12mm jackshaft/motor-shaft parts?

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Dec 21, 2007
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12,956
Location
Ft Riley, NE Kansas
I don't know how this will work out, but I would like to collect an index of 12mm bore/shaft accessories like bearings, sprockets (#25, #219, etc), pulleys (5mm-HTD, others?), freewheel adapters, etc.

I have had plenty of hands-on experience with 1/2-inch shafts, which I tried because a few years ago I saw Matt (recumpence) was using those. They work great, and Matt has run 6,000W through them. At the time, Matt had to make his own 1/2-inch shaft-to-FW adapters, but now Staton-inc has started carrying them.

0.500"...1/2 inch
0.472"...12mm
0.394"...10mm
0.375"...3/8 inch

10mm "might be" strong enough for a 1,000W-3,000W jackshaft, but...the 80mm RC motors have a 12mm shaft, and any parts that are made to work for a 12mm jackshaft would be a direct drop-in for the 80mm motors, effectively doubling the potential market, and quickly making the most usable missing adapters cheaply and readily available to all of us.

Thanks in advance for any links/pics...
 
edit: I just recieved a response from Staton-inc customer service, they can provide pilot-bored FW-to-shaft adapters with a 1/4-inch hole in the center, which allows the buyer to bore it out to 12mm. McMaster-Carr is a good supplier of drill bits if you don't have a local supplier of 12mm drills.

Staton-inc has a 1/2-inch bore freewheel (FW) adapter using the most common right-hand (RH) threads. I haven't found a 12mm bore FW adapter yet, but SDP-SI has "bore reducers" (sleeves) that are precisely made, which enlarge a 12mm shaft to 1/2-inch. They are cheap and come in lengths of 12, 16, 19, and 22mm. The FW adapter is 1.100 inch / 26mm long, so it may take two bore reducers to mount it in a stable way.

http://www.staton-inc.com/store/pro..._sprockets_1_10_wide_2_set_screws-1199-9.html
https://sdp-si.com/eStore/Direct.asp?GroupID=273

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VXB is my usual first stop when looking at bearings, I've had good luck with them. The 12mm bore sealed bearings appear to have common outer Diameters (OD) of 18, 21, 24, 28, 30, and 32mm.

$13, 12mm flanged bearing with set-screw, oval back-plate or round. (thanks, speedmd)
http://www.vxb.com/page/bearings/PROD/Kit11697
http://www.vxb.com/page/bearings/PROD/Kit11677
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McMaster-Carr has metric two-piece shaft clamps in 18mm, 24mm, and 30mm ID, so these could be used to mount the bearings above with patricks bearing method. The 24mm aluminum 2-piece clamps are $12/part# 9520T14

http://www.mcmaster.com/#shaft-collars/=ljygql


$13 pressed sheetmetal pillow block housing with setscrew
http://www.vxb.com/page/bearings/PROD/Kit11792
sbpp_fyh_1.jpg


$10 sealed bearing, 30mm OD, 12mm ID http://www.vxb.com/page/bearings/PROD/Kit11234
$15 30mm pillow block http://www.vxb.com/page/bearings/PROD/Kit8293
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$14, 12mm bearing + adjustable housing similar to the GNG jackshaft. The grease fitting is not for the bearings, the bearing slides into a 'sectioned ball' shell that allows the shaft and bearing to change angle as its spinning. For us the grease fitting can be removed.
http://www.vxb.com/page/bearings/PROD/Kit13757
ucfa-bearing-1.jpg
 
SDP-Si has aluminum pulleys for 12mm bore, but only for 15mm wide / HTD-5mm pitch belts, 7 selections from 48T to 72T.
https://sdp-si.com/eStore/Direct.asp?GroupID=346
metalpulley.JPG


Many thanks to ES member "justlooking", he posted a European company that will make a 10T-40T pulley for T5 (what is this?), 25mm long (easy to shorten), and they will bore to 12mm for a small extra charge of 3-Euro. I like the 15T:

http://www.technobotsonline.com/synchroflex-timing-pulley-t5x25mm-15t.html

Heres a link for pulleys with plastic teeth over a metal core, HTD-5mm pitch, 15mm wide, the 14T-22T are available with a 3/8-inch bore (0.375"), might be possible to drill out a tiny bit to 12mm (remove 0.093")? [link also has pulleys up to 90T]

http://torquetrans.com/pulleys/timing-pulleys/5mm.htm

It "may" be possible that the Gates GT2 belts/pulleys would work. I'm sure the belts are fine, it would all hinge on whether the pulleys are easier to find what we want...
 
I've settled on 12mm dia. for my motor and gearbox (input) shafts, too.

