Seriously, it will be as precise as any high-end stand. We'll take an inexpensive but solid Performance Spin Doctor truing stand and add threaded indicators to make it much more effective - faster to use, more durable, and light-years more precise - for less than $7.
Step 1: Our Base: the Performance House Brand Spin Doctor II Truing Stand
This guy is always "on sale" at performancebike.com. As I write this it is $49.99, but I have seen it as low as $39.99 occasionally.
In addition, there are lots of ways to get it cheaper. Personally, I think I got it for $49.99 - 20% off offer - 10% Team performance + free shipping offer, so about $36, which is why I say that this project can be done for well under fifty bucks.
First of all, Performance basically always has at least a 10% discount code around. Check out bikeforums.net in the coupon forum - you'll often be able to get or ask for the latest one. Also, Performance regularly offers free shipping, so you can get on their e-mail list and keep an eye out for that and other offers. If you happen to live near a Performance you can also have it shipped to the store for free. You will have to pay sales tax, but if you live near a store you will probably have to pay tax on an internet order to your house, too. Finally, if you buy bike stuff regularly, it may worth it to pay to be a Team Performance member, where you get 10% back in points to use towards other stuff, plus faster shipping.
I am not connected to Performance Bike in any way. I just happened to buy this particular stand for myself, and this instructable uses it as an example for modification. You may find other inexpensive stands on the market and be able to do similar modifications. I personally haven't seen one that is of this quality for less, however.
Clearly if you're handy you could try to make a stand from wood, metal, plastic, whatever, and add threaded bolts in a similar fashion.
There are two reasons this will be tough, however, and may make buying a pre-made stand worthwhile:
1. Different wheels have different axle lengths, and your stand will need to adjust for those differences and still remain rock-solid.
2. Most wheels with quick-release hubs are actually not fully tightened to the bearings until the quick-release is clamped down. That is, if the quick release is not tightly clamped onto the wheel hub, the wheel actually has a little extra play in it, and this will affect how true you can make your wheel. So your homemade truing stand will have to allow for this solid clamping and still remain rock-solid. You can't just rest the wheel in some slots and go at it. Well, you can, but don't expect to be able to get really tight tolerances.
(I am using a pic grabbed from the Performance website without their permission. I suppose this instructable may drive some traffic their way however, so I doubt they'll mind.)
Step 2: Seven Bucks Worth of Extra Materials
This is all you need:
Three bolts at least three inches long. The size I have used (that fit as well as I can imagine) is
"#10-24 x 4 inches" ($1.20 at my local hardware store)
Six nuts to fit said bolts (#10-24 in this case) ($0.30)
One small hand clamp ($3.00 at the hardware store). These really clamp down amazingly hard. Get the smallest one you can find that will work, so that the weight doesn't pull it away from the rim when in use (and of course smaller = cheaper). The one I'm using is 4" long.
Super Glue ($3.50, but don't you have some in a drawer somewhere?). If you feel chintzy using Super Glue, you can use industrial strength JB Weld or similar epoxy, but the super glue has been plenty solid on my prototype, plus you can use the stand right away.
A pair of pliers (everybody has some...right?).
File or dremel grinder for rounding the tips of the bolts (optional)
Step 3: Remove the Original Lateral Indicators
The original lateral indicators are simply metal dowels that are held in place by rubber o-rings that allow some resistance and hold the indicators firmly. This system is functional but imprecise and frustrating, since when you are trying to move them a tiny distance to just barely touch the rim you end up either pushing too far or not moving them all!
To remove them, simply grab ahold of the plastic tips with pliers and pull them off, then pull the indicators out the other end. You may find that another set of pliers to grasp the other end is helpful if you have them available, but they should not be necessary.
Step 4: Optional: Remove O-rings
It is not necessary to remove the rubber o-rings with the bolt size I have listed, but if you want to - or if you need to use a larger bolt than I have suggested - just use a small screwdriver or other tool to push out the brass insert that holds them. You will need to push pretty hard, and you will need to put the brass insert back in before moving on!
Step 5: Install the First Nut
If you have removed the brass insert, put it back in.
Now you will simply super-glue (or J-B Weld, or whatever) the first nut to the outside of the brass insert - the 10-24 nut I have used actually fits pretty much perfectly within the plastic circle. Be careful to use as little glue as necessary to get a good bond, and do not let it block or gum up the threads in any way! (and if you do get a little messy, remember that fingernail polish remover removes super glue).
