Work in progress.
This project was developed for Eric Thompson of Walrus Wheel Works.
Based on the Noble lacing jig & a few other lacing jigs.
I'm told Noble will no longer be selling these.
It boasts compatibility for the following rim sizes, & everything between.
- 18 in / 400 mm ISO
- 20 in / 406 mm ISO
- 24 in / 547 mm ISO
- 26 in / 559 mm ISO
- 27.5 in / 584 mm ISO
- 700c / 29 in / 622 mm ISO
Adapters are included for use with the following hub axle standards.
- 12, 15, & 20 mm thru-axle
- 5 mm quick release
All common hub OLDs should be supported up to 148 mm Boost. I believe the jig may be able to support 12 x 197 mm hub axles too.
The max length of spokes that can hang freely from the hub support depends on the flange to locknut distance - it's about 300 mm, which should cover some of the longest spokes. Of course, you could boost this yourself by lengthening the hub upright.
The design was intended to optimize:
- portability: (dis)assembly time should be quick
- cost: no costly, exclusive tools (machining) or materials
- flexibility: COTS (common off-the-shelf) components can be readily swapped out, requiring only a handful of changes in CAD to make the necessary adjustments. The CAD is one of the most complete assemblies I've ever done. A master skeleton sketch drives most of the children component geometries, making it trivial to add flexibility to the design.
The end cost is about $60-80 depending on sources.
In a few cases, I didn't order the minimum quantity necessary to complete the project, but bought kits or redundant multiples. It adds to the cost, but those items can be used for future projects. If you made no mistakes & have no plans to use the excess items, the true cost of the project could be much lower.
I accidentally deleted my bookmarks for the various wheel models. I can't trace them easily anymore, but I found them on GrabCad.
Here are the COTS (common off-the-shelf) components that greatly simplify the design.
Many components were sourced from overseas, so the shipping took quite some time.
In a few cases, I didn't order the minimum quantity necessary to complete the project, but bought kits or redundant multiples. It adds to the cost, but those items can be used for future projects. If you made no mistakes & have no plans to use the excess items, the true cost of the project could be reduced.
Regarding purchasing from 80/20: it's only really the single source for the custom-cut 3030 extrusion. You might as well buy all of the 80/20 parts from 80/20 since they control the price very well on the internet, & lump the shipping together.
However, if you, like me, made mistakes & had to make several separate 80/20 orders, there's no reason to buy from 80/20 anymore since their flat rate shipping is about $14-15 regardless of what you order. In that case, 80/20 maintains an eBay presence (links below) which offers far more reasonable shipping rates.
626ZZ bearings: 6 mm ID, 19 mm OD, 6 mm thickness.
This listing is for 10 bearings (allowing for mistakes) & cost only $3.99 with free shipping.
Chosen for economy, availability & M6 clearance.
It's easy to press these in crooked & damage the bearing. Ordering 10 was the correct amount.
In retrospect, these bearings have a tad too much play in them. It's serviceable, but disappointing in practice. I may seek out alternatives.
The uprights are based on threaded rod as spines or backbones, & rely on any sort of a hollow tube as a spacer to confer rigidity & a rapid & inexpensive way to get height. The possibilities are numerous.
Eric wanted a neater end result, so we opted for some very overkill aluminum tubing (33.24 mm OD, 26.66 mm ID = 1.31" OD, 1.05" ID).
Over the months I spent developing this, I found plenty of other candidates (especially in dumpsters) - more if you're willing to have mismatched uprights:
- suspension fork stanchions
- old flat handlebars
- seatposts: some random ones I found have an ovalized interior, would could make this problematic
- broom/mop handles
- random structural framing for exercise equipment or most anything
- PVC tubing
- use your imagination
In short, you can get these for free.
I don't recall how much we spent on buying this aluminum tubing.
Tip: use a sharp pipe cutter for clean cuts.
DIN 472 22 mm internal retaining rings
DIN 472 22 mm internal retaining rings
I bought a kit because I envision using these more in the future. $9.74 for all this:
- 8.0mm 25pcs
- 10.0mm 25pcs
- 12.0mm 25pcs
- 14.0mm 25pcs
- 16.0mm 25pcs
- 18.0mm 25pcs
- 20.0mm 25pcs
- 22.0mm 25pcs
- 26.0mm 20pcs
- 28.0mm 15pcs
Again, you could do this more cheaply if you just wanted three 22 mm snap rings.
