gemellocattivo.com

Which means "Evil Twin". Lets see your projects where you change boring into fun or create the fun from scratch.
It is currently Thu Mar 28, 2024 7:19 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 67 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7  Next
Author Message
 Post subject: Re: Dyno
PostPosted: Wed Mar 13, 2019 8:46 am 
Offline

Joined: Wed Jan 23, 2019 11:13 am
Posts: 27
One thing I'm not seeing, at least with the current designs, is how the water exits the housing. It's an important consideration for good control speed.


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Wed Mar 13, 2019 9:27 am 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
mekilljoydammit wrote:
One thing I'm not seeing, at least with the current designs, is how the water exits the housing. It's an important consideration for good control speed.

right, I didn't add that yet but the more the general design looks like a Stuska brake, the more the fill and drain will look Stuska I guess.


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Wed Mar 13, 2019 3:46 pm 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
Here's V3. Right now its a 2" thick rotor but it could go to probably 3", just increase the rib thicknesses....I'll hold that though prending some basic dimensions from the Stuska rotor..... then time to decide whether to continue on this path or do a toroidal type.....


Attachments:
Rotor V3 1.JPG
Rotor V3 1.JPG [ 59.43 KiB | Viewed 10308 times ]
Rotor V3 2.JPG
Rotor V3 2.JPG [ 92.26 KiB | Viewed 10308 times ]
Housing V3 2.JPG
Housing V3 2.JPG [ 25.37 KiB | Viewed 10308 times ]
Housing V3 1.JPG
Housing V3 1.JPG [ 57.3 KiB | Viewed 10308 times ]
Assembly V3 1.JPG
Assembly V3 1.JPG [ 70.75 KiB | Viewed 10308 times ]
Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Wed Mar 13, 2019 6:23 pm 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
Driving home happy the airbag and seat belt lights went off on my car it occurred to me that I should probably print a couple brake options and test with an electric motor and actually know which designs work.


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Fri Mar 15, 2019 8:07 am 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
24 hours later and I'm still liking the test a printed version idea....I'll need to trim them to control clearances but that's quick. I'm thinking make a Stuskaish, dynomiteish and the last 2 housing I posted with the last rotor so 4 versions to print and test. I'm thinking little DC motor that spins 15-20k, higher is I can find it cheap since small rotors will do very little at low RPM, then 2-3" rotors....I could probably go to 4".

Thinking about test rotor size yesterday I got looking more closely at the dynomite charts.....they confuse me.
https://www.dynomitedynamometer.com/abs ... charts.htm

The 13" and twin 13" make perfect sense. The rotor is going to be about the same OD at the Stuska and they have similar charts rpm wise. That is as it should be. but then the 11 (in 13" housing) has the same shape rpm wise.....so it must have the same rotor OD and isn't 11 anything, but maybe is a hp equivalent to their old 11" product. The 9" make sense....but the 7" peaks at a lower not higher rpm....all I can think is they were targeting a hP number and restricted water flow or volume which truncated the curve. Then comparing the 19 to the 13....peaks at nearly identical rpm which again is impossible which caused me to notice the 13" curve looks unnatural and truncated.....hmmmmm....that doesn't help me pick a test unit OD


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Fri Mar 15, 2019 9:06 am 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
35k rpm 12v motors for kids riding toys are cheap, $14.....that seems about right. A 10pack of 5mm seal bearings are $10...so 5 water brakes or 4 plus a spare set.


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Fri Mar 15, 2019 2:06 pm 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
Here are the 3 rotors I think I want to test. I'm leaning toward 75mm with a 5mm shaft. I'll probably setup up the simple 1st and see what it does....if its too much for the motor I can just turn it down and reprint the housing. Then I'll do 2 or 3 housing options that all these rotors should fit and we'll see what we'll see. There is still some risk that the results don't really scale because the water viscosity just acts different on small parts than big....but it should at least tell me if I'm thinking all wrong and I should copy someone who knows better.

edit - forgot the dynomite style....I'll need to draw that up too.

A simple vaned rotor
Attachment:
Simple Capture.JPG
Simple Capture.JPG [ 92.05 KiB | Viewed 10288 times ]


A kind of Stuska like thing
Attachment:
Stuska Capture.JPG
Stuska Capture.JPG [ 79.03 KiB | Viewed 10288 times ]


A fancier vaned
Attachment:
V3 Capture.JPG
V3 Capture.JPG [ 91.39 KiB | Viewed 10288 times ]


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Tue Mar 19, 2019 7:36 pm 
Offline

Joined: Wed Jan 23, 2019 11:13 am
Posts: 27
Incidentally, Stuska rotor is about 12" diameter, 2.5" thick with the pockets both on the stator and rotor about 1" deep. Tape measure measurements so not hugely precise but pretty close.


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Tue Mar 19, 2019 7:38 pm 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
mekilljoydammit wrote:
Incidentally, Stuska rotor is about 12" diameter, 2.5" thick with the pockets both on the stator and rotor about 1" deep. Tape measure measurements so not hugely precise but pretty close.


Thanks.....very close to what I was guessing


Top
 Profile Send private message  
 
 Post subject: Re: Dyno
PostPosted: Wed Jul 24, 2019 10:18 am 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4250
Looking at a used go-power DA-512 tomorrow that SHOULD probably handle my engine.....probably.

http://gopowersystems.com/wp-content/up ... Manual.pdf

Technically only 800hp....but it shows braking torque that is more like 1000hp and the new unit that is virtually identical is 1000hp....I think its just about proper water supply as the old manual says you might need a pump and the new one says you do need a pump, a big pump.

http://gopowersystems.com/wp-content/up ... educed.pdf

Even the new one the 2 rotor is not double the 1 rotor....it has 1 feed and 2 drains and seems not to get enough water and they seem not to care since most people are done at 7000 or 7500 and just buy the 2 rotor for more lowend torque....my guess.

But I'm pretty sure if I feed it LOT of water its a 1000-12000hp @9000rpm brake. Fingers crossed.


Top
 Profile Send private message  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 67 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group