Open Source Electric Supercharger

[rusty959]

Originally Posted by neutron256

I think I've found the battery isolator I'm going to use.
http://www.sunforceproducts.com/prod...PRODUCT_ID=153



Install is very simple, just on wire from the positive lead of your main battery and a second to the positive lead of your secondary battery. It also has a small ground connection for powering the unit itself.

What I really like about this is that it will also isolate the secondary battery whenever the units small ground connection is removed. This will allow me to use a much smaller relay.

Thoughts?

Seems reasonable for your needs, however after a couple minutes of searching I found no one actually selling it, all claim it is discontinued. Have you found it for sale somewhere?

[Gary in NJ]

Originally Posted by fenton

Very ambitious ... 10 psi at redline will take 21kw

Sent from my HTC One using Tapatalk 4

Easier to obtain then 1.21 gigawatts. But the generator in the trunk to get 21Kw will be loud and heavy.

"There's that word again. "Heavy." Why are things so heavy in the future? Is there a problem with the Earth's gravitational pull?"

[neutron256]

Originally Posted by rusty959

Seems reasonable for your needs, however after a couple minutes of searching I found no one actually selling it, all claim it is discontinued. Have you found it for sale somewhere?

It's sold under a bunch of different brands. I'm sure all made some Chinese company.

-Sunforce
-Battery Doctor
-Projecta
-WirthCo

Battery Doctor/WirthCo seems to be the most US distributer. I just ordered it through amazon for $78 free shipping w/Amazon Prime.

The question now is... Is is a piece of crap? Reviews I've found on it seem good.

[Grantmac]

So that battery isolator should take the place of some of the relays in the 12v P/24V S set-up then. It should allow both batteries to charge at 12V when they aren't connected in series.

So this now could be as easy as a single relay connecting the batteries in series.

I still think a small 12v battery will be required for the car's electronics however.

-Grant

[rusty959]

Originally Posted by Grantmac

So that battery isolator should take the place of some of the relays in the 12v P/24V S set-up then. It should allow both batteries to charge at 12V when they aren't connected in series.

So this now could be as easy as a single relay connecting the batteries in series.

I still think a small 12v battery will be required for the car's electronics however.

-Grant

The only place in a 12 to 24v setup I would use that relay is the single relay that will be between the two batteries while it is set to series. The one connecting the positives would be best to be a normally closed relay.
However, if you used this relay for that one place it could be used, you would still need another normally closed relay to connect the grounds. If you use a single pole dual throw relay you can get away with two relays total. Or as the case may be with me, two banks, since I plan to use multiple smaller rated relays grouped together instead of big ones. (technically four banks since I am planning a 36v setup)

[Grantmac]

I'm thinking of the diode isolator.

-Grant

[rusty959]

Ok, so. My gf has been doing some cad work for me. She has very little cad experience, but more than my none, so she has been a big help. Half of this has been done away from where I could show her what I was meaning, but as a proof of concept this does well.
But, it isn't complete as can be seen in several areas. Half the dimensions are just guesses as I don't have a turbo picked out yet. The cad motors are sized to the aquastar t20's although I am not planning on using them now.

As I've said recently I am currently planning on a 36v setup using some AGM batteries. Ive now bumped the size I want up to models that can run 750 cranking amps, and 50ah or so. I might go higher, we will see. Removing the front battery will leave me with a weight gain of 50 lbs or so, but this isn't bad considering how I wanted more battery for my stereo anyways. If I get something and it turns out to not be enough ill probably add in a capacitor setup as well. Or I may just go with smaller batteries and run a capacitor bank. We will see.

For motors I'm looking at some of the leopard motors. I am hoping to be able to run the 58110 or 56110 series but am having a hard time sourcing them. Each motor is rated 7600 watts, and I would go with the 960 kv one. Second choice is the 5898 or 5698 series, which I definitely have access to. They have a 1100kv model which would work ok with 36v, rated 6500 watts.
As you can see in the model with this setup I will have the chance to take advantage of motors with lower max rpm because I can just gear it up, and multiple motors for more total power. I will probably be starting with two motors, then stepping to three once I am ready to go for more power. With 3 motors I can do up to a 1:6 gear ratio, which of course will take the 30k max rpm of the motors up as high as I could want with a turbo. On the model right now is a 1:5 ratio just to see how it looks. I would be starting off probably 1:3 or so since it will get me where I want to be for testing and have more teeth meshing on the gears. If I find I need to step to 4 motors, Ill just have to use two pinion gears on the shaft and offset two motors to get the gear ratio I need. And of course upgrade my electrical most likely, lol. That would get me to the 25kw range max power which is a crapton to deal with.

