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My meet on Saturday got rained out, so I couldn't be nosey in the pits. I am getting the front design (well, the first draft) figured out, and have some parts printing.

The rear is where I am all over the place. Belts aren't going to work on the smaller "gears" as I can't get small sprockets for the belt size that I think I am going to need. Just not enough teeth on the sprocket. So, I am going to have to use gears or chains, at least on the motor pinion. I am also looking at planetary setups to see if anything that I could use. There is a Dewalt drill in my shop that I have a feeling is going to be in pieces soon. Heck, I don't even know if I want to go direct drive, or some sort of diff. I have a contact with loads of Traxxas stuff, and he is going to send me a Sledge complete rear assembly, and I am going to see if I think that will work.

But the main problem I have is that I still have no idea where I want to be FDR or rollout wise. From just looking at pics, the direct drive setups seem to be in the 20-90-20-90 ballpark, so I am just randomly shooting for around 20:1 now. But again, that is a pure guess.

I did get an old school Parma body, so got that covered.

Looking at the frame more, I think the SWB semi frame is too short, so I got to looking at my unfinished Grand Hauler. I painted the chassis and a bunch of plastic on that a color that I ended up regretting, and I just stopped working on it because I hated the color so much. Well, this was my excuse to finally tear it down and start over. I ordered some new rails, and am going to use the old ones on the puller. They are too long, but I will cut to length at the end.

You could go old school and use a Power Wheels transmission.

Yeah, they were sometimes used back in the day as a cheap alternative. I don't know how well they actually did but likely weren't amazing. I mean you're not going to be pulling any major weight with that kind of stuff but it works.

The first puller I ever owned was a sportsman with a wire frame chassis, C-cab body made from styrene, and a Power Wheels transmission.

While I wait on some rear end parts, I am just experimenting with other things. I realized quickly that most people build pullers on a simple aluminum plate, and there is a reason for this, it is simple! You want something here, you screw it down there. I thought I was making a mistake with the ladder frame c-channel, but now I am digging it a bit. I am just going over board on the printing stuff, and some may or may not hold up, but it is fun to play with for now. Now that I have a template for parts fitting within the ladder bars, I can just adapt that to whatever the design need is. So, now I have semi SFA mounts, steering servo mounts, lipo mount (which can be moved forward or back depending on weight need and screwed in), and a front weight mount within the chassis. The weight mount can hold pieces of 1/2 steel bar as needed, and will have a steel plate installed on top of it. And then a weight box (just an aluminum project box) will be mounted on top of that for added weight as needed.

So, for the rear pumpkin, the current plan as of 1936 EST 5/15/24 is to run a Traxxas Sledge differential, with a spool, and 7mm HSS driveshaft to 12mm hex couplers and aluminum Clod wheel adapters. This will probably change, but it is the current plan. I am thinking about just designing / printing a pumpkin case for the diff to directly fit into the chassis. I would love to run the driveshaft under the chassis rails, but I think that puts too much angle on the pinion. The current plan is to put a couple of holes in the chassis, and run the ds through it. This would also allow the highest strength case mounting to the chassis rails.

Who knows, I am just making this up as I go at this point.

Yep, too much reliance on printing, but I like the idea of trying it and seeing what breaks, and can I make it better. I wasn't planning on this being such a print-centric build, but I am growing into the idea of it. An aluminum ladder frame and a lot of plastic between it.

Make sure your hitch is below the axle line

The hitch actually goes above the axle line these days. You want the front end to be pulled up, then weight is added to counterbalance the effect. This puts a lot more down pressure on the rear tires (fulcrum point) for increased traction.

In the sportsman class, the max allowed hitch height is 4 inches.

Lowgear wrote: ↑Thu May 16, 2024 5:00 pm The hitch actually goes above the axle line these days. You want the front end to be pulled up, then weight is added to counterbalance the effect. This puts a lot more down pressure on the rear tires (fulcrum point) for increased traction.

In the sportsman class, the max allowed hitch height is 4 inches.

You need to quit yapping and start sharing! Ya been researching / engineering these things, prove it!

I played around a little earlier and started designing the rear pumpkin. This is a mock up piece, just working out dimensions. The final product will be much beefier.

It's always a good idea to over beef things as there's a lot of forces involved.

I know I know... I have to get working on my garden tractor class puller again. I had jwscab do all the machining on it late last summer. Then I worked on it a bit in the fall when it quickly got too cold to continue. Now that the warmer days are beginning again, I'll be picking it back up.

Here's a pic from last year of its hitch so you can see how high it sits above the rear axle. The entire puller ended up being complete garbage though which is why I'm building an entirely new one based off its design.

I still have no idea what I am doing, but I am doing it anyway! I keep having great ideas at about 5am of how I am going to work out something on this build, but when I sit down in front of it, the ideas aren't going to work. Oh well.

I have the basic design of the pumpkin worked out I think, if I keep it where it is. Right now, I have the d-shaft going through the chassis plates, but I may actually change it around and run the axle on top or bottom of the frame. Not sure on that one right now.

