Tape Project Forum

Tape Machines => Reel to Reel Tape Machines => Topic started by: Black Witch on February 14, 2019, 01:50:58 am

Title: A80 bearings and where to buy them?
Post by: Black Witch on February 14, 2019, 01:50:58 am
Hi all.

I have an A80/R machine and the bearings are a little noisey so I'm looking to replace them.

Does anyone know which type are best and where to buy them?

I've been recommended the SKF W619002Z Stainless Steel Metal Shielded found here:
https://simplybearings.co.uk/shop/p12600/SKF-W619002Z-Stainless-Steel-Metal-Shielded-Thin-Section-Deep-Groove-Ball-Bearing-10x22x6mm/product_info.html (https://simplybearings.co.uk/shop/p12600/SKF-W619002Z-Stainless-Steel-Metal-Shielded-Thin-Section-Deep-Groove-Ball-Bearing-10x22x6mm/product_info.html)

...as well as the metal bearing type found here:
https://simplybearings.co.uk/shop/p6766/SKF-619002Z-Metal-Shielded-Thin-Section-Deep-Groove-Ball-Bearing-10x22x6mm/product_info.html (https://simplybearings.co.uk/shop/p6766/SKF-619002Z-Metal-Shielded-Thin-Section-Deep-Groove-Ball-Bearing-10x22x6mm/product_info.html)

The stainless ones are double the price but what about ABEC 7 type? I've read on a thread here that they are much quieter than the SKF types but where do I find them?

I want to get a good compromise in price too, the best if I can.

I'm based in the UK.

Any help would be great.
Thanks
J
Title: Re: A80 bearings and where to buy them?
Post by: docb on February 23, 2019, 04:19:17 pm
SKF is a manufacturer brand, not a tolerance rating. ABEC is a tolerance rating. Look for the highest ABEC rating you can find. This one is touted to be very quiet and ought to work.

http://www.wychbearings.co.uk/61900-LLB-ABEC5-Enduro.html (http://www.wychbearings.co.uk/61900-LLB-ABEC5-Enduro.html)
Title: Re: A80 bearings and where to buy them?
Post by: Black Witch on February 27, 2019, 07:07:42 am
Thanks, I'll take a look :)

I thought skate bearings wouldn't be good enough.
Title: Re: A80 bearings and where to buy them?
Post by: High and Outside on March 12, 2019, 01:57:40 am
Unfortunately most of the specs that get published about bearings don't say anything about what really matters for our purposes. This is the reason that Studer tested and carefully selected the types that they used.

In our application the bearing is sometimes used at high rotational speed--when fast winding--but the only area where performance really matters is at low speed: playing and recording. And the highest value should be placed on low vibration at low speed--similar to low noise but really it's vibration that will put flutter into the tape travel and change the audible character in the recording. 

Going for the highest ABEC rating unfortunately is no guarantee of low vibration performance. Neither is the material: steel, stainless steel, chrome steel or ceramic. You probably want ABEC 5 or better, just to make sure the bearing's dimensional tolerances are well controlled.

There are two aspects that are important, without a doubt. One is the lubrication: the right lube, in the right amount. A good bearing vendor will be able to give you a choice of lubes, or sell you unlubed bearings if you want to experiment on your own. The other is making sure the bearing is loaded properly. Part of that is choosing a bearing that is correct for the place it's used in the machine--whether that use provides lateral or radial loading. Then you must make sure that the way the bearing is installed properly provides the designed loading. If you are replacing bearings in your A80, pay attention to the washers as you take the old bearing out. They are there for a purpose. Assuming that your replacement bearing is dimensionally an exact match for the one you took out, then replacing the same washers should provide the same loading. If its even a thousandth or two thicker or thinner, then you might have to adjust on the washer(s).

Don't just throw a "good" bearing in there and hope. Check how the new bearing works, using your hearing and your tactile sense, and don't call the job done until you're satisfied that he new one is running smoother than the one you replaced. There's an old mechanic's trick that is very helpful here: get a length of flexible tubing, about a half meter or so, with an inside diameter somewhere around 13 mm. Hold one end of the tube near one of your ears, put an ear plug in the other ear, and bring the free end of the tube near the various parts of your deck as it pulls tape. You'll be amazed how much this magnifies the sound. Put another way, you'll be amazed at how noisy all the mechanics of your deck are. The closer you are to the heads, the more important it is to reduces those noises. (You might also be surprised just how much noise comes from the tape itself scraping over the heads.)
Title: Re: A80 bearings and where to buy them?
Post by: Black Witch on March 13, 2019, 01:54:20 am
Thanks for the informative reply.

That's great! :)

Does anyone know what type of lubricant should be inside the bearing?