The one saving grace I have here is how extremely low of a duty cycle Ill be running. The times Ill actually want full power will be short and a long time between. I may still need to upgrade my alternator etc, but Ill just write that off as another combined with audio expense, lol.

Gears may be a problem. I'm planning on using 1/5 scale r/c gears which are designed for these motors, so theoretically they should hold up well. If I end up having to replace pinion gears often, I won't be too mad. They are cheap in the grand scheme of things. Bearings were talked about awhile back, but I have some ceramic hybrid bearings reasonably picked out that are rated just shy of 100k rpm. They should hopefully hold up alright. Again if I blow one occasionally, I won't be too mad.

The controller has been discussed a bit in past pages as well, so I'm not going to go into that either.

Now I need to put in a reminder with the picture that THIS ISN'T COMPLETED. Its just a rough proof of concept. Notable things that aren't done is the size of the base that will sit in the turbo housing and the mounts between the two plates. Obviously the round things are gears, ain't nobody got time fo teefs. (Edit: I also just noticed it somewhat looks like the big gears are touching each other from this angle. They aren't. Each large gear is only touching the center small gear.)


I was having a hard time communicating to my gf through text exactly how to finish the lower plate, so we just left it for now. It will of course be a lot thinner for a good portion in order to fit under the snap ring. It started at this thickness for the shaft bearings. The mounts between the two plates will of course be much larger, and less sharp.

Feel free to pick at anything you see here. Obviously I'm still in early planning stages, and though there are many obstacles that Ill need to find a way around, I haven't found anything insurmountable yet. Ill try to answer the best way I can and/or work through some details.

[neutron256]

Originally Posted by rusty959

Ok, so. My gf has been doing some cad work for me. She has very little cad experience, but more than my none, so she has been a big help. Half of this has been done away from where I could show her what I was meaning, but as a proof of concept this does well.
But, it isn't complete as can be seen in several areas. Half the dimensions are just guesses as I don't have a turbo picked out yet. The cad motors are sized to the aquastar t20's although I am not planning on using them now.

As I've said recently I am currently planning on a 36v setup using some AGM batteries. Ive now bumped the size I want up to models that can run 750 cranking amps, and 50ah or so. I might go higher, we will see. Removing the front battery will leave me with a weight gain of 50 lbs or so, but this isn't bad considering how I wanted more battery for my stereo anyways. If I get something and it turns out to not be enough ill probably add in a capacitor setup as well. Or I may just go with smaller batteries and run a capacitor bank. We will see.

For motors I'm looking at some of the leopard motors. I am hoping to be able to run the 58110 or 56110 series but am having a hard time sourcing them. Each motor is rated 7600 watts, and I would go with the 960 kv one. Second choice is the 5898 or 5698 series, which I definitely have access to. They have a 1100kv model which would work ok with 36v, rated 6500 watts.
As you can see in the model with this setup I will have the chance to take advantage of motors with lower max rpm because I can just gear it up, and multiple motors for more total power. I will probably be starting with two motors, then stepping to three once I am ready to go for more power. With 3 motors I can do up to a 1:6 gear ratio, which of course will take the 30k max rpm of the motors up as high as I could want with a turbo. On the model right now is a 1:5 ratio just to see how it looks. I would be starting off probably 1:3 or so since it will get me where I want to be for testing and have more teeth meshing on the gears. If I find I need to step to 4 motors, Ill just have to use two pinion gears on the shaft and offset two motors to get the gear ratio I need. And of course upgrade my electrical most likely, lol. That would get me to the 25kw range max power which is a crapton to deal with.

The one saving grace I have here is how extremely low of a duty cycle Ill be running. The times Ill actually want full power will be short and a long time between. I may still need to upgrade my alternator etc, but Ill just write that off as another combined with audio expense, lol.

Gears may be a problem. I'm planning on using 1/5 scale r/c gears which are designed for these motors, so theoretically they should hold up well. If I end up having to replace pinion gears often, I won't be too mad. They are cheap in the grand scheme of things. Bearings were talked about awhile back, but I have some ceramic hybrid bearings reasonably picked out that are rated just shy of 100k rpm. They should hopefully hold up alright. Again if I blow one occasionally, I won't be too mad.

The controller has been discussed a bit in past pages as well, so I'm not going to go into that either.

