Precision V-blocks (32mm & 7") - any UK buying advice ?

I did find the side groove useful for clamping a pair to the mill table when working an a part that needed to come out and go back into the blocks a number of times, being a deeper side groove than usual the hold down clamp fits well.. The type of clamp shown doe shave the advantage that you can still use it if block is laying on its long side or stood vertically in a vice.

To the OP the clamps are not there to apply a great deal of force, mostly just to stop a part moving when measuring or marking out so unlikely to suffer failure, if machining then a proper clamp should be used.

Funny enough Dave should say he has not seen anyone complaining about Vee blocks and those saying non descrpt ones will be no good. Similar comments in a previous post is what prompted me to make that video of just such a non descript block. which far exceeds John's accuracy requirement.

John what are you using these Vee blocks for I get the feeling they may well be for jigging your plates with the "accurate" 45deg bevel that turned out to be +/- 1 deg

Edited By JasonB on 20/04/2021 07:50:29

Remember that V blocks are fixtures for holding things in the V and so the V may be 90 degrees, but is not usually specified. The only time 90 matters in the normal use of a V is if you are fixing square stock, and in that case a slightly more closed V might actually be better as it will have 2 line contacts, where as unless the stock is actually 90 degrees and perfectly finished it might seat in an unrepeatable manner.

I have 3 pairs about the size you are looking at I can measure the angle of later.

For angle fixturing you really want an angle fixture of some sort - like a sine table (for instance)

Dave

Seems the OP wants a silk purse but will only pay for a sows ear? If you truly want or need an accurate set of vee blocks paying less than £40 is unlikely to satisfy your requirements, I will leave it at that.

Tony

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BS 3731:1987 ... Specification for vee blocks

Makes interesting [and concise] reading.

MichaelG.

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Ref. https://shop.bsigroup.com/ProductDetail?pid=000000000000176247

Edited By Michael Gilligan on 20/04/2021 09:22:20

It's in your specification John: 'Budget: £40? (but hopefully a lot less)'

Fully specified V-Blocks are outside the budget. This pair from Cutwel are £110. Note my example is the smallest and cheapest in Cutwels range and prices rise with size. A pair of 100x80x80mm blocks will set you back £225, plus post and packing. Not the most expensive either: 6804 blocks in 90x48x48 are £380 each.

Money is a cruel mistress!

Dave

A long time back I bought a pair from Chronos which spend most of the time in their box and have probably been use twice in 30 years or so. More recently (but still must be 20 years back) I saw a pair of Mitutoyo ones on my favourite tool stall for £25 so bought those. They are a bit bigger so have been used more but still not much. The fact that they were £25 20 years ago tells you that quaility isn't cheap.

+1

I've got a dozen or more V-blocks, mostly made by people as part of their apprenticeships, plus a couple of commercial sets by reputable makers. But like JohnH I rarely use them; the Eclipse set are still in their original box and anti-rust protection. I couldn't immediately find any photo in my albums where I'm using V-blocks.

Andrew

Pedant alert! I believe Steve has it the wrong way round. I think RDG, via another company, bought the brand, stock and other assets at Myford's closing down sale, and then renamed the purchasing company as 'Myford Ltd'. Nigel did an excellent job tracing who owns Bassett Lowke - perhaps he can do the same for Myford? I hope the new new incarnation will be profitable for many years, but it;'s not the original Myford.

Looking at RDG Online's offerings, the company sells a wide range of engineering tools. A mix of high-end down to extra cheap. RDG don't appear to specialise. The stuff I've bought from them has been fine, but I avoid 'too cheap' and don't have excessive expectations of hobby tools.

Can I warn again about getting too hung up on brand-names? These days there is no direct link between 'quality' and the supplier unless the supplier chooses to play it that way, which can change with the fortunes of the company. I feel it's more important to buy from a reputable supplier who will refund or exchange in the event faulty goods are supplied. There are no risk free purchases.

Good service should be rewarded with repeat business, but stay alert! Ma and Pop businesses are particularly vulnerable: I'm aware of a number of decent boiler makers coming unstuck to illness or personal problems. Unable to deliver on time they got into a commercial death spiral due to shortage of time and cash, causing reputational damage and eventual collapse. Big firms have the opposite problem; must be hard to train school-leavers to deal effectively with grumpy expert customers demanding top-quality advice about the arcane technical details of a thingy sold for £1 profit! I'm inclined to give firms the benefit of the doubt at least once.

Although some UK hobby tool vendors are more consistent than others, I'm not aware of any who should be avoided at all costs at the moment. Not had a major problem with anyone in over ten years. Buying off the web is a different story - mostly OK, but I'm always prepared to lose my money.

Dave

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[pedant alert ^2] ...

The same individuals are Directors of both Companies, but the Companies stand alone.

