SME graunching

Nam402 · 22nd June 2006, 10:55 AM

Hi folks,

I've noticed that the little grub screws for adjusting SME arms can be easily graunched. The readily available 1.5mm hex keys are a loose fit in the screw socket, and if there is already some wear there could be a problem with a tight one. No adjustment!

I had a close call with my arm, and am now very careful not to overtighten.

Did SME provide a custom key for their arms? Can we get them?

Cheers, Nam

sreten · 22nd June 2006, 11:33 AM

Hi,

Its because SME use AF sizes not metric.

Available from your local "everything a pound" shop.

/sreten.

Nam402 · 22nd June 2006, 02:01 PM

Thanks Sreten; that was easy!

Cheers, Nam

Nam402 · 22nd June 2006, 06:33 PM

Hi Sreten and folks,

I've tried the Blackspur keys.

Unfortunately this 'small' matter is a little more complicated than I thought. Under a glass with micrometer, the 1.5mm and 1/16" keys are identical, and both are too small in section for the SME grubscrews, the same goes for Proskit 1.5mm keys of course, which are a little sharper in section than the Blackspur but still too small.

There is a company, I don't know if I can mention them here, who supplies AF keys measured in mms across the flats. They have 1.5mm and 1.6mm AF and I am going to try these.

Given the value and collectability of some SME arms, and the problem of stuck grubscrews, I think it's worth getting just the right keys.

Lucky I caught mine in time, before it was too late!

Cheers, Nam

graeme uk · 23rd June 2006, 11:18 AM

can you get the grub screw out?
If so, get a small bolt that fits, grind the end to a point (i assume the origional grub screw has a point), cut it to length (cutting the bolt head off) and cut a slot in the end so you can use a small screw driver.
Just a thought, without owning this are, or seeing where the screw is, but ive replaced a few grub screws this was.
Small allen head bolts/grub screws are prone to rounding out.

EC8010 · 23rd June 2006, 04:08 PM

Quote:

Originally posted by graeme uk
Small allen head bolts/grub screws are prone to rounding out.

Only if you don't use the correct key! Try an engineering shop rather than a cheap and cheerful shop. They will have more choice and better quality. As far as I remember, the SME uses British Association grub screws (6BA).

audio-kraut · 23rd June 2006, 05:24 PM

I am using a standard allan key set (imperial sizes) on both of my sme arms w/o any problem.

Nam402 · 26th June 2006, 07:42 AM

Hi audio-kraut,

When you insert the key into the screw, try checking how much play there is. With mine, and the 1.5mm Proskit key or 1/16" equivalent, I can turn the key a quarter turn without resistance. This is very sloppy. On tightening, I found that the key slipped round under pressure, and I didn't try it again. Under a glass, there is only a little graunching so far.

I'm still waiting for some specialist keys to arrive in the mail.

Cheers, Nam

Nam402 · 26th June 2006, 09:12 AM

Hi folks,

I have obtained some keys from a model engineering company.

These are 1.6mm AF hexagon keys and are a snug fit with the SME. They would probably even work with worn grubs.

Looking at the standard 1.5mm or 1/16" keys there is a big difference even to the naked eye; these custom keys are much more substantial.

If anyone wants the link, just PM me. The keys were 50p each plus p&p.

Cheers, Nam

sreten · 26th June 2006, 11:21 AM

Hi,

Well the Blackspurs claimed to be A.F. sizes, obviously not. Seems
that you get what you pay for. An AF set should have these sizes :

1/16" 5/64" 3/32" 1/8" 5/32" 3/16" etc i.e. they are imperial.

/sreten.

22nd June 2006, 10:55 AM	#1
Nam402 diyAudio Member Join Date: Jun 2006	SME graunching Hi folks, I've noticed that the little grub screws for adjusting SME arms can be easily graunched. The readily available 1.5mm hex keys are a loose fit in the screw socket, and if there is already some wear there could be a problem with a tight one. No adjustment! I had a close call with my arm, and am now very careful not to overtighten. Did SME provide a custom key for their arms? Can we get them? Cheers, Nam

22nd June 2006, 06:33 PM	#4
Nam402 diyAudio Member Join Date: Jun 2006	SME graunching update Hi Sreten and folks, I've tried the Blackspur keys. Unfortunately this 'small' matter is a little more complicated than I thought. Under a glass with micrometer, the 1.5mm and 1/16" keys are identical, and both are too small in section for the SME grubscrews, the same goes for Proskit 1.5mm keys of course, which are a little sharper in section than the Blackspur but still too small. There is a company, I don't know if I can mention them here, who supplies AF keys measured in mms across the flats. They have 1.5mm and 1.6mm AF and I am going to try these. Given the value and collectability of some SME arms, and the problem of stuck grubscrews, I think it's worth getting just the right keys. Lucky I caught mine in time, before it was too late! Cheers, Nam

26th June 2006, 09:12 AM	#9
Nam402 diyAudio Member Join Date: Jun 2006	SME graunching - problem solved! Hi folks, I have obtained some keys from a model engineering company. These are 1.6mm AF hexagon keys and are a snug fit with the SME. They would probably even work with worn grubs. Looking at the standard 1.5mm or 1/16" keys there is a big difference even to the naked eye; these custom keys are much more substantial. If anyone wants the link, just PM me. The keys were 50p each plus p&p. Cheers, Nam

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22nd June 2006, 11:33 AM	#2
sreten diyAudio Member Join Date: Nov 2003 Location: Brighton UK	Hi, Its because SME use AF sizes not metric. Available from your local "everything a pound" shop. /sreten.

22nd June 2006, 02:01 PM	#3
Nam402 diyAudio Member Join Date: Jun 2006	Thanks Sreten; that was easy! Cheers, Nam

23rd June 2006, 11:18 AM	#5
graeme uk diyAudio Member Join Date: Dec 2005 Location: essex	can you get the grub screw out? If so, get a small bolt that fits, grind the end to a point (i assume the origional grub screw has a point), cut it to length (cutting the bolt head off) and cut a slot in the end so you can use a small screw driver. Just a thought, without owning this are, or seeing where the screw is, but ive replaced a few grub screws this was. Small allen head bolts/grub screws are prone to rounding out.

23rd June 2006, 05:24 PM	#7
audio-kraut diyAudio Member Join Date: Apr 2004 Location: 12km off the alaska highway in northern BC	I am using a standard allan key set (imperial sizes) on both of my sme arms w/o any problem.

26th June 2006, 07:42 AM	#8
Nam402 diyAudio Member Join Date: Jun 2006	Hi audio-kraut, When you insert the key into the screw, try checking how much play there is. With mine, and the 1.5mm Proskit key or 1/16" equivalent, I can turn the key a quarter turn without resistance. This is very sloppy. On tightening, I found that the key slipped round under pressure, and I didn't try it again. Under a glass, there is only a little graunching so far. I'm still waiting for some specialist keys to arrive in the mail. Cheers, Nam

26th June 2006, 11:21 AM	#10
sreten diyAudio Member Join Date: Nov 2003 Location: Brighton UK	Hi, Well the Blackspurs claimed to be A.F. sizes, obviously not. Seems that you get what you pay for. An AF set should have these sizes : 1/16" 5/64" 3/32" 1/8" 5/32" 3/16" etc i.e. they are imperial. /sreten.