Playing with the welder...Spidercarts Tarantula

[elkroeger]

The biggest mistake I made was a couple of weeks ago when I decided to build the engine bay w/o knowing the engine dimensions....

 

That sounds like where I work: Ideas are formed, meetings are held, math is done, more meetings are held, decisions are made, money is spent, things are built... and we don't know if we've improved anything because nobody knew any details about the original problem to begin with....

 

You'd fit right in over here.

[John Ranalletta]

Ya, but you can't let insufficient data slow down progress.

[John Ranalletta]

Slowly, but surely, it's coming together.

 

Mounted the brake caliper and master cylinder over a short weekend. All the line ties are temporary until the frame is disassembled and painted.

 

 

This image shows the brake pedal, master cylinder and connecting rod. I solved the issue of child vs. adult riders by creating two mounting points for the pedal and making a shorter connecting rod.

 

 

A cheap ass kill switch is mounted on the steering wheel temporarily. Simply it is tapped into the wire coming off the motor's on/off switch. That switch simply shorts the coil to stop the engine.

 

 

 

The rear axle went together easily. After the gas pedal and linkage is fabricated, it's time for a shake down cruise.

 

 

Thanks for looking.

[greiffster]

Slowly, but surely, it's coming together.

 

After the gas pedal and linkage is fabricated, it's time for a shake down cruise.

 

It's looking good. Why don't you bring it to the UN. We'll shake it down for you in the parking lot.

[John Ranalletta]

Today reminded me of the saying, "Everyone has a plan until they get punched in the mouth." Well, today, the punch came.

 

I found a local kart supply house w/i 30 minutes of my home; so, I visited to buy some parts and the guy proceeded to tell me just exactly how I'd screwed up a couple of issues. First, the spindle brackets need to have a 20 deg neg caster; so, off they came and were tacked on again.

 

 

Second, he said the accelerator linkage kit I bought from a catalog supply house was crap and proceeded to explain the whys/wherefores. He was right and sold me the parts I needed for less than $5. Need to turn up the heat for TIG welding the tube, but these are just fit up tacks.

 

 

When I told him the kart was for a 9 y/o, he looked at the pictures, saying, "The kid will have a hard time steering that cart with your pitman arm/tie rod setup. So, ca-ching, the solution is elegant but spendy - a rack and pinion unit.

 

 

This means new, shorter tie rods if I don't shorten and use a die to cut new threads in the existing rods.

 

Otherwise, it was a great day. Actually, I'm glad to learn this stuff. Might as well do it right.

[Glenn Reed]

Actually, I'm glad to learn this stuff. Might as well do it right.

 

That was my takeaway even before you said it. Getting good advice from a knowledgeable local source who helps you get things fixed before you find out about them the hard way? Priceless.

 

Great job, and thanks for taking us along.

 

(I do like Mike's idea, bring that baby to the UN!

[John Ranalletta]

Positive caster is correct, not negative.

 

Another day of learning in the garage. The rack/pinion switch required new tie rods; so, another trip to Comet. These guys are really helpful and the showroom is crowded with full race carts in the $ thousands.

 

Anyway, the rack/pinion required a bracket. Since this was a jury rig, I still wanted it to be functional and as elegant as possible.

 

 

It's TIG welded a full 6 inches which should be strong enough.

 

 

Adding the rack/pinion allowed me to delete the U-shaped mount seen in this picture.

 

 

 

The steering rod was shortened and welded to sleeve that captures the rack/pinion shaft. The sleeve is pinned to that shaft.

 

 

Discovered a tire won't hold air due to bad weld of hub to wheel flange. No problem as it'll be a few days before a shake down run.

 

Thanks for looking.

[OoPEZoO]

those welds are getting better and better.

 

This looks like a really fun project. Are you tracking costs? I realize the sky is the limit, but I'd be interested to know how much material cost are wrapped up in something like that.

[John Ranalletta]

Welds: Thanks. I have real issues with out-of-position welding and, as Mitch posted earlier, less-than-perfect vision is problematic. I wish I had more than a scratch start for better control of the arc, but "it's a poor craftsman who blames his tools".

 

"Are you tracking costs?"

 

No. The receipts are just piling up, but I've not added them up and probably won't. Too late now. Could have saved $ with a used motor and wheels and using steel instead of billet parts for hubs and axle.

[John Ranalletta]

Not much action at Casa Tarantula. Mulch to spread and cars to wash, etc.

 

Added a little bling to the kart today. The plans do not have provisions for heel pads. I suppose the driver just rests heels on the square tube. After sitting in the kart for a while, I decided that just wouldn't work.

 

Have some 3/16" aluminum diamond plate laying around so cut four 1/2-circles, welded on a bracket with the reel gun and attached them with self tapping screws. I chose 1/2 circles to contrast with the angular construction.

 

 

There's a pad for adult and child drivers.

 

 

I've struggled to find a quick-change setup so the pedals could accommodate an adult and a child. The most simple solution was to tack some throttle rod together. When the adult is riding, the pedals go forward then rear ward for a child.

 

 

Still have some adjusting to do on this throttle setup, but I think it will work well.

