The Holy Grail Project - Page 2

Justin LE · 2012-05-18, 02:00 AM

The adapter starts off as a chunk of 1" aluminum plate on a rotary table in the milling machine.

Justin LE · 2012-05-18, 02:05 AM

Then the outside surface is machined out. This will become the new right side of the Nuvinci hub, and the cavity in the middle is machined to a 72mm bores so that it can support a CSK35PP one-way bearing.

Justin LE · 2012-05-18, 02:08 AM

The inside surface here should just fit over the recently machined Nuvinci hub. Parting the metal piece this way out of what started off as just a square cutoff chunk of aluminum is always a bit magical.

The holes around the adapter flange will bolt to what's left of the Nuvinci spoke flange.

dragonzfly · 2012-05-18, 02:09 AM

I did not want that story book to end.
Please post more, its really cool.

Justin LE · 2012-05-18, 02:16 AM

For the actual wheel itself, I decided to use an off-the-shelf 20mm thru axle front bicycle hub rather than machining one from scratch.

The thru axle hub standard is 110mm wide, so it works OK with the 100mm ball bearing width of a unicycle frame, and by making a spindle that is 20mm OD then it becomes pretty straightforward to have a spindle that goes through the hub and rotates independent of the wheel.

The only minor modification I had to make to the hub was machining down the face for the disk mount so that the cog and chain which will bolt to it won't rub against the frame.

Justin LE · 2012-05-18, 02:19 AM

The square taper spindles I found at the bike shops were all too short, so I hacked up a cartridge bottom bracket, removed the spindle, and then cut it in half.

Justin LE · 2012-05-18, 02:21 AM

A piece of steel tubing was then turned on a lathe to have a 20mm OD, and a bore that just fit the spindle halves pulled from the bottom bracket.

Once assembled and welded together we had a square taper spindle that fit right inside the 20mm thru axle hub and which was long enough for the cranks to be properly clear the frame.

Justin LE · 2012-05-18, 02:38 AM

The nuvinci hub comes with a splined interface that a threaded adapter slides onto on which you then attach a screw-on freewheel. This had to be modified quite a bit to in order to fit a drive cog and the one way ball bearing. I decided to use a standard ISO 44mm disk bolt pattern, since there are fix-gear bike types who use the disk mount of a bicycle hub for a fix gear cog.

In my case, I had a set of 16, 18, and 20 tooth cogs with a disk mount bolt pattern from tomicog that I got in anticipation of this project.

So a disk was cut out of 1/4" steel plate with a hole saw, then drilled and tapped with a 44mm ISO bolt pattern, and then silver soldered to the splined freewheel thread adapter from the Nuvinci.

Justin LE · 2012-05-18, 02:40 AM

Here is the set of drive chain parts lined up how they will all fit together.

Justin LE · 2012-05-18, 02:43 AM

And then after sandblasting and making a few shims and spacers for all the alignments to work out, we finally got to test out the entire drivechain assembly just last week!

knoxuni · 2012-05-18, 02:45 AM

go JUSTIN

OutdoorJunkie · 2012-05-18, 04:02 AM

That frame is beautiful! Brilliant work!

scott ttocs · 2012-05-18, 05:22 AM

Beautiful work!

I did not realize you could braze stainless steel. Do you need special brazing rods?

Scott

dmacuni · 2012-05-18, 05:39 AM

Holy cow, what an amazing series of photos showing the evolution of an even more amazing project! Looking forward to seeing more results as you post them, keep up the brilliant work!

Dartmech · 2012-05-18, 06:52 AM

Over the years I've been a member of multiple car and motorcycle forums that have never had a post with such detail and commitment to the final product. Kudos my friend. Oh the world domination devices I would make with all that machinery at my finger tips...
BUT it looks like its going to be ridiculously heavy. I still wanna ride when you get done though.

2012-05-18, 02:00 AM	#16
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	1-way bearing adapter plate The adapter starts off as a chunk of 1" aluminum plate on a rotary table in the milling machine. Attached Images

2012-05-18, 02:05 AM	#17
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	Then the outside surface is machined out. This will become the new right side of the Nuvinci hub, and the cavity in the middle is machined to a 72mm bores so that it can support a CSK35PP one-way bearing. Attached Images

2012-05-18, 02:08 AM	#18
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	The inside surface here should just fit over the recently machined Nuvinci hub. Parting the metal piece this way out of what started off as just a square cutoff chunk of aluminum is always a bit magical. The holes around the adapter flange will bolt to what's left of the Nuvinci spoke flange. Attached Images

2012-05-18, 02:09 AM	#19
dragonzfly Rob O'Brien, Sydney Join Date: Dec 2008 Location: Blaxland. Blue Mountains Age: 42 Posts: 130	Woah....So Awsome I did not want that story book to end. Please post more, its really cool.

