[StanRex]

Hey guys,

I ve got 2 little questions regarding casework.

First : the one that boggles me more

I have an rk27 and this volume knob : 45KN031

I ve tried attaching the knob to the pot using the small screw that is inside the knob, but the result doesnt feel too good. The knob simply tends to slide on the shaft of the pot.

My question was : should I drill a hole in the shaft of the pot and line it with the screw inside the knob? or is there another trick?

And my last questions , regarding safety this time : I ve cut a few round holes in an aluminum case using a dremel with a cutoff wheel, and found it created quite a bit of dust.
Would you suggest buying protection glasses/mask or are those only useful for pro and not hobbyist who aren't exposed as often?

thanks in advance for your answers

 

[alfie]

1 The knob shaft size is mm. 6.35, while the rk27 is 6, so add something around the rk27 shaft.

2 With dremels glasses are always usefull

 

[pabbi1]

Quote:

Originally Posted by alfie /img/forum/go_quote.gif 1 The knob shaft size is mm. 6.35, while the rk27 is 6, so add something around the rk27 shaft. 2 With dremels glasses are always usefull

With Dremels, glasses are REQUIRED, and in fact, I am looking at face shields, having taken one too many cutting wheel bits off my cheek and forehead. Same with drill and stepped bits - any flying aluminum between the lid and cornea is a really bad combination, and needlessly risked.

 

[cobaltmute]

Quote:

Originally Posted by pabbi1 /img/forum/go_quote.gif With Dremels, glasses are REQUIRED, and in fact, I am looking at face shields, having taken one too many cutting wheel bits off my cheek and forehead. Same with drill and stepped bits - any flying aluminum between the lid and cornea is a really bad combination, and needlessly risked.

With power tools, glasses are required - unless you like being blind.

 

[nikongod]

If you are making many holes of the same size a greenlee punch or stepped drill bit in the appropriate size is worth EVERY penny.

For most SS amps, the stepped drill bit is enough.

hearing protection is important too. Whats the point in destroying your ears with loud power tools while making audio gear...

 

[tangent]

Besides the 6mm to 6.35mm mismatch -- seems small on paper, but it really matters to the feel -- you have to tighten set screws pretty forcefully to get them to grip well. There's not much contact surface between them. The proper force is somewhere between scratching or denting the shaft and stripping the set screw threads.

 

[pinkfloyd4ever]

Quote:

Originally Posted by tangent /img/forum/go_quote.gif Besides the 6mm to 6.35mm mismatch -- seems small on paper, but it really matters to the feel -- you have to tighten set screws pretty forcefully to get them to grip well.

x2 (as if he really needed my backing to be legit)

but anyway I found this out too with the first cmoy I built. The 2 most popular places to get nice knobs cheap around here seem to be PartsPipe and vt4c. I'm sure other head-fiers know of some other good places too. Anyway, I bought a 2 pack of solid aluminum knobs from PartsPipe and got them in about a week (they ship from Hong Kong) so that's pretty quick for shipping halfway around the world IMO. Compared to the prices for similar, if not identical knobs some certain North American hi-fi component suppliers sell (ahem, no names will be mentioned

), they're very nice for the price, even when you factor in shipping. I personally haven't ordered from vt4c (yet) but I've heard similar good things about them (they're also in Hong Kong)

 

[srserl]

You can try wrapping masking tape around the pot shaft so that the knob just barely slides on, then tighten the screw into the masking tape. There is a chance that the screw may tear into the masking tape when turning the knob; just replace the masking tape, then add some clear fingernail polish over it. That may work if masking tape alone will not work.
Of course you will want to make sure no masking tape shows when people look closely behind the knob (like at a Head-fi meet).

 

[tangent]

Quote:

Originally Posted by pinkfloyd4ever /img/forum/go_quote.gif as if he really needed my backing to be legit

I do for now. But when I hit 5000 posts, I will be invincible!.

 

[StanRex]

Thanks to all of you for your answers. Gonna buy eye/ears protection soon and will try taping the shaft

 

[nikongod]

If it is a Chinese/Taiwanese knob, I have found that they usually come with "flat-faced" set-screws. Upgrading to "cupped" or "cone" tip setscrews designed to actually bite into the shaft also helps a little.

 

[tomb]

True, but if it's a Chinese knob, most likely they'll have a 6mm dia hole, anyway.

I've never had an issue with the knob-shaft fit on an RK27 by using the ebay Partspipe aluminum knobs:
2,30x22 Aluminum Hi-Fi CD VOLUME TONE CONTROL KNOB,B - eBay (item 300266144550 end time Nov-12-08 17:06:27 PST)
2pcs 24x25 SOLID ALLOY GOLD CD VOLUME TONE KNOBS KNOB - eBay (item 300271476929 end time Nov-12-08 23:47:10 PST)
2, 30x22 Aluminum Dimple Hi-Fi CD VOLUME Pointer KNOB - eBay (item 300271921063 end time Nov-14-08 23:43:57 PST)

 

[Navyblue]

Digging up this semi old thread as I don't want to start a new one.

- Some Partspipe knobs are advertised as 1/4", are they really 6 mm instead of 6.35 mm? VT4C ones are advertised as 6 mm.
- Can I ram 6 mm knob into 6.35 shaft without thinning down the shaft?

Thanks.

 

[Uncle Erik]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif Digging up this semi old thread as I don't want to start a new one. - Some Partspipe knobs are advertised as 1/4", are they really 6 mm instead of 6.35 mm? VT4C ones are advertised as 6 mm. - Can I ram 6 mm knob into 6.35 shaft without thinning down the shaft? Thanks.

Knobs can be kind of a pain to deal with. I wouldn't ram a knob onto a shaft - you might damage the pot pushing it on. I've used a carbide bit on the Dremel to shave the inside of the knob to make it a little bigger. Just converted a "D" knob to a round one (it has a grub screw) and it worked OK.

As for the OP, another method is to buy a longer grub screw and grind it down to the length you need.

And always wear eye protection, always. If you wear prescription lenses, you can order prescription safety goggles for $40 here:

Prescription eyeglasses online, fashion designer eyeglasses, starting $7.95 - EyeBuyDirect

I ordered some. Haven't arrived yet, but $40 for good protection is a great investment. That's a good place to order glasses from, too.

 

[JamesL]

Drill out a larger hole if you need to, but never try to force a knob on if it doesn't want to fit.

I once used a knob that was advertised as 6mm on a 6mm shaft, and it turned out the pot's hole was slightly smaller due to bad manufacturing tolerances..
The knob got stuck on the shaft, and I ended up pulling the shaft from the pot itself.