Chinese tacho – beware

[Former MemberParticipant @formermember32069]

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[SillyOldDufferModerator @sillyoldduffer]

Posted by Barrie Lever on 21/06/2019 11:43:56:

Posted by Cabinet Enforcer on 21/06/2019 11:13:18:

Posted by Neil Wyatt on 20/06/2019 23:44:06:

Posted by Barrie Lever on 20/06/2019 16:25:59:

You are a wise and learned man, can you name me 5 Chinese brand names in mainstream retail? No meaning or agenda in the question.

Interesting question…

Lenovo and Huawei for a start.

Neil

Add Pirelli to that list. Xiaomi are not yet that big in western retail, …

I have never heard of those three brands,…

Barrie

Where have you been Barrie? Huawei are the largest Telecommunications manufacturing company in the world, in the news recently not because they make cheap crap, but because of security concerns their kit contains Chinese government sponsored backdoors. In the US President Trump is dead against buying Huawai infrastructure, in the UK Mrs May controversially agreed the UK would.

Here's the thing; Huawai aren't just making cheap copies, they are currently in advance of Western technology in this market. (4G & 5G)

Personally, I distrust brand-names. They're just labels, pawns in the hands of whoever owns them which could be anybody. They don't guarantee quality, value for money, country of manufacture, or cultural identity. Brands rise and fall like empires. Rolls Royce cars are nothing to do with Rolls Royce aviation. Dormer drills aren't made in Sheffield, and vacuum cleaners need not be Hoovers. Pens aren't filled with Stephen's Ink. etc etc.

Nice to think spending money on expensive brand-names saves trouble, but it might not be true. You can't generalise safely. It's always been the case: 'caveat emptor' said the Romans, and I expect cave-men were sold rubbish too.

Due to globalisation the best place in the world for industry is wherever it happens to be cheapest. At present, the Far East is booming. It isn't permanent.

Dave

[Former MemberParticipant @formermember32069]

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[Cabinet EnforcerParticipant @cabinetenforcer]

Posted by Barrie Lever on 21/06/2019 13:45:48

Sure I have heard of Huawei, it was Xiaomi, Haier and Hisense that I had not heard of.

All available in your local branch of Currys, under their own brand name.

Xiaomi is now the biggest smartphone brand in India, and 4th biggest worldwide, Oppo another Chinese brand you probably don't know is 5th biggest worldwide. You might not have noticed but plenty of people have.

[Cabinet EnforcerParticipant @cabinetenforcer]

Just to keep the thread vaguely on track, I have cheap tacho units on my lathe and mill, they take a second or two to settle, they could certainly be more responsive.

They have not been slow enough to motivate me into picking up the Sharpie and marking out 250rpm intervals around the knob, which would be sufficient I would think?

[Former MemberParticipant @formermember32069]

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[JasonBModerator @jasonb]

Posted by Barrie Lever on 21/06/2019 17:15:21:

I must be running around in a bubble not noticing these Chinese brand names, but I am not likely to if they have a Curry's badge stuck on them, silly me !!

" All available in your local branch of Currys, under their own brand name."

Hardly hiding behind a label.

[duncan webster 1Participant @duncanwebster1]

Posted by NZreg on 21/06/2019 00:02:03:

Take a look at this **LINK**

I have used two of these, the first on my Optimum lathe, laterly have one fitted to my S7.

Paired with a VFD its something I would not want to be without.

The S7 reads the teeth on the Bull gear and gives consistent readout.

Reg

I've no doubt it's very good, but there are a lot of bits compared with using Arduino

[Nick Clarke 3Participant @nickclarke3]

I am often surprised by the opinions expressed about cheap tooling. There has been cheap tooling for the last 150 years or so – called continental, made in Hong Kong, Jap rubbish (or similar!) and at present it is China getting the abuse thrown at it.

If cheap does the job then don't pay more! It is a sound engineering axiom that accuracy costs money, so don't demand more accuracy than necessary for the job.

If the collet is too far out send it back, if it is too expensive to do that (would you pay postage on a three quid collet?) then buy another – you are still in pocket and it usually works, particularly if you are making parts to fit together rather than absolute sizes.

Today many brand names, even those with a reputation going back years, have changed hands so often that the name is all that is left – Moore and Wright has had 5 owners as far as I can see as one example.

They say quality tools will last a lifetime – but as an amateur how many times might I want to use something in the ten to twenty years remining to me? – and as CADCAM means that accuracy can be maintained with little or no skilled input, many cheap tools today are close to being as good as more traditionally made ones in the past – not feeling as nice, and perhaps not as long lasting, but in general accurate enough to do a job at a price that means they can be afforded and used in place of a second choice lash up. So affordable milling machines, collets, oxy-propane and all the other things unheard of in an amateurs workshop 30 years ago or so are nearly universal today.

