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Trike Lover
10-22-2011, 12:22 AM
I've been giving some thought to a simple jig that would allow builders to drill their spoke holes spaced evenly around the 1/8" thick steel hub plates, of whatever diameter, without using paper templates.

I have the glimmerings of an idea. The object is a simple drilling jig that would give spoke holes even spacing from the flange edge, and even spacing around the disc.

If I haven't dropped a decimal point or lost too many brain cells, such a drilling jig design would:

- be simple to make from scrap steel,
- have only a few pieces,
- be adjustable for various spoke numbers, eg. 16, 18, 24, etc. holes per flange,
- be adjustable for various flange diameters, and
- keep the spoke hole spacing from the rim edge even.

From the drawings and photos in the various sets of plans I have, it looks like about 1 drill diameter, i.e. about 3/32" is the minimum amount of "meat" wanted between the spoke hole outside edges and the hub flange edge. A bit more probably wouldn't hurt.

What's the ideal spacing ?

Is a drilling circle about 1/8" in from the edge enough, or would having the spoke holes set a little further in from the rim of the hub flange - maybe 3/16" - produce a stronger overall piece?

Anyone have some thoughts on this? I'd like to fix the optimum rim edge spacing before I go any further. Any input would be appreciated.

David_s
10-22-2011, 12:32 AM
I can think of 1 that only has 3 parts.
A plate that gets mounted to the drill press.
A center peg to rotate the piece on.
A guide pin, this is the same size as the hole you are going to drill for the spokes but offset from the drilling point 1 spoke angle.

Remove the guide pin.
Mount plate to drill press and align manually for the first hole.
Place blank hub over the center pin.
Drill the first spoke hole.
Rotate the hub blank until fresh hole is over the guide pin hole.
Place guide pin though hole in hub blank and into jig.

Now you can just drill the next spoke hole lift the blank up off the guide pin rotate and drill the next hole. This way the last hole drilled will always fit on top of the guide pin until all holes are drilled.

Of course you would need a different jig for different amount of holes.

As far as how far from the edge I would just measure some existing hub.

Odd Man Out
10-22-2011, 01:17 AM
Ideal space from spoke hole to hub rim is width of spoke hole. So I use 2.2mm drill bit for spoke hole -- 2.2mm spacing from edge of spoke hole to edge of hub.

socialtalker
10-22-2011, 08:04 AM
definately subscribing to this thread...lol.

Odd Man Out
10-22-2011, 02:02 PM
Is a drilling circle about 1/8" in from the edge enough, or would having the spoke holes set a little further in from the rim of the hub flange - maybe 3/16" - produce a stronger overall piece?

Anyone have some thoughts on this? I'd like to fix the optimum rim edge spacing before I go any further. Any input would be appreciated.

More space is not better because when you have more space you have more space for metal on the spokes to grind on metal of the hub flange. Gotta remember that the spokes are always moving around (microscopically) when the wheel is turning. Also, if you have laced a wheel, think about how the spokes are "bent" over the hub flange to get to the nipple -- putting the spoke hole further into the hub creates more of a stress bend. That equals undue stress on the spokes and contributes to increased wear and shortened lifespan.

Radical Brad
10-22-2011, 08:25 PM
Another thing to consider is that the spoke is not pulling right into the thin part of the flange due to the angle it leaves the flange. On a radial laced wheel, this becomes more important. Also, aluminum will have much less strength than steel.

Brad

Trike Lover
10-22-2011, 08:55 PM
I can think of 1 that only has 3 parts.
A plate that gets mounted to the drill press.
A center peg to rotate the piece on.
A guide pin, this is the same size as the hole you are going to drill for the spokes but offset from the drilling point 1 spoke angle.

Remove the guide pin.
Mount plate to drill press and align manually for the first hole.
Place blank hub over the center pin.
Drill the first spoke hole.
Rotate the hub blank until fresh hole is over the guide pin hole.
Place guide pin though hole in hub blank and into jig.

Now you can just drill the next spoke hole lift the blank up off the guide pin rotate and drill the next hole. This way the last hole drilled will always fit on top of the guide pin until all holes are drilled.

Of course you would need a different jig for different amount of holes.

As far as how far from the edge I would just measure some existing hub.

Sure, for anyone who has a drill press, it's the obvious method.

You've described exactly one of the two different jig ideas I had, and that I'm sure others have thought of and used. What I'm adding is is built-in angle selection (so that you can set 18 or 24 holes) without using a rotating table & chuck, or a paper template.

The other jig is meant for use without a drill press. It also indexes by one hole using a pin in the previous hole, with the option of selecting angle to give you 18 or 24 hole flanges. evenly spaced. It also maintains the optimum distance for the spoke holes from the flange edge. The other variable is the diameter of the flange blank itself.

Enough people have mentioned trouble getting uniform results using a glue-on template and freehand drill that I thought it would be worthwhile to try and cobble up an alternative method.

TL

Trike Lover
10-22-2011, 08:58 PM
Ideal space from spoke hole to hub rim is width of spoke hole. So I use 2.2mm drill bit for spoke hole -- 2.2mm spacing from edge of spoke hole to edge of hub.

That's how I made mine also - a 3/32" hole with 3/32" from the edge of the spoke hole to the edge of the hub. The end results were a long way from being even, either from the edge or from spoke hole to spoke hole. I think Socialtalker has mentioned similar issues.

That's what got me thinking about some kind of guide or jig, anyhow.

Trike Lover
10-22-2011, 09:09 PM
Another thing to consider is that the spoke is not pulling right into the thin part of the flange due to the angle it leaves the flange. On a radial laced wheel, this becomes more important. Also, aluminum will have much less strength than steel.

Brad

Both good points, Brad. I know with a 3-cross 36 spoke rim the spokes come off the rim at a considerable angle. Hadn't thought about radial lacing, though - that's a whole other can of worms.

Aluminum presents a problem because, as **** *** says,

"More space is not better because when you have more space you have more space for metal on the spokes to grind on metal of the hub flange. Gotta remember that the spokes are always moving around (microscopically) when the wheel is turning. Also, if you have laced a wheel, think about how the spokes are "bent" over the hub flange to get to the nipple -- putting the spoke hole further into the hub creates more of a stress bend."

Aluminum is not only weaker for a given cross-section - certain soft alloys "flow" under stress. I haven't got any high-end aluminum hubs to check as examples. If I can make a repeatable drill-press-free jig for steel hubs, a person using aluminum for hub plates might have to use different dimensions.

TL

Trike Lover
10-22-2011, 10:53 PM
Ideal space from spoke hole to hub rim is width of spoke hole. So I use 2.2mm drill bit for spoke hole -- 2.2mm spacing from edge of spoke hole to edge of hub.

Working this backwards and comparing your 2.2mm to my 3/32", the 2.2mm drill bit and 2.2mm from spoke hole edge to rim is within 0.00875" (0.22 mm) of using a 3/32" drill bit with 3/32" spacing from edge of spoke hole to edge of hub.

In either case, the centerline of the circle of drilled holes is 1/8" ( 3.2 mm) inside the edge of the hub. So we get very, very close the same answer.

Guess that's what I'll go with.