Run in stand/dyno build.

[Terry Keeley]

Double post, mods please delete...

 

[Mike Bontoft]

20750RPM? I am surprised! Nice smooth acceleration through the range.

 

[Wasted wages]

Ouch !

 

[Randy Rapedius]

On a good note … the dyno is looking good.

 

[longballlumber]

She was Stroll'en

 

[Mark Anderson]

After watching Terry's journey, I got interested in building a dyno for myself. I started doing research and deciding how I wanted to go about it. Over Memorial day weekend, I had a conversation with Lohring at a race in Oregon. He told me that he was not going to build a new dyno and offered me the materials he had collected so far. Mike Hughes was at Lorings place a couple of weeks later and brought the parts up to me. Here is the first step. I got the flywheel machined and ready to go to the balance shop. I hope to drop it off this coming week. The disc started out 6x3. After trueing, it is a bit smaller. It's on a 17mm axle. Tight slip fit with loctite. Turned between centers after assembley.
I plan to use a bicycle freewheel rather than a one way bearing for an over running clutch. I am going to try a mountain bike disc brake. If that doesn't work out, it will build a brake like Mike & Lohrings dyno had. Next I need to build bearing blocks. This will likely be a long project. I am normally not home much in the summer do to work.

 

[Terry Keeley]

I think I would probably try the freewheel or something similar if I was to do it over.

One thing that might make it easier for you is if you could drill all the holes to align the pillow blocks etc. in one operation, with my little Clausing mill I had to move the base around and that caused headaches. Maybe even mount everything and line bore it somehow, alignment of the motor/shaft/wheel is critical.

I've done a bit of testing with mine so far but am just scratching the surface, I've used it quite a bit to break in motors tho.

Good luck and please keep us updated.

 

[Mark Anderson]

Yeah, I have been scratching my head a bit on machining everything for correct alignment. I think it will be three seperate sets. The flywheel and over running clutch, a love joy coupling, a third bearing block with a shaft and collet on the end opposite of the lovejoy, This block will be 2" thick and house 2 bearings, then the motormount. The clutch will be mounted to the engine, and will be coupled to the shaft with a square key. The brake and spin up pulley will be on the far end of the flywheel. Lohring gave me his drawings. I am putting my own twist on a couple of things. Today I was mulling over a simple jig on the mill to bore the blocks indexing off one side and the bottom. My plan is to just test Zenoahs so no interchangable parts to account for.

 

[LohringMiller]

Super. I dug out some rubber isolators and the square key stock. I also have some Aeromarine square collets. I don't know if they interchange with what you have. I'll try to remember to bring them the next time we meet,

Lohring Miller

 

[Mark Anderson]

No pics, But my solution for alignment is. I roughed out the bearing blocks, then bored them on the mill. I made a shaft that had a .0005 press fit in the bores. Heating the blocks in my bearing oven allowed them to be slipped on the shaft aligning the bores. The stack was then trued in the mill. The last surface trued was the bottom. When it was done a key slot was milled parallel with the shaft line and all of the bolt holes were drilled for mounting. The whole thing is going to be compact enough that I can drill and mill a matching slot in the base plate in one setup. The keys will align the bores. Hopefully this will be acurate enough. I made a dummy shaft to replace the flywheel while it is out for balance so that I could keep working. I need to order the Lovejoy coupling,
freewheel, and material for the base plate. This is actually going a lot quicker then I expected. Going to need some electronics soon.

 

[Mark Anderson]

I am a bit worried about the bicycle disc brake holding up. I made an adapter for one of my routers. I used a variable speed control from a safe distance and spooled it up to the full rpm of 29000. I feel a bit better about it now. Still going to be nervous about it for a while.

 

[Terry Keeley]

Sounds like you have a very good Engineering Department there!

The touchless Eddy brake works very well on my unit, takes the wheel from 24K to 10K in 15 secs or so, generates a little heat in the aluminum disk but much less than any friction type brake I'd guess.





Post some pix when you can!

 

[Mark Anderson]

My engineering department is mostly TLAR. I don't have much skill and mediocre equipment so I make do. This project is pushing me to think about the next move a bit more. Never really worked under .001 much before. Most of what I do does not require a bunch of accuracy. This is a whole different animal.
If this brake doesn't work out, I will be bugging you for some details on your brake.

 

[LohringMiller]

I actually built an eddy current brake from old computer disk drives. I doubt that you need this many disks.

Lohring Miller

 

[Mark Anderson]

Dropped the flywheel off at the balance shop today.
I was going to go with a high dollar freewheel for the over running clutch, but decided to give the one my local bike shop had in stock a try. It is a Shimano so is good quality. First step was to turn a 1.375x24 threaded adapter to mount it on the shaft. When the lovejoy joint gets here I can make the adapter for the drive side. At that point the bulk of the machine work will be done. Other then prettying things up. I left a lot of extra material not knowing where I might need to mount something. Thats the way it goes when you design as you build. I haven't really worked out supporting the Lovejoy. I am probably going to remake the intermediate shaft longer and put a bushing in the freewheel half rather than just relying on the freewheel bearings. We will see when I have it in hand.

 

[Terry Keeley]

I'm very interested to know how the freewheel works out, the sprags on my one-way bearing tend to wear quicker with the heavier springs and I may need a re-work down the road.

Any idea what data acquisition/software you'll be using?

It's coming along nicely, thanks for the pix!

 

[Mark Anderson]

I am going with the Datamite mini USB.

 

[Terry Keeley]

I am going with the Datamite mini USB.

Cool, I'd highly recommend the built in weather station, takes that variable out of the equation...

 

[Mark Anderson]

Terry
Did you upgrade to the pro vesion of the software?

 

[LohringMiller]

You definitely want the pro version of the software. We didn't have the weather station, but it's lots less expensive these days. We just used a standard temperature/barometer unit and put in the data manually. The software allows changing the input weather data for past runs if you need to.

Lohring Miller