Now I need to put in a reminder with the picture that THIS ISN'T COMPLETED. Its just a rough proof of concept. Notable things that aren't done is the size of the base that will sit in the turbo housing and the mounts between the two plates. Obviously the round things are gears, ain't nobody got time fo teefs. (Edit: I also just noticed it somewhat looks like the big gears are touching each other from this angle. They aren't. Each large gear is only touching the center small gear.)


I was having a hard time communicating to my gf through text exactly how to finish the lower plate, so we just left it for now. It will of course be a lot thinner for a good portion in order to fit under the snap ring. It started at this thickness for the shaft bearings. The mounts between the two plates will of course be much larger, and less sharp.

Feel free to pick at anything you see here. Obviously I'm still in early planning stages, and though there are many obstacles that Ill need to find a way around, I haven't found anything insurmountable yet. Ill try to answer the best way I can and/or work through some details.

Sorry I haven't sent you my CAD design for the compressor backplate yet. I haven't logged on to my CAD PC in a few days. Today is the one day a week I go into the office but I'll try and remember to send it to you when I get home.

If anyone else wants any of my CAD designs just PM me your email, and what file type you'd like. I work in RhinoCAD but can export to most file types. Eventually I'll post them for anyone who wants access, but they're still a work in progress and I don't like to post somethign that's half finished.

A couple of thoughts on the design:

-If you can seal the transmission housing it will probably extend the life of the gears greatly. At those speeds even a little dust can quickly tear them up.

-The connection between the top and bottom plate needs to be stronger (could be worked into a sealed housing)

-Are you running seperate ESC's for each motor? With this design even a slight variance in speed, and possibly just relitive position of the motor windings could cause the motors to end up fighting each other.

If I have some time I might play around with your design some in CAD and see what I can come up with. Something integrated into the backplate of the compressor shouldn't be too hard.

I like the concept, but with the forces involved my gut tells me it will self destruct. It will be interesting to see the results.

[nonicname]

rusty that's a great thought but wouldn't you think it's better to take baby steps and use 2 motors before you use 3?

just for my piece of mind make sure the motor gears don't touch each other, only the motor main fan shaft.
There's is going to be a LOT of torque so you need to make sure those motor mounts are REALLY beefed up.

Also it worries me that you say you guys don't have much experience with CAD. Gears are not joke. it's a very meticulous thing
to get to work just right.

[rusty959]

Originally Posted by neutron256

Sorry I haven't sent you my CAD design for the compressor backplate yet. I haven't logged on to my CAD PC in a few days. Today is the one day a week I go into the office but I'll try and remember to send it to you when I get home.
Thanks. And no rush, we won't be touching this until atleast the weekend.
If anyone else wants any of my CAD designs just PM me your email, and what file type you'd like. I work in RhinoCAD but can export to most file types. Eventually I'll post them for anyone who wants access, but they're still a work in progress and I don't like to post somethign that's half finished.

A couple of thoughts on the design:

-If you can seal the transmission housing it will probably extend the life of the gears greatly. At those speeds even a little dust can quickly tear them up.
I may consider some form of cover in the long run. I would like to get some airflow through because there will need to be some cooling of some form. Additionally I need to inspect the gears because as I said I don't expect them to last all that long.
-The connection between the top and bottom plate needs to be stronger (could be worked into a sealed housing)
Yes it definitely does, as I mentioned in my post. Those connections were one of those things I just told her needed to be there, we didn't discuss size.
-Are you running seperate ESC's for each motor? With this design even a slight variance in speed, and possibly just relitive position of the motor windings could cause the motors to end up fighting each other.
Yes, separate ESC's. This is a common concern I have heard from a few people. I am not worried about it. A freespinning motor will spin up to high rpm's with little throttle. What holds it back is a load, which also causes it to draw more current. Therefore all of the motors will try to increase the speed of the shaft, and so there isn't a chance of one being driven by another. Past extremely low motor speeds the individual pulses won't be distinquishable due to momentum and all that jazz, so also hopefully won't be a problem.
Multiple motors are sometimes used in a similar configuration in the RC world both in brushed and brushless configurations. One in specific is the Traxxas E-Maxx. But if it becomes a problem, well then I guess Ill have to figure something out, lol.
If I have some time I might play around with your design some in CAD and see what I can come up with. Something integrated into the backplate of the compressor shouldn't be too hard.
Feel free. I'd love to see what you can do, you are obviously a lot more experienced with CAD than I/my gf are.
I like the concept, but with the forces involved my gut tells me it will self destruct. It will be interesting to see the results.
Well, if it self destructs, yay science. lol. Ill either fix what went wrong or cut my losses.

