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Type of Bearing?

Posted: Sat Feb 26, 2011 6:46 pm
by JDP12
I'm looking for an extremely frictionless style of bearing. I've used standard ball bearings in the past, but I'm looking for better. I'm designing my own centerpin fishing reel, trying to make a wooden one. You don't need to know anything about them- just watch this video and you'll see the type of frictionless bearing.

As you can see, it spins with virtually no effort. I've been looking around on mcmaster, and have found standard ball bearings, and these

http://www.mcmaster.com/#ball-and-rolle ... gs/=b7g4we

if you click on ball and roller and then on roller, there are several types- spherical, cylindrical, tapered and needle.

I'm going to guess that some type of roller bearing would be best, as they seem to be the "quickest" but am looking for a recommendation on the type of bearing that would best. This wont have much of a radial load, and the shaft diameter will be either 1/4" or 5/16".

What type of bearing would you recommend?

Thanks all

[youtube][/youtube]

Posted: Sat Feb 26, 2011 7:11 pm
by Jimmy K
A wet roller bearing would be best for that, although they are by no means the best bearing available. Turbochargers use oil film bearings, whose coefficients of friction are remarkably low, and considerably lower than those of roller bearings. You can find smaller versions of these in hard drives if you're interested:

http://en.wikipedia.org/wiki/Fluid_bearing

I don't think you would want anything less than a roller bearing. Ball bearings tend to allow more side and torsional play than most people would like.

Posted: Sat Feb 26, 2011 7:25 pm
by jrrdw
Needle Bearing. The smaller needle and more of them the better.

Posted: Sat Feb 26, 2011 7:33 pm
by motorfixer1
Without going the jewled sleeve bearing route a high quality needle bearing should suit your application just fine. Maybe some felt washer material on the shaft on either side of the bearing would be nice also. Neat project by the way!

Posted: Sat Feb 26, 2011 8:22 pm
by JDP12
thats what I thought.. needle bearing.

When selecting one on mcmaster, would you select one rated for the highest RPM possible? Seems like that would make it the best as far as frictionless--
AKA a 60,000 rpm rated one would be better than a 7,000 RPM one?

obviously they wouldn't be going that fast, but does my logic make sense?

Posted: Sat Feb 26, 2011 9:46 pm
by Crna Legija
i would say the rating is its max rpm

Posted: Sat Feb 26, 2011 10:35 pm
by jamie e
what about some good old skateboard bearings, cheep and effective. if you want high quality you could get some ceramic bearings which are lighter than standard bearings and don't rust like steel.

Posted: Sun Feb 27, 2011 4:27 am
by JDP12
yea they are nice, but can get expensive, and i'm afraid they are gonna be too big for the small size necessary

EDIT: Did some quick lookin around- looks like they can be had for $13.95, not bad.

anyone else have thoughts on the skateboard bearings ideas? And the dimensions of them-- ID and OD, and thickness?

Posted: Sun Feb 27, 2011 9:42 am
by SpudFarm
http://www.vxb.com/page/bearings/CTGY/I ... le-Bearing

You might find what you need on that site.

Posted: Sun Feb 27, 2011 10:25 am
by Technician1002
Skateboard wheels are designed for a substantial load with considerable side thrust. Due to the spherical balls and contact areas at differing diameters in the races, they increase friction somewhat with loading. (side scrubbing on the balls)

Needle bearings are another type of high load bearing and they hold up to even higher loads without a high degree of friction increase. These are often used in high RPM applications with high load forces and low side thrust. Common uses for these bearings include chainsaw engines and the like.

The sleeve bearings are low load bearings for items such as fans and other applications with low dynamic and static loads.

A low friction bearing that trades the efficiency of needle bearings with the side thrust advantages of ball bearings with high load abilities are tapered needle bearings used in pairs. A common place you find these are car wheel bearings and airplane engines due to the high loads these bearings need to support.


The fly reel does not have high end thrust or high load demands so a sleeve or ball bearing would work fine.

Posted: Sun Feb 27, 2011 10:41 am
by Crna Legija
Technician1002 wrote:Skateboard wheels are designed for a substantial load with considerable side thrust. Due to the spherical balls and contact areas at differing diameters in the races, they increase friction somewhat with loading. (side scrubbing on the balls)
Needle bearings are another type of high load bearing and they hold up to even higher loads without a high degree of friction increase. These are often used in high RPM applications with high load forces and low side thrust. Common uses for these bearings include chainsaw engines and the like.

The sleeve bearings are low load bearings for items such as fans and other applications with low dynamic and static loads.

A low friction bearing that trades the efficiency of needle bearings with the side thrust advantages of ball bearings with high load abilities are tapered needle bearings used in pairs. A common place you find these are car wheel bearings and airplane engines due to the high loads these bearings need to support.


The fly reel does not have high end thrust or high load demands so a sleeve or ball bearing would work fine.
Cant wait to see what jsr has to say about that :D

Posted: Sun Feb 27, 2011 10:56 am
by Technician1002
Probably the same type of things he says for male and female pipe fittings and how threaded fittings are assembled. :roll:

Posted: Sun Feb 27, 2011 12:49 pm
by JDP12
so Tech - you're basically saying that a normal needle bearing should be sufficient?

EDIT: for those of you interested, here's a detail of the bearing I'm thinking of getting for this project.

EDIT 2: I think I might order a ball bearing and a needle bearing, just to be able to test them both out, since I don't really know how well they'll perform

Posted: Sun Feb 27, 2011 5:48 pm
by Technician1002
Due to the large rollers and resulting surface area, that bearing is designed to handle high loads. With the carrier shown and the viscosity of the lubricant, the bearing has a fair amount of friction, so it won't free spin nearly as well as dry skate wheels.

A small contact area bearing (Ball Bearings) will have much lower friction under light loads. Under heavy loads the roller bearings will have a much larger contact area to support the load with lower piint contact area distortion and losses. With a high load, the roller bearings will have less loss.

Sleeve bearings are generally used in low loading applications such as fans as the friction and wear goes up with loading.

I guess at this point is what size load are you needing to support? Will contamination be an issue? Open ball bearings in skate wheels shed dirt as the bearing race can eject dirt. Roller bearings due to the shape are much poorer at pushing dirt aside and work best when sealed away from dirt.

Posted: Sun Feb 27, 2011 6:25 pm
by JDP12
ok,

the load would only be the load from a fish up to say 10lbs, max, and it wouldn't be direct, since its going through a rod as well.

so ball bearings are actually the better option here? that makes sense, less contact.

also, there are two types of bearings available- ones with steel balls, and ones with delrin balls. McMaster states that the delrin ones are smoother