Magnetic v-blocks - how useful these are?

There are on offer on ebay Indian magnetic v-blocks. Cannot include url because it is very long link and I don't know how to shorten it.

Of course words "Indian" and "precision" does not mix well but anyway how useful such a tool might be?

How well are they holding barstock?

Would they be useful for cross-drilling a bar (where geting rid of clamps can be a great advantage) or maybe for light milling operations, particularly if bar can be axially supported on one end to take a force of cut?

Do you have any experience with these and if so then what is your opinion about them?

Edited By Martin Dowing on 24/02/2021 20:30:34

Edited By Martin Dowing on 24/02/2021 20:33:23

I have used mine to hold a length of rod whilst it was cross drilled, and it worked a dream. I was struggling with standard v blocks as the clamps kept getting in the way of the drill chuck.

Colin

Good tool which has many uses, such as; marking out, inspection, drilling and milling. Have not looked at the ones you have pointed to on eBay but as with any magnetic unit the quality lies in the magnets the physical properties of the 'Vee' are the mechanical aspect of quality.

I bought 2 units about 4" long and about 2 1/2" square, with a single deep Vee, accurately ground on all major surfaces. The switch was substantial, a metal 'wing nut' type. They are very powerful and were good VFM. They came in a nice felt lined wooden box, not that that in itself is any guarantee, but nice all the same. If you asked me where they originated I would have said either Taiwan or India.

Martin

I would expect them to be more useful for alignment than serious work-holding .. but I may be surprised.

What I can tell you though, is that everything in your ebay URL ... from the question-mark onwards, is ‘tracking’ rather than the actual address.

This should work fine:

https://www.ebay.co.uk/itm/Precision-Magnetic-Engineers-V-block-2-5-65x65x50mm-Workhold-Premium-vee-block/363030766520

**LINK**

MichaelG.

.

Edit: __ I am surprised already

Edited By Michael Gilligan on 24/02/2021 20:43:43

I'd be hesitant about using magnetic V blocks because they will literally be a magnet for dirt and chips. If you are trying to do accurate work location and holding, a bunch of dirt and chips stuck to a V block will not help much. Getting them really clean may be a real chore too if the magnets are strong. Don't do it, is my opinion.

Duct tape gets chips off magnets.

I have used magnetic V blocks many times and wish I had some now. I have only used Eclipse made ones and when you turn them off there is almost no magnetic flux. They were quite expensive to buy and hadn't looked for them since retiring. When at work we would use them to hold diameters to mill flats or drill holes in diamiter or square pieces as well as surface grinding as well.

David

I bought a big one, probably Indian origin last year, but have not yet used it. It checked out ok on the surface table.

Cling film is your friend when keeping magnetic devices swarf free.

One layer has no noticeable effect on magnetic grip but can easily be simultaneously lifted off and and wrapped around the swarf. Pretty much an essential trick with a permanent magnet device but useful with switched ones to as it keeps swarf out of the works.

Like David I can't say that I've ever missed having magnetic Vee blocks at home as I (so far) already have sufficiently good alternatives.

They are useful devices though.

How much so depends on what you do and what other kit you have. Not, I think, something to get because they ought to come in handy somewhen. More something to aware of to be gotten when the need arises. You will know it when you see it!

Clive

I would be wary of anything but the lightest cuts on a mill, I think they are best for grinding, marking out and inspection tasks.

Mike

If you believe that the terms ‘indian’ and ‘precision ‘ are mutually exclusive, it may be interesting to look up Jantar Mantar, Jaipur. I went there a few years ago, and was very impressed.

Bert

I have had a Mitutoyo magnetic vee block for 30 years,I rarely use it,the snag I found was that if you want to drill a cross hole in a shaft on a drilling machine,a centre pop on the shaft is set central by eye,then the mag "on" lever is operated,thats ok it holds the work resonably securely but the magnetism in the base stops the block being slid around on the drill table to get the centre pop under the drill point,I prefer an ordinary vee block,if precision is required then its either use a vee centre in the lathe tailstock or on larger round bar work its a machine vice on the vert mill set up central using a wobler tool.I have three sets of paired vee blocks ,plus a very precise Bilton single block and an Eclipse toolmakers vee vise. Though they all suffer with the snag of the drill chuck can hit the clamp on occasions. I do have a pair of old Verdict v blocks which have the an arrangement of slots on the sides of the block which contain the clamp so if the block is laid on its side the clamps do not foul the surface plate or drill table,My mag vee block came "free" I would certainly not buy one.My pair of Eclipse hardened steel vee blocks,are now 60 years old very expensive in those days bought at a small discount via the company apprentice tool scheme,though still in excellent condition.

I am aware of story from Myford (Beeston; N'gham) - they have ordered from India collets for ML7/S7 lathes - they had to be returned because specification was not met. So Indians made a new lot - also had to be returned.

This was long time ago. More recently I have purchased rotary table from Indian conpany - it was simply unusable.

Rotating part of this table was simply "wiggling" in its housing. I had a lot of troubles to make it working (remachining and loctiting of processed precision ring from bearing made a trick, though CBN insert have gone damaged in the process).

But it is a large country so surely somewhere must be few companies which are keeping good standard.

Anyway, many thans for comments all of you.

It seems o be useful device.

Nigel,

I have made myself a simple device (precision ground bar with 2 holes precisely crossdrilled & reamed 4 inches apart and exactly through center).

This allows me to set vee block exactly at centerheight and parallel to lathe bed (short section of precision rod hold in collet must pass without any resistance through these crossdrilled holes - made to h6/H7 fit.

Vertical slide is manipulated to achieve that.

Once done you are ready to for cross drilling. Setting milling machine would be comparable.

I use a website called TinyURL. It converts any URL into a very short URL that you can then use directly, or copy into an email or anything else you want.

Martin,

The quality of Indian magnetic stuff depends on maker. To the best of my knowledge, there is only one good maker near Delhi, but the probability of his stuff getting onto eBay is next to zero, because his product range is extremely expensive. There are plenty of small makers of magnetic V blocks in that region, but most are poorly made. The better makers are to be found in the south of India, such as in or near Puna, but again, very expensive, and selling on eBay would be outside their interest, as they are usually very busy working with big industry customers.

90%+ of eBay Indian sellers are extremely small traders similar to the one shown in Michaels G's link, with a small number being large stockists hiding behind different names for tax reasons, or to avoid conflict with their overseas agents/partners with whom they have territory distribution agreements which are made in their real name . They buy two to four pieces at a time of a product from a maker, as and when an order comes in. The makers are usually small scale cottage industry operations, and they usually have stock of good, bad and rejects, which they are happy to sell on to the eBay sellers at different rates. The product may or may not meet your requirement.

ARCs magnetic V blocks come from China only and we are happy with the product we sell. However, regardless of the force of the magnet, I would generally agree with Michael Pools comments: ' I would be wary of anything but the lightest cuts on a mill, I think they are best for grinding, marking out and inspection tasks. '

If you wish to buy Indian, you would be better to look at supply from Chronos - Soba range. Soba have an inspection process, and what ever they reject goes back to the maker, and what is left with the maker ends up on eBay. At least, if you are not happy with the product, you can always return it to Chronos.

Ketan at ARC

Edited By Ketan Swali on 26/02/2021 12:21:19