Please can we condemn and banish from our workshops bad tooling – but that doesn't mean banning cheap tools or Chinese tools or any other tools unless they truly are unfit for the purpose and circumstances they are going to be used in!

Nick

[Former MemberParticipant @formermember32069]

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[Former MemberParticipant @formermember32069]

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[Nick Clarke 3Participant @nickclarke3]

Posted by Barrie Lever on 21/06/2019 19:46:03:

Nick

I can only assume you are joking with this line.

"And as CADCAM means that accuracy can be maintained with little or no skilled input"

Having been lucky enough to work with some of the most skilled and talented toolmakers and machinists on the south coast, I never saw the work that they done to have been succesful without a lot of skill.

Like I say I think you were joking !

Regards

Barrie

I am sorry but no. The key word in my post was maintaining. Setting up a production process takes skill and knowledge and the toolmaking is obviously skilled as well, but unlike a manual or semi manual (eg capstan) system which needs a skilled operator, once it has been set up the task becomes one of machine minding and inspection of product.

I can't really make sense of your sentence, but I assume you are referring to manual machinists and toolmakers which were not what I was referring to in my post, quite the reverse in fact.

Nick

[Former MemberParticipant @formermember32069]

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[Nick Clarke 3Participant @nickclarke3]

Thank you for your reply Barrie, however I was intending to comment on tool production in the far east, not the one off or small batch work you have no doubt a great deal of experience in.

As I said I was not commenting on setting up, either for one off or quantity but rather running a production process.

I think we are posting about two different things so, accepting your absolute right to agree/disagree or understand/misunderstand me I will leave it there.

Take care,

Nick

[Ian Skeldon 2Participant @ianskeldon2]

Duncan (or anyone else) do you have a link to the project that uses the ardunio to make an accurate tacho such as the one you have made? I was thinking of getting one of the ones on ebay for my Myford mill but after reading your post I guess it was too good to be true to expect a tacho that would work and continue to work for that price.

Does anyone know if there is a tacho that you can buy where all that is needed is placing of the magnet and some simple wiring?

TIA ,

Ian

[Former MemberParticipant @formermember32069]

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[duncan webster 1Participant @duncanwebster1]

Posted by Ian Skeldon 2 on 21/06/2019 21:04:52:

Duncan (or anyone else) do you have a link to the project that uses the ardunio to make an accurate tacho such as the one you have made? I was thinking of getting one of the ones on ebay for my Myford mill but after reading your post I guess it was too good to be true to expect a tacho that would work and continue to work for that price.

Does anyone know if there is a tacho that you can buy where all that is needed is placing of the magnet and some simple wiring?

TIA ,

Ian

I've never suggested that the Chinese ones were rubbish, in fact it looks quite well made, the problem is the update rate. if you just want to measure the speed of a steadily rotating shaft they are fine, for adjusting something which has a high acceleration not so good.

If you send me a pm I'll try to find the schematic of my home brewed one, you can certainly have photos and the code, but it does involve soldering a very simple stripboard circuit. However my hard drive can be a little difficult to navigate (chaos might be a better description), so it might take a couple of days

[Neil WyattModerator @neilwyatt]

Posted by JasonB on 21/06/2019 18:34:49:

Posted by Barrie Lever on 21/06/2019 17:15:21:

I must be running around in a bubble not noticing these Chinese brand names, but I am not likely to if they have a Curry's badge stuck on them, silly me !!

" All available in your local branch of Currys, under their own brand name."

Hardly hiding behind a label.

I read that as being under Curry's own brand… not sure which it means now!

N.

[JasonBModerator @jasonb]

Neil, a quick search of Curries store will show each of these brands under their own name not Currys, though I expect the same machines can also be bought with a Currys lable for those that don't want to touch Chinese products and they will go away happy shoppers..

[Brian OldfordParticipant @brianoldford70365]

Posted by duncan webster on 21/06/2019 22:50:02:

I've never suggested that the Chinese ones were rubbish, in fact it looks quite well made, the problem is the update rate. if you just want to measure the speed of a steadily rotating shaft they are fine, for adjusting something which has a high acceleration not so good.

If you send me a pm I'll try to find the schematic of my home brewed one, you can certainly have photos and the code, but it does involve soldering a very simple stripboard circuit. However my hard drive can be a little difficult to navigate (chaos might be a better description), so it might take a couple of days

Duncan

The organisation of your filing system is similar to mine. However you took a somewhat different route than I am taking to resolve the problem.

I'm investigating the possibility of decreasing the sample time and increasing the number of pulses sampled by increasing the number of magnets passing the Hall effect device.

Whether or not will be successful remains to be seen.

[Nick HulmeParticipant @nickhulme30114]

The stuff you buy from China which is crap is that way for a reason, it's because you're cheap! 😀

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