Wheelbuilding / Wheel Building / Wheel build help

I also have a spoke threader question. This is for the more experienced / pro builders here who may have pondered the same question. I've been pondering this question for a few months and still can't decide. I'm looking at purchasing the Morizumi SCT but it's pricey. After I pay the import tax which will be around £500 it'll come to about £2,500 ish. It's one of the best out there but I'm not sure I can justify such a layout given the size of my business. But when it does peak it would certainly come in handy rather than ordering from various suppliers and seeing what lengths they have in stock.

http://www.wheelfanatyk.com/store/morizumi-sct-machine/

Would certainly make life easier when I have loads of builds on the go. I can use up all those lengths that sit around waiting for the build that doesn't happen. I can also buy up cheap stocks of spokes and cut them to the length I need. I can also supply custom lengths. But how long till I break even?

Any thoughts appreciated.

This is for the more experienced / pro builders...

IANA^, but you could either reduce your initial outlay with a joint purchase (any one else local); or increase the rate of return by offering a a threading service to other builders (could be done by mail).

The former would have a more immediate impact on your bottom line, but joint-ownership can be complicated; cutting spokes for others will take longer to pay you back, but would be an extra source of income for as long as you want it to be.

I'd think it would be easier to find people who want spokes cut, than for whom joint-ownership of the machine would be a practical proposition.

Thanks for that. I do have some spare cash at the moment so thought it might be a good long term investment. I could easily at a page to my website about a spoke cutting and threading service. If I charged 20p per spoke I would break even at around 12,500 spokes. But the main attraction is that there wouldn't be any bottleneck of waiting for spokes to arrive during an order and I could turn them around much faster.

If you'll find your work process more lean + inspiring + enjoyable with the new machine then 2.500£ is dirt cheap.

£2500 is about what I pay over 3 years to have the nicer and more efficient e-Hdi 90 engine and ETG6 gearbox compared with the base 75PS/5-speed manual. In pure cash terms, it doesn't make sense (only saves about £1000 in fuel), but it's £10 a week net well spent to have a much more pleasant experience at work. Your investment is over a much longer term, so less per week, and may even make you money.

Also, tool porn.

Tool porn is indeed a great motivating factor. Working with a good tool certainly is a pleasure. I've certainly found that with the P & K Lie truing stand which again I deliberated upon for weeks before finally making a purchase. OK, I don't think I need much more convincing. Thanks again for the input.

I did consider a Morizumi machine, but the trend is for spokes where the butting starts at the end of the thread and cannot be shortened. Think about Sapim D-Light, which is an excellent spoke, better and stiffer than Laser for a very similar weight. You can't cut/thread it... so in the long run these machine might become useless

I bought some tange hubs and hplusson rims (ERD 557) and I was hoping to lace them up with some dt Swiss bladed spokes In a two cross pattern, but I can't find any way of calculating the spoke sizes (due to the hub's irregular spoke hole pattern) the only way I could see is just trial and error with some oversized spokes, but knowing me I'd screw that up far too easily. Any advice?

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There is at least one calculator online that does paired holes hubs... if only I remembered which one... :-/

http://www.ebikes.ca/tools/spoke-calc.html

check the 'paired holes' option and measure the distance between them.

I don't know how reliable this calculator is however so don't blame me if it's wrong!

Any advice?

Draw the 3 polygons (two irregular decagons for the hub and an icosagon for the spoke holes in the rim) in Sketchup, then draw lines joining the relevant points and see how long they are. You can also do it with trigonometry, since you know the positions in a 3-dimensional Cartesian space of the two ends of the spoke. Jobst's book has the formulae and corrections needed for real spokes, you'll obviously need to adapt them slightly to allow for the spoke holes not being equispaced on their pcd.

Is there a market for spoke cutting? I know JRA have a Phil Wood machine and sell spokes in any length, but they don't charge more because they are cut to length.