Originally Posted by nonicname

rusty that's a great thought but wouldn't you think it's better to take baby steps and use 2 motors before you use 3?
Yes. I mentioned this in my post.
just for my piece of mind make sure the motor gears don't touch each other, only the motor main fan shaft.
There's is going to be a LOT of torque so you need to make sure those motor mounts are REALLY beefed up.
The motors will be firmly mounted to a plate and won't be able to move side to side, so they won't be able to touch. In the drawing I can still increase the large gear size another 20mm (they are 100 now) and still be fine, but like I said the angle makes it look closer.
Also it worries me that you say you guys don't have much experience with CAD. Gears are not joke. it's a very meticulous thing
to get to work just right.
I'm not planning on cutting my own gears. They are just there for sizing. The gears Ill be using are commonly available in the R/C world.
As far as the plates and all, the geometry is simple. If it takes us awhile to get it down on CAD, its not that big of a deal. Ill also be prototyping with a 3d printer so any discrepancies can be found pretty easily. Gear mesh will be able to be adjusted and set identically to how they do it in the R/C world.

I posted replies in red. I tried not to seem too blunt in my replies. Keep the criticism coming, The earlier I hear of potential issues I haven't thought of the better I can change my designs.

[neutron256]

@rusty959, Do you have Specific gears in mind? I'm looking at various sources for gears especially those that provide CAD files for their products.

[rusty959]

Originally Posted by neutron256

@rusty959, Do you have Specific gears in mind? I'm looking at various sources for gears especially those that provide CAD files for their products.

Only roughly. Been looking at the various mod 1.5 gears they use for the 1/5 scale trucks, primarily the HPI Baja Flux.
http://www.hpiracing.com/en/part/108730 - pinion gears for the center
http://www.integy.com/st_prod.html?p...6#.Uiin6T_4IQk - spur gears for the motors.

I was considering doing a composite gear for the motors, but am considering just doing the steel as I linked to. Most of the composite gears ive seen for those size are set up for a different type of slipper clutch and so would be hard to make a mount for the motor. With that steel one, I can just make a relatively simple adapter to fit the motor. Plus then I would expect the pinion gear to wear out faster, which is an easier change than multiple spurs bolted down in multiple places.

I doubt you can find cad files for these gears specifically, but I'm sure some general mod 1.5 gear files are available somewhere. When I get to gears more in depth I might see what else is available outside the R/C world, but so far ive just been sticking to what I know.

[neutron256]

Originally Posted by rusty959

Only roughly. Been looking at the various mod 1.5 gears they use for the 1/5 scale trucks, primarily the HPI Baja Flux.
http://www.hpiracing.com/en/part/108730 - pinion gears for the center
http://www.integy.com/st_prod.html?p...6#.Uiin6T_4IQk - spur gears for the motors.

I was considering doing a composite gear for the motors, but am considering just doing the steel as I linked to. Most of the composite gears ive seen for those size are set up for a different type of slipper clutch and so would be hard to make a mount for the motor. With that steel one, I can just make a relatively simple adapter to fit the motor. Plus then I would expect the pinion gear to wear out faster, which is an easier change than multiple spurs bolted down in multiple places.

I doubt you can find cad files for these gears specifically, but I'm sure some general mod 1.5 gear files are available somewhere. When I get to gears more in depth I might see what else is available outside the R/C world, but so far ive just been sticking to what I know.

I've been doing some checking on my lunch break. I think you're going to have a hard time finding gears with a larger enough outer diameter to allow propper spacing between the motors that have an 8mm center bore to directly fit the motor shafts.

The largest I could find is 36mm with an 8mm center bore. Which would probably be pefrect if you were using smaller 36mm motors.

Of course this will also depend on the size of the pinion gear used.

[rusty959]

Originally Posted by neutron256

I've been doing some checking on my lunch break. I think you're going to have a hard time finding gears with a larger enough outer diameter to allow propper spacing between the motors that have an 8mm center bore to directly fit the motor shafts.

The largest I could find is 36mm with an 8mm center bore. Which would probably be pefrect if you were using smaller 36mm motors.

Of course this will also depend on the size of the pinion gear used.

I'm not planning on using a pinion gear thus don't need anything with a 8mm bore. For the motors ill be making my own adapter similar to the spinners they use for airplane props. As long as the center is atleast 10mm or so ill be fine. If it turns out to be less than 10mm or so, Ill just have to make the adapter differently.