Skate Bearings - Big Brother ???

used a pair salvaged from lawnmower replacement wheels for the lift screw bearings on my sawmill.

support the wheels on the HF 1 ton gantry trolley, and the trolley I made for an HF 1300# electric hoist.

Their catalog is a lesson in what's available in mechanical and hydraulic components.

Hi, Bob. Can't answer the question. But, several years ago I bought a used/abused Chinese metal band saw at a local business "garage sale". $35.00. Keep it at the plant. Similar one at home.

The abused one needed bearings. Checking for them on-line, I discovered the number matched the bearings for skate boards and bought a bunch on Ebay. Worked ok and saw is still going strong.

My identical saw at home uses a different bearing number and I never check what the difference is.

Paul

I use those 608s for the blade guides on my sawmill. They clog, but both the Z and RS are easy to open with a safety pin point to clean and regrease (or oil).

Big brother equivalent is alternator bearings. 10x30x9

That's the 6200, $2.80. Let's see if this copied link works better:

$8.99, FREE Standard Shipping

All regular ball bearings are very cheap nowadays and even cheap ones are well enough made for miscellaneous use. Enormous progress in making them cheaply and industrially. No need to hoard bearings, just buy them as you need them cheaply.

i

And for a lot of applitions you can use uhmw pe. Much cheaper than bronze sleeves. You can buy rod of it from Grainger and MSC.

Dan

All regular ball bearings are very cheap nowadays and even cheap ones are well enough made for miscellaneous use. Enormous progress in making them cheaply and industrially. No need to hoard bearings, just buy them as you need them cheaply.

i

In Yuma, Az there is one major bearing reseller that I am aware of and the few times I have priced anything from them they seemed to think this was still the 1970s where I had the choice of buying from them or doing without. Other than that there are the usual hardware store bin bearings which are typically only small sheet metal ball bearings suitable for movement with light loads. There are a couple other sources, but they all say, "we can get it for you." Now I am not talking about a particular spec bearing to repair an old machine. For those I always get a high quality spec bearing to match the old one, and often I have to check multiple sources to find somebody who has it or has a good quality crossover. They are almost never cheap.

In this case its more along the lines of deciding I want to build something. Usually in the evening or on the weekend when I have shut down production in the shop. Sure I can't have everything, but I can have a lot. Skate bearings are pretty amazing. 4 of them can handle a thousand pounds rolling load for a while, and a few hundred indefinitely with a quality grease. When you think about it that's insanely good for such a tiny little bearing. Put some preload on them and you can even make a light duty spindle out of them (I have) that's perfect for cross drilling or cross tapping on the lathe. I don't know how long they will last as my first one shows no signs of wear yet. I was just looking for a couple larger bearings I could spend a couple hundred bucks on and have a bunch of them in the project bearings drawer on my back assembly bench for those weekend inspiration projects.

For me usually the shaft diameter determines the inch or metric bearing. Hardware store and second-hand pulleys are typically inch and may be difficult to rebore accurately, so they need inch shafts and bearings. When I make everything from scratch I can use metric sizes. Ultimately the motor torque or the axle load defines the minimum shaft diameter, see my thread on Lovejoy couplers.

The temporary setups I've seen in engineering labs were often built from 80/20 extrusions and pillow blocks. The local bearing supply house told me 3/4" and 1" are the most common shaft sizes they sell for prototyping.

Truer words were never spoken.

I like to salvage the shafts from gas struts. I'll put the horizontal

4"x6" outside, and set up the cut, then step back while they spray oil when they vent. The shafts are usually 6mm or 10mm, so matching bearings would be metric. I order some bearings from McMaster, or if I want special seals or materials like marine, I'll use Boca Bearing. They specialize in smaller bearings for r/c cars, fishing reels, etc.

Pete Keillor

How about ten for $19.77 with free Prime delivery from Amazon?

6204-2RS 20x47x14mm size, double rubber shielded. commonly used in riding mower decks. Might make good machine skate bearings.

How about ten for $19.77 with free Prime delivery from Amazon?

6204-2RS 20x47x14mm size, double rubber shielded. commonly used in riding mower decks. Might make good machine skate bearings. ********************************

That's one of the bearings (6204) that has been suggested.

Bandsaw blade guides are the only application I have where the choice of bearing isn't determined by the bore of something else on the shaft and the available space and method for holding the OD. Usually I have to buy the bearings to fit the particular requirements instead of designing around the contents of my spare parts bin.

What has been useful is key slot broaches and matching key stock. I make the guide bushings and shims as needed. Keys don't need to be the same size top and bottom, or even aligned:

Bandsaw blade guides are the only application I have where the choice of bearing isn't determined by the bore of something else on the shaft and the available space and method for holding the OD. Usually I have to buy the bearings to fit the particular requirements instead of designing around the contents of my spare parts bin.

*** I have MADE a bunch of stuff based on the bearings I had handy. I thought I said it in the first post that these are to have some on hand when I just want to "MAKE" something at night or on the weekend and not have to put it on the shelves of unfinish projects until the bearings come in. As long as it will handle the load I can always make a shaft fit a bearing. I think I also said when I am repairing a piece of machinery I just order a quality exact match bearing. I make things. LOL. I don't just fix things.

What has been useful is key slot broaches and matching key stock. I make the guide bushings and shims as needed. Keys don't need to be the same size top and bottom, or even aligned:

*** Shaft keys are amazingly tolerant. On wheels/pullies I often cut the slots on the mill with a small end mill. If the sides are square and the right dimension the set screw takes care of the rest. On most shafts I just throw them on the mill and slot them. I like to use a smaller end mill, and then finish to final dimensions so I "do" get a pretty good fit. Not a big deal on mono directional applications, but on bi-directional applications good fit helps. I like to have to lightly tap it together with a brass hammer.

I bought a small assortment of bearings for future projects and so far have used only the 608 skate bearings. At the time I thought I'd need

60xx bearings for small electric motor projects but now I build for gas engine power.

When I built the sawmill I bought extra L095 couplers and spiders and considered stocking up on more 3/4" and 1" keyed shafting and pillow blocks. I haven't needed the shafting and had to change to larger L099 couplers.

My hardware stock consists of a few pieces each of many sizes. I build with whatever I have on hand and then restock or buy better suited parts.

I just bought 10 R8-2RS bearings on Amazon for $8.99. The page now shows them out of stock, but there are other vendors at $13.99 for 10. They are inch sized, 1/2" ID, 1-1/8" OD, 5/16" W. Max load is 500#, max speed ~30k RPM, though perhaps not for that batch. I got them to make larger roller blade guides for my sawmill, as they are what Woodmizer uses.

R12 bearings for 3/4" shafts can be had at $18.75 for 10.

Thanks Jim. I actually have some R8-2RS bearings in my desk. (I really need to get more organized). I think they are the spindle nose bearing for one of my old wood routers. If its the one I recall it turned 28K.