Note that the screw hangs a bit after install, which is why we'll add another nut or other support in the next step.
Step 6: Add Another Nut (or Other Support)
Now we'll add another nut on the outside.
Three key points:
1. Put the nut most of the way onto the bolt, then add a bit of glue and back the bolt up to bring the nut/glue to touch the plastic. This way the threading will match for both nuts.
2. Once again, be careful to use as little glue as necessary for a good bond, and avoid getting any on the the threads of the bolt or nut.
3. Back the bolt up only enough to touch glue to plastic. If you "squeeze" it onto the plastic, the threading of the two nuts may be slightly mismatched and make it more difficult to turn the bolt.
Note that an actual nut is not necessary since there is already threading on the first nut. If you can find a washer with the perfect-sized hole to fit the bolt, that would work as well, and maybe even be preferable, because variations in the bolt threading could result in a mismatch of threading between two bolts spaced an inch apart. One option: drill into the second nut with a drill bit just thick enough to eliminate the threading.
That said, I used two threaded nuts on mine and have had no problems.
Step 7: Repeat for the Other Side
Uh...yeah. Hopefully pretty straightforward.
Step 8: Add a Comfy "knob" With Whatever You Like
The screw heads are small and no fun to turn over and over, but it's easy to super-glue on something more comfortable. Use pennies, washers, half a superball, a medicine bottle top, whatever you have handy.
Keep in mind that the larger the diameter of your knob, the more precise your movement of the indicator can be. If you really want to be able to move the indicator just a hair's breadth, a bigger diameter knob is the answer (but it will also take longer to move wide distances).
I found the original knobs to be pretty comfy. They were both screwed and glued onto the metal dowel, so I clamped them down hard in a vise and unscrewed the knob with pliers.
Note: if you choose to use pennies or other currency, please be aware that it will increase the cost of this project. Of course, you can get a refund any time you like...
Step 9: Adding a Roundness Indicator.
The Spin Doctor stand supposedly has a roundness indicator, but it's pretty worthless. It's impossible to move it small distances, and it is wide enough to touch both edges of the rim. It's also next to impossible to keep it accurately pressed against the rim to find dips.
We will just add one screw onto the original roundness indicator. Note that it is preferable to have a roundness indicator that just touches one side of the rim. It is impossible for a rim to be perfectly even on both sides of the rim, so trying to touch both sides at once is both confusing and inaccurate. By making one edge perfectly round, the other with be as round as possible as well.
The first step is simply to put two nuts on our third bolt, about an inch apart.
Step 10: Clamp on the Roundess Indicator.
Next we simply clamp the bolt on. Be sure to use the smallest clamp you can find so the weight of it won't pull the indicator down.
I originally thought to simply super-glue this on, too, but I realized that it wouldn't be adjustable for different rim widths. Thus the clamp, which allows you to move the indicator to suit any wheel. And believe me, this little clamp is plenty strong enough to hold the bolt solidly.
Note that you can adjust this setup to any angle. It doesn't have to point straight up and down, as long as the tip of the indicator can touch edge of the rim.
Step 11: Optional But Recommended: File the Bolt Tips or Add a Buffer
The bolt tips have sharp edges, so it's advisable to round them off, either with a file or a grinder.
Alternatively, you can buy little nylon caps at your hardware store, or put a drop of J-B weld on the tip of each.
I personally plan to grind mine with a dremel because I like the clear sound of metal-on-metal when I'm truing a wheel.
I'll add a pic when I get it done.
Step 12: The Finished Product
So there you have it, an on-the-cheap truing stand that is precise down to fractions of millimeters, using metal parts that should last and last, and easy to overhaul if for some unknown reason you need to.
Step 13: Final Thoughts
Some final thoughts:
There is another instructable that uses a dial gauge and a similar inexpensive stand. That instructable actually inspired me to consider modifying my own! But do you really need a dial gauge? From my perspective the answer is "no". Just buy a cheap set of "feeler gauges" that include 0.2mm and 0.5mm sizes. With the precision of the screws we've installed, you can insert a feeler gauge between the indicator and the rim. Then spin the rim. If it doesn't touch the entire way around, your wheel is true to that maximum error.
If you want it to look mildly prettier, you could conceivably file/dremel the edges off of the "second" nut and insert it into the plastic, then press the brass insert in over it.
Opinions and suggestions on this guy are welcome!