I used DIN 472 because of economy & availability.
M6 Roll-In T-Nut with Ball Spring
They worked, but didn't self-align.
Here are other viable (I think) candidates. I'm not quite sure what the difference is between them. You want the self-aligning section to match the width of the extrusion where it engages, which is 8 mm for 30 x 30 mm extrusion.
The ball spring & self-alignment greatly improve the ease of (dis)assembly.
The 3668 part was $2.55/each.
17 Mar 19 update: I now only recommend this one 13031 M6 Self-Aligning Roll-in T-Nut with Ball Spring. It has much better self-aligning properties & fit.
I bought these from this eBay listing here for $1.60/each.
M6 Double Slide-in Economy T-Nut
3030 extrusion. One of the most expensive components here.
You can definitely swap this extrusion out for different sizes as long as you make the change in the CAD. Many (3D printed) parts are based on a 30 x 30 mm extrusion size.
You will also need to swap out some 80/20 hardware to match.
It made more sense to stick with metric than English sizing.
30 x 30 mm extrusion takes an M6 fastener size, & the ends can be tapped to M8 x 1.25 (you can have 80/20 do this for a fee). The threaded ends allow you to attach the three extrusions to the center brace with 3 bolts instead of 6 (see the center brace section for more detail) - it's not necessary.
You can order custom cut lengths through 80/20 but not McMaster.
I ordered the extrusions cut to 330 mm, which is nearly the minimum to accommodate the largest common rim ISO diameter: 700c = 622 mm = 29" rims. This is about 12.992", which means stock 12" lengths will not be long enough without tweaking other geometry.
I've had good luck with 80/20 producing good surface finish on the cuts, & keeping them square. They're definitely not hacksaw results.
Cost: $15.20 total with cuts.
3030 end cap
Includes countersunk holes for attaching to the extrusions. There are M8 clearance holes on the bottom if you want to attach using M8 bolts instead. However, this would take more (dis)assembly time since the allen keys would need to be restarted several times to achieve tightening torque (unless you have a ratchet). Furthermore, the bolts need to be completely removed for disassembly, unlike the M6 countersunk bolts on top.
I would boost the infill a lot more in the future.
I'm not terribly satisfied with the interface used for the axle adapters. It results in some fragile parts. I'm open to suggestions. I considered large 3D printed threads, but well defining them in CAD isn't easy.
I considered just slipping sleeves over the central M5 threaded rod, but without any axial retaining feature, they could be annoying if they try & lift off when you remove the hub.
I can think of a number of solutions, but they require more than 3D printing to achieve.
17 Mar 19: the latest revision changed these to simple slide-on/off adapters. The friction is definitely sufficient to not pull off when removing the hub.
My 3D printer develops a slight taper when printing this high, so the parts required reaming with the M5 x 0.8 threaded rod to get a good fit.
These may get loose over time as you cycle through putting them on & taking them off. I don't know how long that will take, but it may not be too bad. It's the simplest solution that works, that I've found so far.
For another revision, I would boost the infill a lot more so they more solidly connect to the extrusion without fear of cracking.
The rim rollers ended up taking a decent press fit with the bearings. They use a diametral step to locate them in one direction along the upright axis, & an internal snap ring for the other.
In practice, the retaining ring is almost certainly not necessary; the friction from the press fit alone is good enough.
Bearings press-fit into the rim rollers can be removed with a 7/32" allen key from the other side.
Make sure you press the bearings in straight. It is somewhat easy to crack the print (at 10% infill) if you're not careful.
A normal 5/16" washer works well to distribute the pressing force across the face of the bearing without crushing the seal (& therefore compromising the bearing's ability to spin freely).
I'm not totally satisfied with the use of an M6 brake pad nut to secure the rim rollers, as it requires some precision in the exposed length of threaded rod, which is not easy to adjust.
We experimented with applying a Plasti-dip spray so rims wouldn't slide on the rollers, but having a rolling contact instead, & therefore preference them to spin on the bearings. However, the friction increased a lot instead.
We are troubleshooting this issue.
17 Mar 19 update: We ended up placing felt discs on the flat horizontal parts. This helps enormously. The problem being that the friction between the rim & the horizontal parts of the rim rollers was enough to seize things. In the future, the rim rollers could be modified so that there is only an edge contact. The horizontal part could be masked off & only the top cylindrical surface sprayed with Plasti-dip.