We now have some parts and an engineering drawing of my homemade dyno.
CO

As Jesse James would say, "All that's left to do now...is everything."

CO, you will need a way to dissipate the heat out of the brake rotor, maybe run it in a water bath?
many dynos use an absorber, more of a paddle wheel in water or another method would be to drive an oil pump and you just increase the pressure or flow, just tossing a few more ideas at you.
I had started my own dyno stand using something similar to the dynamite absorber, just have not had a chance to finish, maybe this summer.

I looked at that dynamite absorber but I am a cheap. Do like that one though.
I hope you finish your dyno because I would really like some info to compare mine too. No oddys dyno sheets out there.
This will be done on the cheap. I'm still in the process of engineering this thing in my mine.
My set up will be interesting and you guys can shoot at it when it's done.
As for the heat dissipation thing I wasn't going to doing anything with regards to that. Was just going to run the vented rotor I got. The way I see it is that this rotor and caliper are huge compared to what is on an oddy. Also the run is real short and the power output of an oddy is pathetic compared to other stuff.
The oddy is rated at approx 30 HP at the crank. I also have a torque number. Got this info from Lee.
Since I am running it through a gearbox and not just off a crank, I estimate the torque to come in at about 290 ft/lbs because of the 10/1 oddy gearbox. That's allowing for a 15% drive train loss.
I may be off on my reasoning and math though. Failure is an option.
CO

Come on CO share the number at what rpm.
Keep hacking.

31 HP @ 6000 rpm @ the crank.
That's what Lee told me march 2018
CO

I am still on this project but waiting for parts. Waiting on the bearings but it's the weekend here now and it's snowing --- damn. Next week I will pick up the steel and start the build. Think I have most of it figured out. Some machining involved and some of the parts will be to big for my lathe so had to come up with and alternate idea. Looking foreword to this build regardless of how things turn out.
CO

The mad scientist is back in action.

Yes I'm working on it.
You get the idea.
Still waiting for some back ordered parts.
CO

I don't know why, but I thought this was going to be a bench top dyno for the Engine. Your way is better..lol As long as everything is bolted down good.

I choose this set up for several reasons.

One was SAFETY !!
When ever you are at work (or anything you do) common sense has to apply. If you are using a grinder then grab a brain and wear safety glasses. Wear steel toed boots (I do even in my home shop). Wear gloves. Common sense. Think about the job at hand.
If you build an Engine only dyno then the problem becomes a safety issue because you have to spin the dyno at 9000 rpm . This creates a balance issue. You are spinning a brake rotor at 9G and anything that is not balanced or goes OUT of balance becomes a serious issue. Someone is gona get hurt. If you build an Engine dyno you better do it right and not some skillbilly way like this.
By running it through the gearbox the oddy axels only spin 900 rpm. Still a safety issue but a lot more manageable. The draw back is the high torque. You choose.

Second is real data. With a chassis dyno you know what you are getting at the wheels. There are drive train losses so the Engine only data is not real.

Third is ease of build. Nothing has to be ultra accurate and super balanced. You can build it with junk yard parts and the cost is minimal. I paid $80 for the steel and the rotor/caliper/master were free from the local junk yard. My buddy the beer poacher works there.
CO

Looks like a great idea. I was thinking bench top also. This does simplify things. I'm very curious how you will actually measure the output. I will wait and see - something to look forward to.

Did you weld the shaft to the hub?

Measurements: I have a load cell. Any data will be collected by filming it on my camera, downloading to computer, pausing video to record data, plot it on graph paper.

Hub: No welding. The hub you saw on my bench was a spare that I used to just visualize things in my mind. It's just one of many spare parts I have for my machines. The dyno will be bolted to the wheel flange by a plate that will be mounted on the dyno shaft.. It's all bolt on.
The shock was removed and flat bar installed in it's place. This was so that I could make the axel level. I don't want to stress it at angle. Another reason was so that the wheel flange is square to the floor. The oddy suspension travels in an arc. Our wheels are cambered and square up as wheel travel goes upward. Another reason for this was so that nothing moves. I want everything anchored best I can with no movement anywhere. A shock can compress.