Next part is going to be drilling the HSS driveshaft for pins, at the spool and hopefully at the hex adapters. I have a couple of solid carbide drillbits, and am just hoping they will work. Then onto the drivetrain, which I still have no idea on. I have an old Graupner 1/8 nitro buggy that I stupidly converted to electric with CC electronics and Arrma drive parts, so I am going to rob them back soon and see if I can make something out of them. That drivetrain is what wakes me up at 5am.

Oh, and I named it! Since it is going to be a mostly printed rig with a steel backbone, I am going with Plastic Fantastic!

I officially attended my first RC pulling event today! But it was short lived as the group was a bit behind on actually getting started, and I had chores to do so couldn't hang out for very long. The group was experimenting with a new laser measuring system, and no one knew how to actually use it, and after a lot of experimenting, it was tossed out and the old school way of using a measuring wheel was brought back into play. I feel like a simple Bosch-like laser measure velcro'd to the back of the sled and pointing back to a piece of plywood at the starting line is a cheap and simple solution, but I was the new guy just showing up with a camera so I didn't get too into the whole thing.

There were only 10-12 divers total, and each participating in multiple classes.

A few things I learned while there and wish I knew earlier.

- You need three competitors in a class for it to be an official race. So, if you show up with a Class X truck, and only one or less competitors show up with a Class X truck, you can't run it. That class just doesn't run that day. This can get interesting though! If you have a Class X rig in your car, but you weren't planning on running it for whatever reason, but two other people show up with a Class X puller, they will kinda force you to run that rig so they can make an official race of it. So, what classes will run that day is flexible.

- The Garden Tractor and Slash classes were the most popular. The Garden Tractors are smaller rigs, and easier and cheaper to build ............. and the Slash class is based on Slashes, so again simple and easy to build. I would have gotten into one of these classes as a start if I had known. I am also kicking myself for selling off all my Slash stuff super cheap awhile back. I do plan on getting into the Garden class, and if I find a Slash cheap enough locally, do that also. My first rig is a Sportsman based rig as that is the class that appealed to me the most, but there were only three Sportsman rigs at the event today, which means it was close to being a non-race for that class.

- Kinda going off the above, you want to be involved in multiple classes if you want to enjoy the event. Once going, the racing goes quick, and one class runs and then another, etc. If you are only there with one rig, and enough others are there for you to participate, you will have a lot of alone time. But I guess you have to start somewhere I guess.

- Weight weight and weight. You want to max out the weight of your rig per the class, and if the tech table scale says you can squeeze another 4oz on, you go back and put 4oz on. Where you put that is the big question.

- Most everyone involved was very relaxed, maybe too relaxed ..................... except for one person! There was one female involved in the event today, and she ran the tech table. TBH, she was the only really focused person in the lot, and without her, nothing technical or official would have actually taken place! A vehicle measuring station, a hitch height go/no-go jig, and a very large sensitive scale were her domain. She was fantastic, as she would constantly yell at racers for needing to get their rigs through tech, and the usual response was "I am working on it, be there soon," and she would just yell at them again. She kept the world rotating.

- Not intimidating at all. There was just the perfect amount of trash talking, and nothing negative was spoken when someone had a bad run. Completely chill.

- Just about the time I had to leave, they were setting up the sled for the Sportsman class. This is the class I wanted to watch the most, but I really did need to get home. What surprised me the most though was that they were loading the sled with 52lbs!! The trucks are maxed out at 10lbs, and the sled is 52lbs! I was not expecting this! All of the plastic in the Plastic Fantastic is getting me concerned.

There are other things I learned, but with only being there about an hour, it wasn't much. Being my first time around the group, I didn't want to pry too much, and get too deep into someone's business, so I kept my conversations and questions light.

Thanks for the detailed account of things! It almost made me feel like I was there. It seemed like my kind of an event. Garden tractor and mini rod are both fairly new classes so they're pretty popular at the moment. Garden tractor though badly needs an official rule change to allow pumpkin tires since the TLT ones are so scarce.

For some of the larger model classes there's a lot of weight and forces at play which requires scratch building the entire puller out of aluminum and steel. You'll quickly find out what areas need to be beefed up more.

In order to get onto the track quicker, I decided to look into building a Slash Class puller. After looking into a couple of things I would do to a used stock Slash, I decided it would just make more sense to start with a Drag Slash (especially with a C10 body) if I could find one on FBMP for the right price. So for half the cost of a new one, I have a Slash that really isn't all that far from being a puller. I already have some WW2 wheels and tires for the rear, and some Losi drag fronts that look better than Traxxas ones. Need to lock up the suspension, at least the rear. Raise the rear body mounts to clear the tires. Figure out hitch and weights mounts, and then start looking into electronics.

Ran across this rig during my research tonight and it made me giggle a little. The gearing set up is what caught my attention, but the motors are the prize.

That's cool !

Do pullers suffer from torque steer with inline motors like that or is everything too "slow" for it to be an issue?

I wonder what their reasoning was behind mismatched motors, or more a case of one died and it was to finish an event, or just put whatever in it to sell.

And seriously.... Tamiya plugs?