals. This IC also multiplies the clock rate by four. Most serious of all is that the divider will never work at all. The diagram shows the clock is not connected to the divider ( pin1 BD in) at all!

 

Regards

Alan

Edited By Alan Gray 1 on 28/10/2010 15:13:25

[Sub MandrelParticipant @submandrel]

> I regularly order from the radiospares website.

 

Wow David, not many people who still call them that. When I was a boy my Dad had a Radiospares account and I used to beg for items to be included out of my pocket money.

 

In those days the catalogue was about 1/4″ thick, and I used to eagerly await the old one when dad got a new edition.

 

I still have some of the data sheets from those days.

 

Neil

[john swift 1Participant @johnswift1]

Hi Neil ,

I remember the old RadioSpares logo  – a bit like the new BT one

 

do you remember the ” DORAM”  or  “ELECTROMAIL”  catalogues

 

 I still think of BT as part of the “post office”

 

  John

 

[David Clark 13Participant @davidclark13]

Hi There

Always called them that.

Catalogues are now over an inch thick and I think they are at least 6 of them.

regards David

 

[GT390Participant @gt390]

Posted by steve kendall 1 on 26/10/2010 17:23:46:

I have been reading the excellent article written by Dick Stephen in Dec 2004 to March 2005 MEW about retro fitting CNC control to the X3 mill. As I am far more comfortable with the mechanical side of the project, I intend to build the electonics side of the project first . I am looking at the manual control box at the moment, the diagram fig. 9 on page 33 of Feb/Mar issue shows one 7490 IC, but the parts list and photo 25 shows two of them. I assume that due to my lack of expertise in electronics I am missing something obvious. Can anyone help?

 

Steve

Edited By GT390 on 29/11/2011 23:18:29

Edited By GT390 on 29/11/2011 23:18:56

Edited By GT390 on 29/11/2011 23:21:40

[GT390Participant @gt390]

Please ignore my post above, forgot that all sorts of wacky things happen when I access the forum using Internet Explorer, unfortunately anytime I wish to post I need to use Firefox, even though I am not using 64 bit windows,

 

anyway, what I was trying to say above :

I have been considering retrofitting one of my Hurco mills to a modern PC based controller for a couple of years now, and have been doing some research, would it not be fair to say that any retrofit performed in 2004 would be twice the work and half the performance of some of the kits and components available today, some of which are pretty much “plug and play” , now I cannot be too critical as I must confess I have not read the article in question, but I have seen some big improvements in the harware and software that has became available over the last couple of years, maybe you may already know of these few sites, but incase you have not take a look at :

 

http://www.cnc4pc.com

http://www.pmdx.com

http://www.diycnc.co.uk/

 

hope this may be of help

 

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