2012-05-18, 02:16 AM	#20
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	Thru Axle Hub For the actual wheel itself, I decided to use an off-the-shelf 20mm thru axle front bicycle hub rather than machining one from scratch. The thru axle hub standard is 110mm wide, so it works OK with the 100mm ball bearing width of a unicycle frame, and by making a spindle that is 20mm OD then it becomes pretty straightforward to have a spindle that goes through the hub and rotates independent of the wheel. The only minor modification I had to make to the hub was machining down the face for the disk mount so that the cog and chain which will bolt to it won't rub against the frame. Attached Images

2012-05-18, 02:19 AM	#21
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	Spindle The square taper spindles I found at the bike shops were all too short, so I hacked up a cartridge bottom bracket, removed the spindle, and then cut it in half. Attached Images

2012-05-18, 02:21 AM	#22
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	Spindle (cont.) A piece of steel tubing was then turned on a lathe to have a 20mm OD, and a bore that just fit the spindle halves pulled from the bottom bracket. Once assembled and welded together we had a square taper spindle that fit right inside the 20mm thru axle hub and which was long enough for the cranks to be properly clear the frame. Attached Images

2012-05-18, 02:38 AM	#23
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	Nuvinci Drive Cog The nuvinci hub comes with a splined interface that a threaded adapter slides onto on which you then attach a screw-on freewheel. This had to be modified quite a bit to in order to fit a drive cog and the one way ball bearing. I decided to use a standard ISO 44mm disk bolt pattern, since there are fix-gear bike types who use the disk mount of a bicycle hub for a fix gear cog. In my case, I had a set of 16, 18, and 20 tooth cogs with a disk mount bolt pattern from tomicog that I got in anticipation of this project. So a disk was cut out of 1/4" steel plate with a hole saw, then drilled and tapped with a 44mm ISO bolt pattern, and then silver soldered to the splined freewheel thread adapter from the Nuvinci. Attached Images

2012-05-18, 02:40 AM	#24
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	Here is the set of drive chain parts lined up how they will all fit together. Attached Images

2012-05-18, 02:43 AM	#25
Justin LE Mad Scientist Type? Join Date: May 2010 Location: Vancouver Age: 32 Posts: 92	First drivechain test And then after sandblasting and making a few shims and spacers for all the alignments to work out, we finally got to test out the entire drivechain assembly just last week! Attached Images

2012-05-18, 02:45 AM	#26
knoxuni wes style!! Join Date: Jun 2010 Location: central ohio Age: 18 Posts: 4,699	go JUSTIN __________________ Be a dumbass experience dumbass consequences its full circle of dumbass And then, do it again. That makes it an infinite loop!

2012-05-18, 04:02 AM	#27
OutdoorJunkie Addicted to muni! Join Date: Oct 2010 Location: Auckland, New Zealand Age: 17 Posts: 367	That frame is beautiful! Brilliant work!

2012-05-18, 05:22 AM	#28
scott ttocs Registered User Join Date: Oct 2008 Location: Irvine, CA Age: 54 Posts: 1,126	Beautiful work! I did not realize you could braze stainless steel. Do you need special brazing rods? Scott

2012-05-18, 05:39 AM	#29
dmacuni Registered User Join Date: Dec 2008 Location: Esbjerg, Denmark Age: 30 Posts: 184	Wow! Holy cow, what an amazing series of photos showing the evolution of an even more amazing project! Looking forward to seeing more results as you post them, keep up the brilliant work! __________________ Ken Looi - Nostradamus of the unicycle world???

2012-05-18, 06:52 AM	#30
Dartmech Registered User Join Date: Apr 2012 Location: Dallas TX Posts: 115	Over the years I've been a member of multiple car and motorcycle forums that have never had a post with such detail and commitment to the final product. Kudos my friend. Oh the world domination devices I would make with all that machinery at my finger tips... BUT it looks like its going to be ridiculously heavy. I still wanna ride when you get done though. Last edited by Dartmech; 2012-05-18 at 06:53 AM.

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