It’s all a matter of public record

MichaelG.

Funny how people use tools differently.
I use my V blocks all the time. So much so that I bought another 2 pairs.

Tjose ones are SPI from MSC and are, I would say, middle of the road on the price / performance scale - about £90 for 2 pairs of different sizes, claimed match to 0.0005”. They are numbered and I suspect match better than that as if you finish grind in a pair they really should be dead on.

Dave

Apart from the usual Eclipse and Starret made Vee Blocks I picked up some excellent adjustable ones with a very thin 'web' which allows most crankshafts to be mounted on a surface plate.

I think these came from MSC - probably out the 'clear out' corner a few years ago. Made by SPI and excellent quality.

Martin

If this is any help,

The closest to your budget that Arc Euro offer are a pair with a 31 mm dia capacity (£47.48 ) or 37 mm capacity at £52.07. Stated to be hardened to HRC 52, the 37 mm pair are stated as "Ground as a pair for accuracy"

Catalogue 11 prices, plus carriage.(£3.60 )

Howard

Hi Howard,

Catalogue 11 prices, plus carriage.(£3.60 )

If he were to order two pairs, they would be carriage free?🙂

Did a little measuring. The SPi blocks are as expected within 0.0001” in their pairs. The included angle is 89 degrees and 40 mins on the larger and 89 degrees and 50 mins on the smaller. So pretty close to 90, but just under.

The well used Brown and Sharpe pair are within 0.0003” of each other, but their angle is 91 degrees.

The vernier protractor measures 90 spot on with my “master square “ so whilst not traceable or calibrated I believe it for the roughness of these measurements.

Will 10 or 20 mins matter is something that the OP must decide, but clearly unless there is a spec and tolerance stated on the groove angle it might not be “exactly 90 degrees”

This is something to be aware of if you are planning to use a “precision” item for its none intended precision operation. Just because it was made with precision doesn’t mean it has the actual precision you need - unless the spec sheet says otherwise (and you can trust the spec sheet, but that is a different matter...)

Hope that is useful

Dave

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A very useful ‘reality check’ Dave

It is interesting [and I think ‘proper’] that the Standard gives ‘permitted deviations’ for

Equality of semi-angles of vee flanks

and for

Centrality of vee

and various other significant measures

... but there is no specific requirement for a 90° full angle.

MichaelG.

Tony, are you calling accuracy to 1/1000 inch (0.02mm) on a 3 inch V-block "a silk purse"?
As far a the 45 degree chamfer goes it needs to be accurate to within 1°.

The problem with V-blocks that have that "bridge style" design is that the screw threads take up valuable lateral space. This means that the central V-becomes too small. For this reason I would need to go for a slightly larger V-block than 1 3/8inch (35mm) - maybe more like 2 inch (50mm)...

Btw, I was slightly tempted by this design:

**LINK**

Even though its U shaped clamp is taking up a lot of space above the part, it allows you to 'bury' the sides of the U-shaped clamp a little using the stepped sides, plus I like the way that you can clamp stuff with parallel sidesfrom a 45 degree angle.

Apart from being silly money (GBP105) the spec looks promising.

"Stepped groove construction. z 90° V groove are central, parallel and square with all surface within .0003”. z Harden steel ground. z Two clamps only order No.: 420-5491. z Sold in pair"

To be fair, it's a fraction larger than I really need, as well as (if we believe them) it is more accurately ground than I need, but it's a clever design and at least it is claiming a genuine 90°. The 45° screw doesn't look like it can cope with huge forces but it would probably be strong enough for my purposes.

I can't really justify the cost, but I'm tempted... Any thoughts?

J

PS Although I do like the idea of being able to clamp stuff from 45°, I slightly worry that the screw will be weakening one side U of the clamp, particularly the way they have failed to build in a collar around the 45° screw so as to reinforce it in the same way as the central screw has been done.

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Then, today : I can't really justify the cost, but I'm tempted... Any thoughts?

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Your gut reaction impressed me yesterday, John ... but now you are considering something with an almost meaningless description:

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MichaelG.

Hello

Just to let you folks know that as well as the smaller v-blocks, I have also just bought the large RGD Vee-Blocks.


VEE BLOCKS 182mm long x 62mm wide x 134mm high

https://www.rdgtools.co.uk/cgi-bin/sh000001.pl?WD=vee%20182mm%20block&PN=VEE%2dBLOCKS%2d182mm%2dlong%2dx%2d62mm%2dwide%2dx%2d134mm%2dhigh%2d2547665%2ehtml

Unlike the smaller ones that I bought, to be honest these large v-blocks will partly be used for random thing like keeping things square whilst the glue sets! but I'll let you know how I get on with them!
 

Edited By John Smith 47 on 27/04/2021 13:43:02

Edited By John Smith 47 on 27/04/2021 13:43:25