 

 

This picture shows the child and adult gas pedal positions. When running only one pedal will be attached.

 

 

Child's pedal setup.

 

 

Adult.

 

 

It's ready for its shake down cruise, but a front wheel wouldn't hold air. A water test disclosed a bad weld. Hopefully, I'll receive a new one soon.

 

Thanks for looking.

[John Ranalletta]

After a short time of being proud of the rack/pinion install, I was checking the kart over and twisted the steering wheel to check for alignment when I noticed something strange. Turn left and the wheels pointed right and vice versa. Shite! I installed the r/p unit upside down. I took an hour or so to cut the plate out, re-bend and re-weld.

 

Here are a couple of short vids of the first runs. It's quick to spin the tires on grass on takeoff. Still a few adjustments to make and an another 1/2 hour or so of running before breaking down for paint.

 

The low-oil shutoff system is still active and in the 3rd vid, that's what killed the engine on a sharp turn. I was going to take it off but decided to leave it as a boundary control when my 9 y/o grandson rides.

 

https://youtu.be/dRRpC2pJIck

 

https://youtu.be/pMNz-TbOzDA

 

https://youtu.be/UqMnBNLAVcU

 

 

[szurszewski]

Three thoughts:

 

That looks like a hoot!

 

You need a Steadicam

 

You should have left the steering upside down - you and your grandson, and any other regular riders would have acclimated to it quickly, and it would have been hilarious to watch others try to figure it out if you didn't warn them!

[LJR]

Thanks, those videos made me chuckle.

All smiles here, nice job!

[John Ranalletta]

With frames back from powder coating, final assembly starts tomorrow. My neighbor owns an Alloy Wheel Restoration Shop and has a powder coating setup. I've given over lots of moola for winter wheels and repairs for dinged up and bent rims, so I know the way to his shop.

 

Reassembly should take a few hours. Before dis-assembly and paint, I had the neighborhood kids each take it for a spin.

 

 

 

[AnotherLee]

'Tis a thing of beauty, John!

[greiffster]

+1. Love the red.

[Glenn Reed]

+1. Love the red.

 

That'll make it go faster...

[greiffster]

+1. Love the red.

 

That'll make it go faster...

 

I'm trying, but no way he's going to bring it to the UN.

[Bud]

+1. Love the red.

 

That'll make it go faster...

 

I'm trying, but no way he's going to bring it to the UN.

 

Dibs on first ride at the UN.

[John Ranalletta]

(Forgot to resize pics prior to uploading. Sure like forum at weld.com that automatically resizes all photos to standard forum size.)

 

Today was interesting. Took my time to reassemble the cart and ran into some problems. The driven sprocket on the the axle must've lost its key and spun on the axle, galling it and almost welding itself to the axle. Was able to free it up, add a key and tighten. A couple of other screws wanted to cross-thread themselves, but that's aluminum for ya.

 

A couple of things to note: (a) if you send the piece to powder coat with worm holes in your welds, you'll get powder-coated wormholes back; (b) powder coating decreases tolerances (threads, holes, etc.)

 

The steering gear went on first, because it was the easiest.

 

 

Then, the shocks and hinge bolts.

 

 

Then, the drive axle.

 

 

Brakes

 

 

 

Completed project with padded seat. I wanted to use red zip ties but couldn't find any. I considered clips but decided to avoid drilling more holes in the frame; plus, zip do a nice job of holding the brake and accelerator cable lines.

 

 

Video

 

That's all, folks. Thanks for looking.

[LBump]

Sweet...!

Your grandson is going to have a blast, lucky boy.

 

[Bud]

Well done John.

[OoPEZoO]

That really looks like a good time......building it AND riding it

 

I haven't made it past modifying power wheels yet......then again, my daughter can't even reach the gas pedal on that power wheels yet. All in due time I suppose

Don't want them to grow up TOO fast

[Bill_Walker]

...Here are a couple of short vids of the first runs....

 

https://youtu.be/pMNz-TbOzDA

 

https://youtu.be/UqMnBNLAVcU

 

 

Are you sure your grandson is going to be able to get your wife to give him a turn? She looks like she's having an awful lot of fun.

[John Ranalletta]

So, today, after test riding the finished product, she says, "We need to buy some land so we can get bigger toys."

 

https://www.youtube.com/watch?v=ZDQch9fyJD4

[John Ranalletta]

Governor bypassed. We're having some fun now, but it goes back into service w/ grandson.

[TEWKS]

Talented! Looks like a grin maker to me!

 

 

Pat

[John Ranalletta]

https://youtu.be/tNQytFa3_80

https://youtu.be/38NnMMK7nKI

 

I love the split second emotions. Happy, terrified, happy, terrified.

 

He loves the cart and had about 10 hours in so far. Big rain last night makes for great drifting/sliding and is turning manicured lawn into a bog, but what the hell else is grass good for?

 

Few problems cropped up but were remedied with some reinforcing and positioning. Biggest issue is hub throwing keys and spinning on axle. I think it's the wheel that on the inside during most turns and the wheel "chattering" is loosening it. We'll see.

 

Thanks for looking.