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Adrian_Thompson
Adrian_Thompson UltraDork
5/16/13 6:35 a.m.

I somehow missed this when it was first started, this is awesome, great work with the cage. I can’t wait to see this finished. What tracks will he be running and is he displaying his GRM sticker to get in the magazine?

sachilles
sachilles SuperDork
5/16/13 7:38 a.m.

He has a grm sticker on the tailgate...He now wants the tailgate removed and a wing installed.....so a replacement sticker will be applied. He'll be on the Gator Racing Circuit....GRC for short. Just watch espn for the GRC events.

pinchvalve
pinchvalve GRM+ Memberand UltimaDork
5/16/13 8:01 a.m.

Is this my favorite thread ever? Yes it is.

Logan took his first ride on his John Deer tractor...and hated it. I will have to work on that!

Pat
Pat Reader
5/16/13 8:02 a.m.

That's awesome!

sachilles
sachilles SuperDork
5/16/13 8:11 a.m.
nepa03focus wrote: Man that last pic is awesome, lol.

I love that one too. There is something about it, reminds me of an old school Steve McQueen photo. I think it's the highwater pants with rolled up cuffs, leaning on the gator. Wish I didn't have all that other stuff in the background.

Adrian_Thompson
Adrian_Thompson UltraDork
5/16/13 9:08 a.m.

You know the long term development potential is awesome here. 12V to 18V, when he’s destroyed the gearbox and grown up a bit you can go for a 6hp gas engine, then tuning, then a steel frame under the body, then longer wheel base, then then then..

sachilles
sachilles SuperDork
5/16/13 9:30 a.m.

I think we are going with a gas kart for next summer regardless if the gator survives. You can get them with remote shut off etc. Seems like a logical next step. We seem to have had a baby explosion in my car club, so it would only make sense to hand the race gator off to another deserving young gear head. Even with the best batteries, with the hills on our property, it's not quite up to snuff. Actual functioning suspension would go a long way towards making the ride more usable. As you add volts you add weight, and he is growing, so there are some diminishing returns.

sachilles
sachilles SuperDork
6/19/13 8:35 a.m.

Just a little update. Tickled pink to have it in the actual magazine. He's been showing it to everyone. https://www.youtube.com/watch?v=wlREI3MDiY4

We have a hillclimb at Okemo next month, which happens to have a car show that saturday in the town of Okemo, that we are all suppose to show our cars off at. The plan is to have the gator there. The added bonus is they have a bunch of vacant level dirt parking lots for him to play around in.

He's now requested a spoiler for the back of it, guess he feels he needs more down force. So how the heck am I going to make a semi functional wing, that is light and semi cheap? Needs to not poke an eye out either. Toying with the idea of cutting up a rubbermaid garbage can as it has a nice curve to it, but the curve isn't really symmetrical. It will also cover the battery area, so I need to be able to remove it easily.

sachilles
sachilles SuperDork
6/27/13 10:40 a.m.

So it was time to address the power issue. The old 7.4ah 12v battery just wasn't healthy anymore. We were getting 5-10 minutes of run time in our hilly yard. The s style grote connectors would get hot and in general I wasn't happy with everything. So first up we needed some new batteries, and found a deal on ebay for 4 12 volt 12 ah batteries. The intent is to use one as the main battery. I also ordered some powerpole connectors. I had used them in my younger days with R/C cars and was happy to find they still exist, they seem like the perfect solution. Where practical, I soldered connections. I replaced thin gauge wire with thicker gauge wire from a scrap monster cable I had lying around. I'm pleased to report the first test of the battery that it lasted a full 30 minutes, without showing any evidence of weakening, before dinner was called and mom made us take a break!! All connections were cool to the touch, so all the effort on the connections paid off.

4cylndrfury
4cylndrfury MegaDork
6/27/13 10:54 a.m.

Awesome. Does Andrew have a good raceday support team? How fast can the pit crew replace a spent battery during endurance events?

sachilles
sachilles SuperDork
6/27/13 10:55 a.m.

So the next project on the list was EVEN MORE POWER!! Well I hinted at going with 18v power, with push to pass style of power boost. 24v has been done, but they say the gear boxs are the weak link. On further investigation, I found that it's the sudden torque of 24v off the line that kills the boxes. So my theory is that using a push to pass setup makes the most sense. The theory being Andrew takes off full throttle using 12v of power, then presses a button on the steering wheel, to get an additional voltage boost from a 6v battery. Well, I don't have a 6v charger...and I have some weak 12 volt batteries that we just replaced. So my theory was that I'd but in the older smaller 7.5ah 12v batteries we had as primary power before the new batteries arrived. I figure they have diminished capacity, and will probably work well as a temporary power boost. We have a grass lawn and the tires are worn, so I'm hoping all of this translates to less driveline shock. I found this wiring diagram on the web for push to pass functionality, so I can't take credit for it. Where it shows a 6 volt, I put in the older 12v.

Last night installed the push to pass setup which required cage removal. So you'll see the following videos without the cage. The speed is such now that I really like having the idea of a cage around my little racer. It's not DOM, but it will still deflect a fair amount of stuff. Below is the first test, showing the functionality. https://www.youtube.com/watch?v=LoUxPNG8W_c

Next is a track test.