12mm hollow linear shafting is handy (hardened on the outer surface only).

eg: https://sdp-si.com/eStore/PartDetail.asp?Opener=Group&PartID=26494&GroupID=352
 
I would also like a 12mm shaft adapter to the 5-hole FW pattern (like ENO and ACS flanged), since there are an increasing selection of 130mm chainring /#219 spiders and #25 sprockets for that pattern. It would look like this $23 5/8-inch shaft adapter from SBP:
http://www.sickbikeparts.com/catalo...ucts_id=158&osCsid=n04bk26faur07rdhaqq2at8334
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Bikemotive, Staton-inc, and Sickbikeparts stock the metal plate spiders for 104, 110, and 130mm BCD chainrings using that 5-hole pattern, so does Staton-inc. I can easily make an aluminum adapter disc, but some people would rather just buy.

m0WKcre20hkhmE91GAmJS5g.jpg


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Thuds 16T freewheel-to-Kart sprocket adapter
http://endless-sphere.com/forums/viewtopic.php?f=28&t=13731&start=50#p215048

12mm shaft spider, accepts 4-hole 104-BCD chainrings and also 5.25-BCD Kart Extron sprockets, like this from deecanio's build:

#219 sprocket suppliers, 4 pages
http://endless-sphere.com/forums/viewtopic.php?f=28&t=12677

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http://endless-sphere.com/forums/viewtopic.php?f=28&t=7992&start=325#p151705
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My most desired parts to have someone start stocking are low tooth-count sprockets and pulleys for #25, #219, and [HTD-5mm, 18T 25mm wide] with only one flange (they can be easily shortened by the buyer to 20mm/15mm).

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I may try to cast a pulley from a silicone mold with a metal core (like SDP-SI pulleys), just for fun (don't wait for me). If it turns out well, I would carry them at cost + 50% and shipping. Its looking like a motor-pulley can be had affordably if we order them with only a pilot hole, and we bore them to 12mm ourselves.

Pic is an 18T, T5 pitch, aluminum, 27mm wide, pilot-bored, from ebay, Ametric corp/americanmetric, $17
$(KGrHqN,!nsFBYtDhFK)BQY,lY79wg~~60_1.JPG
 
SDP-SI has a "taper-lock" with a 12mm bore, and a 17mm OD.
https://sdp-si.com/eStore/PartDetail.asp?Opener=Group&PartID=64659&GroupID=849

As you tighten this down, the ID gets smaller, and the OD gets larger, so this device will clamp a 12mm shaft to a 17mm bored pulley/sprocket. Staton has a 17mm-FW adapter, but due to the short length of the taper-loc, you would need to add a short length of 12mm-17mm sleeve to add length for a stable FW mount.

Biggest drawback is that it is only 18mm long on the engagement portion of the sleeve.
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The "shaftloc" is 12mm to 18mm, and about 20mm long
https://sdp-si.com/eStore/PartDetail.asp?Opener=Group&PartID=9872&GroupID=372

Smallest shaftloc pulley in HTD-5mm is 19T, and all of them are only 15mm wide.
 
Interesting topic

I've a 1/2 Ti shaft, that I've rectified to 12mm but only until 35mm to the end so one end is still 1/2, the plan is to use a standard 1/2x BSA adapter on this side, and a custom 12mm bore adapter that mount a freewheel + a fixed sprocket on the other, this is for a suspension pivot jackshaft. See my build for reference http://endless-sphere.com/forums/viewtopic.php?f=28&t=25101&start=105#p673292
 
I think that a jackshaft behind the chainwheel that carries both the motor drive and pedal drive is much better than running the motor through a front freewheel. My reasoning is that (1) You have complete freedom as to what kind of bottom bracket and chainwheel you use, (2) There is no compromise to the structure of the bottom bracket (especially the spindle) and (3) an additional stage of reduction can easily be added somewhere between the motor and the aft located jackshaft. Just an added 2:1 reduction would change cadence of the GNG kit from 150 beats to 75 beats. The front freewheel is tempting because it allows for a very compact, contained reduction drive. The problem is that the reductions in two stages are too extreme. Drive pulleys or sprockets become too small to allow for reliable engagement and bends, and the driven pulleys get way too large.
 
I have been a fan of the urbancommuterstore.com's M-Drive. 1/2-inch shaft parts have proven their usefulness. Part of my interest in 12mm shaft parts, is that a hard-to source 16T pulley made for 1/2-inch can't be shrunk to fit 12mm, but a 12mm shaft part can be bored out to 1/2-inch if desired.

That same 12mm sprocket/pulley will slip right onto an 80-85/80-100 motor shaft.
 
maedler sells 25mm T5 pulleys. They come with 8mm bore, but they also offer custom bores. Best is: free shipping within Germany :D
http://maedler.de/Product/1643/1616/986/992.aspx
Already ordered chains and gears from them. Reasonable prices and good customer service.

Helical gears from india, customizable maybe not for private customers (not sure yet) http://www.hariharengg.com/spur-helical-gears-681120.html
 
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