So again, it should take our kart about 15-16 seconds to get to 30MPH if all of the above is correct.
My apologies. Without double checking the output figures you gave I simply assumed you meant a modern Mini.
So for todayâs mini we are talking 162lbs-ft @ 1250 RPM and 2605 lbs.
So more like 16lbs per lbs-ftâŚ
For what itâs worth, this all sounds on par with the typical 'tween / young teen go-karts of yore running the commonly available 3-5 hp B&S motors. Their torque output in lbs-ft was pretty much the same as their rated hp without some tinkeringâŚ
Donât forget about the"ground effects"of driving a vehicle with your butt just an inch or so from the ground and in the open air. That adds roughly double the speed, halves the acceleration to speed times, and generally ups the fun factor. Itâs what sells Morgans, Ariel Atoms, CampagnaT-rexes, and most motorcyclesâŚ
Sorry, I wasnât aware there was a difference in weight. I just did a google search for small cars and came up with the numbers for the mini I referenced. Never really be a âcarâ person.
Wasnât aware what the torque ratings were on 3-5 hp B&S motors, but as I recall they seemed much faster then what we are talking about for this go kart (ie >45mph)
Got the motor mounted in a test box, now just need to secure the axle to something to test it out driving the axle. Here is a video of spinning it up to full speed (should be 7.5k rpm, but havent confirmed that) for a few seconds with no load
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Brandon & Space Kart Team,
An impressive job of design / prototyping / digital manufacturing.
After I read the description a while back, I really wished I could have taken this class but I had too many Saturdays booked up in advance. It did inspire me to take a short course in Solidworks offered at Richland, but I hope Mr. Frank Lima offers this again soon.
JAG âAll Physical Objects In the Universe Begin As An Ideaâ MAN
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We clamped the Drivetrain onto the pallet jack to test it out, amazingly it worked
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Ditto what Jagman says. I desperately wanted to do this, but was already overextended for this summer. Please offer this again!
Watched the power up on the bench, but I missed the test run in the parking lot. Dammit!
Looking good!
@Brandon_Green Is this with the plastic coupler?
Yeah the plastic coupler is working great, we measured 30 foot pounds at the drive axle using the digital torque gauge (through the clutch slippage), at the 4.75 to 1 reduction that means there was at least 6 foot pounds going through the coupler with no problem
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That looked dangerous as hellâŚhehehehe
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We ran a number of very successful tests and gained a lot good info. Had a ridiculous/insane amount of fun in the process. Improving on the fly w/whatâs available. Enjoy the picts.
Taking the test jig to next level.
Resolving minor alignment issues.
Held together w/clamps.
This could get interestingâŚ
Final adjustments and checks before the launch.
How do I ride/stay on this thing!?
Hold onâŚ
Surfing the pallet jack kart.
More clamps to adjust/retain chain tension and a seat for the driver.
Wind in the hairâŚoh yaaa!
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After spending way too much time machining on $5 wheels, we can now bolt them directly to standard american bolt pattern gokart hubs (3 holes on 2.5" diameter, but 2.56" diameter seemed to work better for the hubs we have). Of course no sane person would attempt to use non speed rated hand dolly wheels on a 30 mph gokart, but it has been done before in the power racing series, we shall see what happensâŚ
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Them guys are some crazy pallet jack drivers!
So turns out we have not gone down the cheapest path and will spend about double what we wanted to in order to afford 2 karts. I just put together the bill of materials so far, and we probably have another hundred to go at least for the chassis materials. A lot of the mechanical parts could have been sourced cheaper, but I went with what was the quickest and easiest to find (defaulting to amazon). But in the end we will have a unique completely custom built wooden brushless electric kart.
So far we have spent $1,148.72, not including shipping / tax, charger, powersupply, discharge box, (The ESC was donated, so we have actually spent 200 less than that, thanks @David_Walker !)
~700 for motor, batteries, controller, wire, switches
~400 for mechanical parts (shafts, wheels, sprockets, bearings, hubs, spindle)
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Brandon,
If you only spent double was was planned for a kick ass result as seen in the videos, I am still impressed all to hell by the efforts of everyone involved.
Great documentation of the process, BTW. This is newsworthy and original material. Now if you can âbulletproofâ it for Burning Man and add a flamethrower, you are galactically good to go.
Which gives me an idea for a new topic⌠but let me think about it first.
JAG âKermit The Frog Reporting Live From DMSâ MAN
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Itâs an electric kart - tesla coil or something thematically appropriateâŚ
I just Googled âSpace Kartâ to see what came up, and this image was the 1st on the listâŚ
I started working on the next test mule, In addition to having 4 actual wheels, we will be evaluating just how strong are wood screws? Here it is about half done
There are just 3 screws holding the front spindle on to some sandwhiched 2x4s (which are each just screwed into each other), it at least didnât immediately splinter when I stood on it
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Pretty sure youâre now qualified for frame production on Morgan MotorcarsâŚ
Is the front fork getting flipped, so you can drop the handlebars niceânâlow for a low CG of rider?
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