Total Time Spent: ~15 Hours

Journal

Day 1 - June 6

Brainstorming what parts to use: - Engine: either a cheap aliexpress engine, or a predator 212 if budget allows - Motors: either cheap hoverboard motors, or a good one like an my1020

(The more expensive ones would obviously be better, but I'll see how much everything ends up costing in the end) - Metal will likely be random scrap metal I have around, or some from metal recycling. Not too sure where to get metal. - Wheels are pretty good and cheap at harbor freight - Or can possibly use the hoverboard wheels - Not sure where to get parts for steering mechanism

I've created a rough model of the go kart:

I tried to keep it simple while still keeping it professional.
And I kind of kept adding stuff to it as I made it. At first it was just a super basic frame. Then I turned it into a truck. Then when doing the steering wheel I added the elevated beams on both sides. The result turned out pretty cool.

Total Session Time: 3 Hours

Day 2 - June 7

Today was focused on figuring out what parts to use and creating the BOM. I had a rough idea when designing the CAD model, but only for things like the wheels, engine, and motors. For smaller stuff I had to spend quite a while thinking about it.
A few notable parts: - Steering wheel and seat: I tried look for cheap parts for both of these but all of them ended up way too expensive. Nobody is paying $30 for a plastic steering wheel. I opted to 3D print the steering wheel myself and buy a plastic folding chair for the seat. Folding chair is a little rough, cause I'm gonna have to cut the legs off to make it actually fit well. - Sprocket and chain: This was probably the hardest parts to find. Since the engine is this cheap chinese one from aliexpress, it needed a specific type of sprocket that would still fit on our rear axle. For this itself, it probably took around an hour to find. - Motor controller: Finding a good motor controller was harder than expected. I was planning to use one of those box ones with wires sticking out, but after getting feedback from soneone in the Hack Club slack, I found out about BLDC controllers which I ended up using. - Bearings: The tough part about bearings is that I needed a specific inner diameter and outer diameter. It was easy to find one or the other, but not both. The only place I was able to find both was on a specific site for bearings, but it was $5 for each one. I don't think Highway would like that very much so i opted for some cheap bearings on Amazon that arent the exact size, but close enough.

The total price of the kart ended up at just over $300. It's a little more than I was expecting, but it is lower than the $350 at least. That's if I can even get this accepted as a 10 point project...

I also spent some time refining the CAD model. The previous version was the right design but wrong proportion. It was far too big, so I shrunk it down. I also found that in the shrunken down version, it was only about 2 ft wide, so I ended up also having to make it wider and also make it a little longer. A couple more changes too, like the sprocket and chain, steering wheel model, and wheels.

Total Session Time: 6 Hours

Day 3 - June 8

Since the CAD model and BOM are pretty much done, I spent today refining both of those, as well as looking for some parts to buy.

CAD Changes

Originally I was planning to build the seat of the go kart from scratch out of wood, but decided it would only cost a little more to just get a standard foldable chair. Although I already decided this yesterday, I didn't update the CAD model accordingly, so I found a chair 3d model, stuck it on the car model, and chopped its legs off to where its much closer to the ground

BOM Changes

After double checking each of the links on the BOM, it turns out the hole saw kit didn't have a 1-3/8" saw, which we definitely needed. I had to look for a different one that did have it, and this new one has many more sizes but it's like $10 more. Hopefully Hack Club won't mind, because I kind of need them and buying them individually would feel like a waste.
I also added a throttle to the BOM that I will use to control the hoverboard motors.

Finding Parts

I'm guessing we're supposed to wait for the grant before buying any parts, but I'm going to buy some now and hopefully get it reimbursed later. First I wanted to get the two metal rods I need, one for the rear axle, and one for the steering. I picked up the steering axle at a Home Depot, but they didn't have the axle rod I needed. So I ended up having to go to a different much larger home depot to get it. I also looked for hole saws at both but they are way too expensive. I also picked up some washers that I'll need.

Oh yeah, and I finished most of the README file. Should be able to submit this whole project soon 👍

Total Session Time: 6 Hours

Day 4 - June 9

Today was fairly short. I fixed one thing and submitted the project.

I posted my project in highway-pitstop and it seems to be getting positive reactions. One person replied on it and said it would be helpful to know more specifics about the hoverboard motor. After seeing that I tried to find the exact model (which i couldnt find last time a tried) and I did end up finding it this time. It ended up being 400 watts instead of the expected 350 watts. It was an easy fix though, the same motor controller i picked also has a 400w version. The go kart should be nearly perfect now.

Day 8 - June 13

So two days before, alexren replied to my project and pretty much has concerns about if I can finish the project on time. I do believe i can so i replied, but it seems like alex hasn't really seen any replies.