CO

Cool idea! Are you going to brace the opposite side somehow? Maybe create another shock brace and a 2nd plate for the other hub that just attaches to a static stand, that sort of thing?

I'd be worried that if you only attach to one side, it would tend to pitch towards the other (driver) side on load.

Can't wait to see how it turns out.

I really wasn't gona do anything with the other side.
The oddy's will be pushed up against my overhead hoist and tied up there.
The rear wheels will be removed and machine put on floor jack and jack stands.
I can't see it going anywhere.
CO

Had to come in the house for a coffee break.
I don't even work this hard at work.
Looks like I'm gona have to get a job just to have a break.

Machined a hub for the rotor.
CO

Got the hub done for the rotor. Still have to drill the bolt holes though.
Installed it and couldn't help myself. Ran a dial. I can hear Meth laughing. As it sits it has .011 run out. That's not good but nothing is anchored. It's all just tacked welded together. Welding pulls metal. Gave the rotor a spin by hand and it free wheels for 17 seconds. That's good. Tomorrow I should be able to make the plate and sleeve that bolts to the oddy axel but got to take Mom shopping first. Weather nasty here right now. The hold up will be that third bearing that is on back order. It's for the caliper.
Had a productive day and all went well so time for bed. No sense going to bed mad because you F'd something up.
CO

Progress slow but steady.
Made a new shock bracket because didn't like the two pieces of aluminum I had there.
Disk complete.
Plate for wheel hub made.
That bearing on back order is holding me up.
Another thing holding me up is the coupling from the shaft to the wheel hub. Spinning it in my mind as to how to make this accurate. Since I am not using a flex coupling like a lovejoy or similar, it has to be close. If it's not this thing will wobble around. Not good.
Another hold up is everyone wants something. Took mom shopping, took the neighbour kid up town, walk my brothers dog (everyday), pick up my brothers kid from work or the hair dresser and the list goes on.
CO

How true does the hub spin on the oddy?

That's a loaded question, no pun intended. Has to be better than that hunk of rubber spinning at speed.

If you look at the way he set it up I like it for the most part. Look how he removed the shock and leveled out the drive shaft and installed the ridged bar in place of the shock. The only issue here is the torque on the ridged assembly and the amount of flex of the drive unit in relation to the driven unit (measuring assembly). I now he will figure it out. Go Co go.

Depending on the rest of the set up a flex collar may be the solution. This will provide isolation between them and allow for tolerance differences and torque. Place this between drive and driven plates. Its common place to do this between direct Engine drive to hydraulic pumps.

FYI, google disc couplings

I deal with these a lot at work on hydraulic pumps.
The big ones have a spring that weaves between the elements. Then you bolt on a cover or some have a slide on cover you beat on with a hammer .
The issue here is that I am cheap. Don't want to spend big money on a coupling.
The other thing that I didn't mention yet is that when you set this thing up you have to possibly adjust the upright top linkage. I will use a carpenter square to make sure the wheel hub is square to the floor. This will have to be done on each of the machines prior to a run. This is not a 5 minute job building it or setting it up for a run. My real concern is actually disk run out. I say that because I don't want the brake to be pulsing. That will give the load cell a hard time and it won't lock on a reading. I have been thinking about this dyno thing for years. Just finally got around to it. Sometimes you just have to "make" time. I got lots of projects but they're all on hold until this is done. The sad part is that it will only be used 3 times and then it will be put in the dust bin.
CO

I have been waiting for someone to take a shot at me for not cutting keyways.
The problem is that I do not own an internal keyway broach or a shaper. I may have to make one of these for my lathe . I thought about it already but I need a high torque slow speed motur.
Since there are no keyways holding anything I will just make a chinamen for each item. Then I will weld the bits in place. Key note here: NEVER weld a shaft all the way around. It WILL snap at the weld. What you do is half or one third weld it and use a set screw if you can.
CO