New twin motor longboard project "Now running"

The new motor mounts are done. Here is a picture of one of the old mounts next to one of the new mounts. The old mount is on the right. The new mounts are around 4 times as strong as the old ones.

I hope to finish the board this weekend.

Matt
 
It is finished!

Here is a picture of the bottom of the board with the lower cover removed. It is a tight sqeeze fitting all the wiring at the rear. The wiring for the front two packs runs through the center spine of the frame because there was no room to run the wiring any other way. :)

The board runs fantastic. I love the "Punch Control" in the ESCs. It makes the monster power of this thing much more manageable.

It is charging now. Once charged, I will see what kind of range I can get out of it.

Oh, I am getting used to the speed and acceleration now.

Matt
 

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looking good

Do you know if the mamba xl2 has regen braking. I read it does but I never seen it measured

oh and how do the brakes feel? can u lock up the wheels at speed when butt boarding

i know its gonna be hella fast

what i want to see is a video of a full brake stop with the esc on the max brake setting
 
I will call Castle and ask about regen. I want to know myself. I know a couple of the engineers there. I think I can get a straight answer.

So, I pulled a max of 4,000 watts from the board today. Oh, on a full charge, it is running nearly 30mph under no load, 26mph loaded. That is VERY fast for my taste. I have found 80% end point setting is awesome.

Oh, the brakes are REALLY good on this thing. The highest I have set it for is 80%. However, even at only 80%, it nearly skids. So, this seems perfect. About the only problem with the DX3 is the endpoint setting. You cannot set positive and negative travel independently. Therefore, when I set the end point at 80%, it not only drops the throttle down to 80%, but the brake too. That is annoying because I like setting it down for my kids, and up for me. But, I want the brakes to stay strong for all of us. So, I have the brake set so it is a bit too strong for me (but easy to modulate) and a tiny bit too weak when the end point is set at 40% for their riding.

We played around with the board in front of my house for 30 minutes and only used 20% of the charge. Of course, much of that time was my kids riding at 40% throttle. If I had to hazard a guess, I would say the 6S-15,000 mah pack is good for roughly 10 miles of 15mph cruising (maybe more, I have to test it more to know for sure).

Matt
 
You should get much more distance on that pack. I can get 5 miles on a 5000mah pack cruising.
 
OK, I have about 3 hours of riding on the board at this point. I would say it is, indeed, good for 15 miles on a charge (at least).

I have had two problems. One is the seriously tiny set screws the motor pulleys use. They loosened up a couple times. So, I added a second set screw to each pulley and those are far larger than the stock set screws. Problem solved. Second problem I mention in my motor sync thread (not a big deal). Anyway, other than that, I have been riding this thing HARD! I am quite used to the power at this point. However, it still feels best set at 85%. 100% is just too much kick. I logged a maximum of 4,100 watts,according to the logger.

I had one minor radio glitch that was, shall we say EXCITING! I was running full throttle (around 25 or 26mph) when the brake spontaneously activated for a split second. That slight braking made my body react with rearward lean, then the throttle came back on and I almost fell off backward...... I have to tell you, I have a hard time imagining a wheeled vehicle that is more hazardous at such a low speed than this thing.

I love it! :twisted:

Matt
 
I would also check the batteries of your controller. Sometimes, I notice my board will act funny and it's usually due to my controller batteries being not fully charged. I'll switch my batteries in my controller and the issue will go away. Not sure, if that's your issue but worth a shot.
 
recumpence said:
OK, I have about 3 hours of riding on the board at this point. I would say it is, indeed, good for 15 miles on a charge (at least).

I have had two problems. One is the seriously tiny set screws the motor pulleys use. They loosened up a couple times. So, I added a second set screw to each pulley and those are far larger than the stock set screws. Problem solved. Second problem I mention in my motor sync thread (not a big deal). Anyway, other than that, I have been riding this thing HARD! I am quite used to the power at this point. However, it still feels best set at 85%. 100% is just too much kick. I logged a maximum of 4,100 watts,according to the logger.

I had one minor radio glitch that was, shall we say EXCITING! I was running full throttle (around 25 or 26mph) when the brake spontaneously activated for a split second. That slight braking made my body react with rearward lean, then the throttle came back on and I almost fell off backward...... I have to tell you, I have a hard time imagining a wheeled vehicle that is more hazardous at such a low speed than this thing.

I love it! :twisted:

Matt

Matt what you using to log? Great to see you are enjoying the speeeeeeed.. How are the CC ESCs by the way?.. (Thanks for your reply BTW)
 
I am using the on-board logging in the controllers. The Castle controllers have very good logging capabilities.

