# VST baskets and 'big' tampers



## jeebsy (May 5, 2013)

In short the Push tamper is amazing so I sold my old ridged baskets (slightly sticky with the Push) and tamper during the week.

I got some new ridgeless 18g baskets to use with the Push (use a 20 at home but 18 on the stall).

  Photo by wjheenan, on Flickr

For some reason, before leaving for an event last night I thought I'd check the new baskets out for a shot. Was concerned when this happened:

  IMAG2680 by wjheenan, on Flickr

Completely jammed. Took a lot of effort to wedge it out. The Push barely gets past the rim of the basket, it's so tight.

I emailed Pete from Push who seemed really surprised at this and kept in contact with me throughout the day - he's swapping my two new baskets for ones he knows fit which is great of him.

Borrowed a 58.4 tamper for the event but that felt really tight in the basket, much tighter than a 58.4 normally would.

I contacted VST to ask about it, here's the exchange (I said I had a Pergtamp as thought they might show some deference to Matty P):



> I have been using vst baskets for ages. I recently picked up two new 18g ridgeless but my tamper doesn't fit in them - it's too tight. All my other baskets are ok but these are much tighter, even my 58.4 tamper feels much more snug than usual. Has anything changed recently?





> Sounds as though you're referring to two different tampers, please clarify mfgr, model and dimensional data.
> 
> Our specifications remain unchanged, that is to advise a tamper at 58.35mm. Many tamper mfgrs have decided (at their own to risk) to deploy a larger diameter for a tighter fit than recommended by VST.
> 
> ...





> I bought the baskets from Jaguar Espresso in the UK.
> 
> I am using a Pergtamp (58.5) and a Pullman (58.4). Both tampers fit really well in my 20g VST and my 17g Strada baskets - but the 58.5 gets jammed in my two new ridgeless 18g VSTs. The 58.4 seems a much tighter fit in the 18g baskets too.
> 
> I appreciate your recommendations on tamper size but a lot of manufacturers are making bigger tampers (Pullman have just released a 58.6?) based on your previous specifications.





> As stated previously, our specifications have never changed. Some manufacturers of tamper products may have taken it upon themselves to measure what they had available and "assumed" it was representative of the range they would always see, versus the range actually w/in VST's actual range. We have warned both manufacturers that you named that anything exceeding VST's recommended size of 58.35±0.05 is done at their own risk. They are producing a machined tamper base that is easily controlled to about 0.03mm, a basket is a stamped product that is controlled to a much larger range of sizes, such as ±0.20. As you have seen in your small sample of VST baskets the 58.4 fits all, and may be slightly tighter in some vs potters, but fits all.


It would be interesting to try a 58.55 in them to see if it stuck. Pete from Push is going to measure the baskets and double check but this might be worth bearing in mind for people considering an oversize tamper (Push or otherwise)


----------



## risky (May 11, 2015)

Your "pergtamp" haha fits perfectly in my 18vst ridgeless. Obviously sticks so far down as the basket walls taper down.

I can bring a mic over and we can measure them if you like.

They don't say what size they aim to make the basket? Since they recommend 58.35mm +/-0.05mm for the tamper, and their manufacturing capability is +/-0.2mm.

So the basket could be anywhere from 58.05 > 58.65mm if their target size is 58.35mm? Fits with what they're saying about tamper manufacturers taking it upon themselves to make bigger tampers just because they've never come across smaller diameter baskets.


----------



## risky (May 11, 2015)

I think I measured mine once before and it was at that top end size. Works explain why my 58.35mm tamper was so slack.


----------



## El carajillo (Mar 16, 2013)

Just measured an 18 gm VST at 15 mm down from lip /top 58.55 mm (with precision vernier) at the top 58.8 mm


----------



## mrsimba (Mar 17, 2014)

18g VST here measures 58.73 at the lip & 58.58 on the sides


----------



## risky (May 11, 2015)

I presume we are measuring with recently calibrated measuring equipment here?


