Static Balancing Ways?

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brucepts
Posts: 39
Joined: Sat Jan 04, 2003 7:25 pm
Location: Lancaster County PA

Static Balancing Ways?

Post by brucepts »

Has anyone every made their own? I'd like to make something up to statically balance small engine cranks. Nothing real elaborate just something to start out with and if any benefits are seen maybe go "better" I've looked at pics of them and they don't seem all that complicated to make? I was thinking a nice set of ABEC 5 bearings the size used in inline skates as bearings and make some wheels to fit them in, make the framework from tubing filled with sand to add some mass? Freestanding so its fits under the drill press or set it up so I can bolt it down on the mill to drill the balancing holes? Any ideas?
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Bill_Cook
Posts: 535
Joined: Sat Jan 04, 2003 10:28 pm
Location: Walnut Bottom, PA, USA

Re: Static Balancing Ways?

Post by Bill_Cook »

How about "knife" edges?
Drop on convience.
The crank can be turned end for end to average if nessesary.
I use the tops of my lathe's V ways to check the ballance of surface grinder wheels and other odds and ends that fit.

bc
BC

If there was only one way to do each machining job, the smell of sulphurized cutting oil smoke would have fewer fond memories.
jpfalt
Posts: 982
Joined: Sun Jan 05, 2003 12:55 pm

Re: Static Balancing Ways?

Post by jpfalt »

Making a balancer with wheels is not dificult, however you will want to use ball bearings without seals as the seals will drag and prevent the wheels from turning freely. If you can find shielded bearings that don't drag, go with those. You will also want to clean grease out of the bearings, again to reduce drag. Concentricity of the wheels on the axle through the ball bearing is critical. You will want concentricity to be within about .0002" TIR.

Rather than making a bolt down unit, you will probably want to make it three legged with two of the legs adjustable so that you can level it on a bench or table.

The same is true if you choose to make a blade type balancer. Then levelling is most critical. getting the top surface of the rails level and straight within .0002" is also critical.
gmacoffline

Re: Static Balancing Ways?

Post by gmacoffline »

knife edges are cheaper, and usually easier to make or get in some form ( a matched pair of surface ground edges on a piece of hard plate held in clamps will do it if you level them properly, you can get an economical set of angle blocks and make a set from them quite easily, secure a piece of hardened steel to the top of each and bevel grind them to a parallel knife edge on a surface grinder.) , easier to set up if you have a flat area, and easier to store. rolling centers of whatever type are great if you have time to build them and set them up correctly, and if you have space on a machine to use them. the rolling types always have some friction so if you are looking at small balance differences, a pair of hard knife edges may get you the desired sensitivity with a lot less work and trouble. if you can get jeweled bearings readily, these are fine for lighter weight items but there are substantial efforts involved in aligning them concentrically to your part.
brucepts
Posts: 39
Joined: Sat Jan 04, 2003 7:25 pm
Location: Lancaster County PA

Re: Static Balancing Ways?

Post by brucepts »

Bringing kind of an old post current but I wanted to say thanks to all who helped me with their posts. Here are some pics of what I came up with, its not finished yet and needs some work but it gives you an idea of what I'm going for. I made it so it sits on the end of my big ole hendey lathe so it has a stable level base support. The uprights are adjustable for different items I want to balance, I plan on using this to balance rotating assemblies I make, clutch disks, flywheels etc. I'm working on a set of bob weights now for my crankshafts.

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