Yes, it reduces the number of sizes you need to stock... if you used only plain gauge to virtually only one length needed, but realistically these days you need double butted, so you still need 5 mm increments. Some spokes cannot be cut (as above D-Light, but also Alpine 3 I think)... I don't know if it ever pays for itself. it is a nice piece of kit and tools are an investment... besides, if you do it as a business you can write it off your tax, which is a win win situation if you are not desperate for cash.
I would still not buy it though... I believe in the long run they are getting obsolete

Draw the 3 polygons (two irregular decagons for the hub and an icosagon for the spoke holes in the rim) in Sketchup, then draw lines joining the relevant points and see how long they are. You can also do it with trigonometry, since you know the positions in a 3-dimensional Cartesian space of the two ends of the spoke. Jobst's book has the formulae and corrections needed for real spokes, you'll obviously need to adapt them slightly to allow for the spoke holes not being equispaced on their pcd................. PARKLIFE

Has anyone seen/tried this?

Acoustic tension tuning has been discussed, including that app, although I can't remember whether the app was mentioned in this thread.

thanks, this is the best i've seen yet, looks hopeful

thanks, i'll use this method if bmx_fred's spoke calculator doesn't work, thanks for the help.

I did UTFS using the URL but nothing showed up. What's the verdict on acoustic tension tuning?

What's the verdict on acoustic tension tuning?

It's not without its own problems, but it has the potential to be cheaper for a given level of accuracy and precision than the more common load/deflection method because frequency measurement electronics are much cheaper than load cells. The problems are 1. You need to have a good model of the spoke to translate resonant frequency into absolute tension and 2. spokes which touch at the crossing might not be resonating at the fundamental frequency of their full length, they are effectively stopped (think guitar fret) at the crossing, or they might be vibrating like something which has another spoke attached to it at the crossing point. Acoustic tuning therefore works best in a factory where you're building a lot of the same design of wheel; you build the prototype using a very expensive load cell, then measure the dominant resonance of the spokes on that wheel and issue the tuning to each building station for replication using cheap frequency analysers.

For home builders, acoustic tuning can probably get your relative tensions more closely matched than a cheap tension meter (and will certainly be faster), if you have even a modest ear for harmony, but you'll probably still want the tension meter for absolute tension.

I'm sure @ugosantalucia has had his say on the issue before, and may wish to take issue with me again :-)

Yep, I use a Park tension meter to get the spokes to roughly the right tension, and then ping them to make sure they're all the same (or as near as possible). Maybe it's just my classical musical training (natch) but I find that I get detect tension differences by ear which don't show up on the TM1.

Au contraire.... I agree with everything.
In principle it is a better way to measure tension, but in practice I suspect any app will be largely inaccurate due to the above reasons (length of the free spoke, gauge, taper etc...). The beauty of the three point bending method is that it is relatively simple to use, it can be calibrated for accuracy, it is very reproducible and the tool is robust and compatible with workshop use.

At Easton they use acoustic probes to measure tensions and generally their wheels are well tensioned. They are still crap though, mainly due to terrible hub/spoke interface design

I'm about to start stripping down my Zipp 404 Firecrest wheel so I can replace the god-awful POS Zipp hub with a Tune Mag170. Apparently the Mag170 doesn't have the creaking issues the Mag180 did. Here's hoping.

Anyway, I'm going to build them up 2x on both DS and NDS, unlike the current setup which is 2x NDS and radial DS. On the DS I'll definitely be using CX-Rays but was considering using Super CX-Rays on the NDS. Apart from the cost of the Super spokes, and taking as read the fact that any weight saving is negligible, is there any reason why this would be a bad idea?

Couple of points

1) I hope you are aware Zipp rims are fitted with oval rim washers, that need to be removed and replaced with new (non deformed) ones... it is a royal PITA

2) Sapim CX Ray is already a flimsy spoke, I would not use anything lighter... too fragile to handle and will most likely fail quite rapidly and will have lower stiffness.

3) For a bit of advice, this is my rebuild of a 303 on a Dura Ace hub, if that helps
http://whosatthewheel.com/2014/12/27/zipp-188-hub-and-a-firecrest-rebuild/

Apparently the mag170 does still have problems, there's a big old thread on WW's with complaints, a dt swiss 240s or WI t11 might be a better/more durable replacement

(1) I am, I have a packet of 100 Zipp nipple washers ready and waiting to be used.
(2) Flimsy? Not in my experience. 28 spokes front and rear on my 29er MTB, and they've happily held up through crashes which have left me struggling to walk away.
(3) Yep, read it. Thanks. Seems pretty straightforward.