----------



## coffeechap (Apr 5, 2012)

I have noticed variances in the precision VST baskets for some time, interesting that they stipulate + or - 0.05 yet the 58.55 fits in most of mine, either the tamper or the baskets tolerances are not quite that accurate


----------



## mrsimba (Mar 17, 2014)

risky said:


> I presume we are measuring with recently calibrated measuring equipment here?


Nope! Just zero'd and checked but not certified calibrated so not sure what the +/- tolerance is.

but just measured my PergTamp at exactly 58.4 & Londinium tamper at 58.5 and both fit the 18g VST perfectly


----------



## johnealey (May 19, 2014)

Having only ridged baskets are people noticing the ridgeless are tighter?

I only ask as sure there was a recent thread that noticed a difference in a ridgeless vs ridged and noting Jeebsy's change from ridged to ridgeless could this also be a factor?

Could be completely barking, just a thought.

John


----------



## risky (May 11, 2015)

Just if anyone wants to approach vst with measurements they are obviously going to query the accuracy of those measurements.

I'll check mine again with a calibrated mic tomorrow.

@jeebsy the serial numbers are not that far apart. It's possible that the tooling was replaced just before yours were punched (or was due to be replaced) and they are therefore at the very bottom end of the tolerance.

@johnealey I have an 18 ridgeless and jeebsy's old tamper and it fits fine.


----------



## jeebsy (May 5, 2013)

Would replacing the tooling make the baskets smaller? Would it slacken off over time making the baskets slightly bigger?

Thought it was interesting that the two manufacturers were warned the tampers might not fit but at least one is being marketed as a super tight fit. Suprised this hasn't come up before if that's the case though.


----------



## risky (May 11, 2015)

jeebsy said:


> Would replacing the tooling make the baskets smaller? Would it slacken off over time making the baskets slightly bigger?
> 
> Thought it was interesting that the two manufacturers were warned the tampers might not fit but at least one is being marketed as a super tight fit. Suprised this hasn't come up before if that's the case though.


I would imagine the die (presuming that's how's these are made) wears and as a result the diameter gets bigger. Which would means yours were some of the first ones off the line with a new die, but I'll ask our sheet metal guys tomorrow.

As you say though, very odd this hasn't come up before.


----------



## Thecatlinux (Mar 10, 2014)

Temperature

just thrown that in the mix

Intresting post , I am sure it's not to much too worry about I would expect most,manufactors of precision parts to have a strict method of quality control , hence the individual traceability of each and every basket .

i always remember Mr dunderdale (my old metalwork teacher) imparting the knowledge that if you had a metal rod with a diameter of exactly 4mm and a hole in a piece of metal with a diameter of exactly 4mm that the rod would never pass through the hole .

@jeebsy Although possibly frustrating for you ,thank you for a refreshing and interesting post.


----------



## jeebsy (May 5, 2013)

Thecatlinux said:


> Temperature
> 
> just thrown that in the mix


I put the baskets in the group for a while to heat up and the tamper was sitting on the bench (outside, in Scotland, on a November evening) so each part should have been at its respective biggest and smallest later on. Was still barely fitting past the lip.


----------



## jeebsy (May 5, 2013)

Pete from Push has s/n 67563 and 67581 which fit so it would be interesting to know when they 'tightened up', and how often the tooling is replaced and we might go from baggy to tight


----------



## dsc (Jun 7, 2013)

risky said:


> Just if anyone wants to approach vst with measurements they are obviously going to query the accuracy of those measurements.
> 
> I'll check mine again with a calibrated mic tomorrow.
> 
> ...


 @risky what mic are you using to measure this? I haven't got an internal bore mic, but do have telescoping gauges which can be pretty accurate (indirect method of measurement so I'd use a mic as well) so I can give that a go.

I'm a bit surprised with the +/-0.2mm tolerance on the basket diameter, especially considering their tamper recommendation which is much tighter.