As you can see, the thing is darn fast now. https://www.youtube.com/watch?v=UXUWwlltQUA One more showing how it deals with hills.

https://www.youtube.com/watch?v=fUFPoOL9jl4 This one highlights the lack of suspension, which had some unintended consequences with the new speed. I need to secure the batteries a bit better, as they broke their original tie down.

:edit for some reason I can embed the youtube vids in the preview but they don't show after posting.

sachilles
sachilles SuperDork
6/27/13 11:05 a.m.
4cylndrfury wrote: Awesome. Does Andrew have a good raceday support team? How fast can the pit crew replace a spent battery during endurance events?

We can always use more crew, just like anyone. Currently the batteries can be swapped in less than 20 seconds. However, I have to rethink battery mounting as the newly found speed causes a bumpier ride, shaking the batteries loose which is no good. With push to pass, there are now two batteries to swap as well.

beans
beans Reader
6/27/13 12:09 p.m.

Junkyard seatbelts cut to the right length?

4cylndrfury
4cylndrfury MegaDork
6/27/13 12:19 p.m.

LOL awesome teepee is awesome!

sethmeister4
sethmeister4 HalfDork
6/27/13 12:40 p.m.

I want to see some cul-de-sac turbo drifting!

sachilles
sachilles SuperDork
6/27/13 12:50 p.m.
sethmeister4 wrote: I want to see some cul-de-sac turbo drifting!

I live in the boonies....no cul-de-sac's around here.

However at the okemo hillclimb, they have some nice open parking lots he could safely goof around in.

sachilles
sachilles SuperDork
6/27/13 1:17 p.m.
4cylndrfury wrote: LOL awesome teepee is awesome!

You should see the zipline, into the tree house we are currently working on. In a holding pattern as my back called no joy after contorting myself lifting heavy framing and trying to screw it in place solo.

I love being a dad, and feel like I lucked out with having a darn cool kid that likes the stuff I do. I love these little projects, especially when he can help. Having a child makes it a lot more justifiable to do all these fun things that I secretly want and wish I had as a kid.

GameboyRMH
GameboyRMH GRM+ Memberand UltimaDork
6/28/13 10:59 a.m.

I wonder if it would be possible to use some electronics to smooth out the "KERS" engagement.

You could also try something like a motorcycle cush pack in the powertrain to save the gearbox. Maybe build something from a steering rag joint? I think this would be better for longevity and he could drift it care-free

sachilles
sachilles SuperDork
6/28/13 11:11 a.m.

Forgive my ignorance, I have no idea what a cush pack is, enlighten me please. Open to any ideas to help the the thing live longer.

GameboyRMH
GameboyRMH GRM+ Memberand UltimaDork
6/28/13 12:00 p.m.

It's a lot like a rag joint mechanism you'd see in a steering shaft, but it goes on a driveshaft - on motorcycles it's usually either integrated into the flywheel or after the clutch:

https://en.wikipedia.org/wiki/Cush_drive

Many have one in the rear hub but those would be way too big.

sachilles
sachilles SuperDork
7/8/13 9:06 a.m.

Nearly done. I say nearly, as you are never truly done with a race machine such as this.

A wing was desperately needed, with all this power, you need down force.

Thankfully we had a trashed plastic barrel around the house, if you cut it up, it was the perfect width for a spoiler.

What is more grassroots than recycling a barrel for aero?  photo IMAG0677_zps90a597e7.jpg The sawzall made quick work of it, but it required a little more work to make it smooth and semi straight.

With the wing in place it was time to put the sponsorship stickers on. Sadly I need a replacement GRM sticker, as the last one was lost with some of the "lightening" done to the gators body work. We've saved a place of honor for it.  photo IMAG0681_zpsd3e4b09f.jpg

Looks like we are ready to race. First race gator test video


First race gator test video(alternate in case the above vid link doesn't work)

Particularly proud how he turns into the skid at the end of the victory lap.

Next public appearance will be at the Okemo hillclimb this weekend in Ludlow VT. It will also be at the Ludlow car show Saturday evening.

sethmeister4
sethmeister4 HalfDork
7/8/13 10:19 a.m.

Good stuff dude! I was happy to see you guys made it in the mag in the current issue, that's pretty sweet! Have fun at Okemo!

ValuePack
ValuePack SuperDork
7/8/13 4:59 p.m.

And Andrew's HOW old again? Sheesh, kid can hold a drift and give a hell of an interview.

You ever bring him to Ascutney? I may bring my 4yo Miles to go to work corners for a day at the September event, he and Andrew would have a blast together.

sachilles
sachilles SuperDork
7/8/13 6:39 p.m.

He goes to every climb with me. He is four. Bring him on up, but keep in mind he can't work on the hill, you have to be sixteen. Younger guys can hang out at the bottom near the start line(with a parent). Drivers are very good with the kids around. Andrew usually hangs out with mom, if I'm in the car on the hill. Usually has plenty of cars and monster trucks to share.

ValuePack
ValuePack SuperDork
7/9/13 2:52 a.m.

This, I'll be looking into. Hopefully have a touch of vaca days left after NEFR.

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