I will get some video footage on youtube once the weather cooperates. :)

Matt
 
A few more KW and you can take on this guy:
http://www.roadandtrack.com/features/web-originals/13-questions-jet-powered-street-luge-builder

Really nice work BTW...
 
I make extremely high powered electric bicycle drive systems that are also very compact and light weight. I have the capability of building a 30hp board weighing no more than 35 pounds. I have personally run 70mph on a recumbent tadpole trike with one of these drive systems (geared relatively low for power, not speed). The potential top speed on a luge may be something above 100mph (maybe a bit higher) with this type of electric drive. The twin jets this guy is using are in a league of their own. Those crazy things are 400 pounds of thrust combined. That is astronomical. The only downside with jets is acceleration. Driving the wheels generally gives harder acceleration, but lower top speed. Just give higher potential top speed, while limiting acceleration a bit.

At any rate, I am building one of these crazy twin motor drive systems right now for a 100mph land speed record attempt sometime next year on a tadpole trike.

I love high speed. That being said, I am married with 3 kids. I do not have a death wish. So, I will not be riding the trike. Actually, I am building the drive, and another few guys are building a riding the trike itself.

Here is a link to the 70mph trike I built a few years ago. Enjoy!

http://www.youtube.com/watch?v=WKAMus3oSdw

Matt
 
At any rate, I am building one of these crazy twin motor drive systems right now for a 100mph land speed record attempt sometime next year on a tadpole trike

just checked out that twin astro bike, sick... :shock:
http://endless-sphere.com/forums/viewtopic.php?f=6&t=37539&start=75#p808424

is there a build thread for this new trike?

is this some official record they are going for?
btw, a delta electrathon trike went 110mph at bonneville...
i believe on SLA batteries... but its fully faired.

didn't u sell that yellow trike?
why? looks fun...


this gas powered luge went faster than the jet luge,
although some would argue its technically not a streetluge anymore...

http://wackyboards.blogspot.com/2009/07/powered-streeluge.html
http://wackyboards.blogspot.com/2009/07/jet-luge.html
 
OK, Well I guess electric inline skates are next, and then what? An Inspector Gadget style rotocopter!! Now THAT could work!! And if anybody can do it, Matt can. We just need a test dummy, what's Luke up to these days? Hmmm, no, on second thought we need someone much smaller...
 
Man, now that this insane winter is ending, I have had the board out again. This thing has proven reliable, refined, and hugely fun. My boys constantly bug me to ride it.

I love this thing.....

So, are you guys getting back into boarding with the improved weather?

Matt
 
I went out riding today for a little while. On my straight away back to my house I saw Fed Ex delivering a couple of new c/v axles for my car so that changed any plans of another lap. Axles are now in though!
 
recumpence said:
I logged a maximum of 4,100 watts,according to the logger.
would you please show some evidence ? and in which conditions did you reach those 4kW please.
 
I did not take a screenshot of it. I can do that when I am out again, though. I have no reason to exadurate numbers. There is no need for that. I couldn't care less if people believe me or not. There are more powerful boards on this forum. So, I am not claiming anything too extravagant.

That run was with the throttle set at 100% on the DX3 under hard accelleration leaning WAY far forward. It really was no big deal. Each controller logged 2,050 watts for a total of 4,100. The board is not capable of any more power because when I tried pushing it harder, the motors screeched as the controllers lost sync from being pushed too hard. Honestly, that is far more power than is needed anyway. However, I have found it is fun when showing what the board is capable. Totally impractical to ride that hard under normal day to day riding anyway.

A longer wheelbase would be nice when trying to wring out this much power.

Matt
 
recumpence said:
There are more powerful boards on this forum. So, I am not claiming anything too extravagant.
[...]
Totally impractical to ride that hard under normal day to day riding anyway.

I am afraid there are misunderstanding in terms how much power the components are actually rated for and how much is actually needed & measured, (you probably know that)
This being said, I have no doubt an e-board using 4kW in realistic conditions is "Totally impractical to ride" unless it is really unefficient.
Above all, I believe it's fair to call the ratio of "components rated power / measured power" a "reliability factor"
 
I have gotten so comfortable with the board now. At this point, I have it set for 17mph top speed (55% throttle end point setting). I am enjoying slalom riding far more than general cruising. I can slide the board relatively well. It is shocking how much lean angle you can get on a board with good wheels before it slides. This thing slides very predictably.

I have somewhere over 100 miles (probably about 200) on the board without any problems. Not even a loose set screw since I finished the board. :)

Matt
 
I wanted to resurrect this old thread to let you guys know we ride this board a lot. It is 3 and 1/2 years old now and is totally problem free. It just runs and runs and runs. I have a few hundred miles on it at this point without any problems.

I just wanted to post this to let you guys know home-built stuff can, indeed, be very reliable.

Matt
 
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