I'm guessing wear on the die will make the diameter smaller as the outside die dimensions get smaller as well. Maybe these baskets were made with an old on-it's-way-out die?

Also when measuring make sure you check the diameter several times by rotating the basket (and keep the tool level with the surface of the top rim), any roundness errors will quickly make a tight fitting tamper stick.

T.


----------



## risky (May 11, 2015)

dsc said:


> @risky what mic are you using to measure this? I haven't got an internal bore mic, but do have telescoping gauges which can be pretty accurate (indirect method of measurement so I'd use a mic as well) so I can give that a go.


I'm using http://www.mitutoyo.co.uk/small-tool-instruments-and-data-management/bore-micrometers/368-993

As I said above, +/-0.20mm isn't necessarily their tolerance, just their machining capability. They may have a stricter tolerance and discard baskets that fall outside the target size +/-0.1mm for example, which might not be many?


----------



## jeebsy (May 5, 2013)

Got two replacement baskets from Pete today and the fit hunky dory.


----------



## jeebsy (May 5, 2013)

risky said:


> I'm using http://www.mitutoyo.co.uk/small-tool-instruments-and-data-management/bore-micrometers/368-993


Wow.


----------



## risky (May 11, 2015)

jeebsy said:


> Wow.



Accuracy±3µm

Graduation0.005mm

Japanese gear...innit.


----------



## dsc (Jun 7, 2013)

risky said:


> I'm using http://www.mitutoyo.co.uk/small-tool-instruments-and-data-management/bore-micrometers/368-993
> 
> As I said above, +/-0.20mm isn't necessarily their tolerance, just their machining capability. They may have a stricter tolerance and discard baskets that fall outside the target size +/-0.1mm for example, which might not be many?


Is that your kit risky or work bought? I've been looking for one for a long time on ebay, but they usually go for mental monies or the sizes are wrong. To anyone buying Mitutoyo kit on ebay beware there's some China made stuff out there.

As for the tolerance indeed, although VST did mention machining tolerances for tampers and basket production dim ranges in the same sentence, which doesn't quite add up.

T.


----------



## risky (May 11, 2015)

dsc said:


> Is that your kit risky or work bought? I've been looking for one for a long time on ebay, but they usually go for mental monies or the sizes are wrong. To anyone buying Mitutoyo kit on ebay beware there's some China made stuff out there.
> 
> As for the tolerance indeed, although VST did mention machining tolerances for tampers and basket production dim ranges in the same sentence, which doesn't quite add up.
> 
> T.


Haha it's work gear sadly. Lots of wonderful gear to play with!

Yes it would be handy to know from VST what the inner diameter is actually intended to be.


----------



## 7493 (May 29, 2014)

VST 18g ridged, measured with (genuine) Mitutoyo caliper,

58.8mm average above the ridge.


----------



## El carajillo (Mar 16, 2013)

Does anyone know if they are "pressed" OR "spun" ??


----------



## Jon (Dec 3, 2010)

El carajillo said:


> Does anyone know if they are "pressed" OR "spun" ??


It says stamped above in Jeebsy's first post ? Not sure if that helps?


----------



## risky (May 11, 2015)

El carajillo said:


> Does anyone know if they are "pressed" OR "spun" ??


Given the shape, I'm not sure spinning would be possible? Don't really know enough about sheet metal work to know for sure though. Though a quick google suggests spinning has an accuracy of +/-0.2mm which fits with what they've said previously.


----------



## dsc (Jun 7, 2013)

I'm pretty sure these are pressed, spinning would probably take too long for batch production and you'd see it in the pattern on the material. If you look closely I think you can see it's been pressed as it's got vertical 'stretch' marks.

T.


----------



## yardbent (Aug 8, 2015)

just an aside

@risky - just received his MBK tamper quoted as 58.335

its a tight sliding fit in my brand new VST 18g ridged basket


----------



## risky (May 11, 2015)

*58.355

But your baskets are ridged so don't know if they are different internally?


----------