Then yesterday, I decided to just start working on the project anyways regardless of if it gets accepted or not. Maybe even just starting it now can prove that i will finish it on time. I've had all my metal lying on a glass table covered in tools and it was all kinda dirty. I basically spent the whole day cleaning it all up and moving it all into the garage so i can start working there.

And now finally, today, I started doing real work, starting with learning to weld. I tried welding two pieces together but it didn't really work. Then I tried with something else that's a little bigger and it actually worked. But when i tried to weld something for a third time... my whole table shattered.

I guess I should have expected that from welding on a glass table... But tomorrow i'll buy a welding blanket and start welding on a plastic table instead

Total Session TIme: 4 Hours

Day 12 - June 17

For the past few days, I've just continued practice welding. I remember a day or two ago I kept trying to weld 2 pipes together, and it just kept snapping apart. But I bought new electrodes and they work like magic. Those 2 pipes I probably still have to grind down the excess, but I tried on 2 new ones and they are now solidly attached. Now I've basically got 2 long steel pipes, which I'll use for the two sides of the bottom part of the frame. Tomorrow I'll start cutting the ones that go in between, and maybe even weld them.

Day 15 - June 20

I've kind of wasted the past day and a half trying to get the engine to work. I swear it's like I tried everything. New gas, starter fluid, starting it manually, still nothing. I guess all I really did those past 2 days was weld 2 more pipes together. Now I've got 3 of these long pipes. Today I finally caved and bought a new engine.

It's a predator 212. I don't think I would have bought it if there wasn't a sale on it. I got it for $120 which is pretty pricey, but it's not bad considering its like double the power for double the price. I successfully got it to run, and it was so much easier to start then the Aliexpress one. Just fill it up, flick a thingy, and pull.
There are three problems though: 1. It doesn't have a clutch 2. It's pretty big 3. The sprocket I bought will no longer be compatible

For the clutch, I can easily buy one from Amazon to put on it. I've been looking for new sprockets and another concern is if the gear ratio will be enough. I could probably just return the other sprocket I bought for the previous engine. And for the size, I'm not sure. I might just have to raise the bed even higher, and put a hole in it for the gas.

Day 22 - June 27

So uhh i've kind of forgotten about this whole journaling thing. But I have certainly been working. I'll kind of split it into parts:

Plan:

I've kind of split this whole project into 6 parts. Here are they: 1. Design [COMPLETED] 2. Trial and error, buying parts and tools [COMPLETED] 3. Cut pipes [COMPLETED] 4. Cut holes in pipes [DOING] 5. Weld pipes together, complete frame 6. Install everything onto frame

Trial and error

There's been a lot of random stuff ive had to buy for this project. First I bought a drill press to drill holes into pipes easier. But just holding pipes under it is too unstable, so I decided i needed a pipe notcher too to hold it in place. So I bought some random pipe notcher from offerup. It was crazy nasty so I had to clean it up. And then I realized my drill doesnt fit the shaft. So I tried putting it on the drill press instead, but it just wouldn't stay on steady. And then that one kind of broke, so I bought a brand new pipe notcher. And even that one didn't work. So i kind of had to give up with the drill press and instead do a regular drill. So i then had to buy an entire new drill with a bigger shaft and yeah... Yap over.

Design

So I've already designed the model but i wanted to clearly have what pipes im using for what parts, how to cut them up, and basically just all the information i'll need to assemble the frame. Here's some examples:

Cutting pipes

So after all the trial and error, I finally started cutting the pipes. For now just with the angle grinder and not with the hole saw. I think it took like 3 days to cut them all, and that was after all the trial and error, which kind of ate up a lot of time. There wasn't really anything notable, just a bunch of straight cuts. Designing everything out beforehand was super handy. I could easily see what to cut, so all I had to do was measure, draw a line, and go for it.

June 28 to July 9 (Going to stop counting days)

With all of the straight cuts out of the way, I can move forward with doing all of the tube cuts with the pipe notcher.

The super cool pipe notcher process!!!!!!

So I thought this would be pretty straightforward. I have my pipes, pipe notcher, and thread cutting lubricant. It was a little trickier than I thought. Basically my initial strategy was this: - Mark a dot at the edge of a circle I needed to cut - Insert into pipe notcher, making sure it's straight if there's another hole it needs to be parallel to - Apply lubricant, set drill down into it, start drilling - Drill until either hole saw gets stuck in pipe or there's a bunch of smoke - In either scenario, apply more lubricant and continue drilling again

This strategy did seem to work for like the first 1/3 of the holes I needed to cut. But I sort of refined the process cause it was inefficient at times and even dangerous. Here are changes I made along the way and why: 1. Draw a full arc around where I need to cut - this way I won't have to keep checking the design for which side of the circle the dot is on 2. Instead of resting the drill on the pipe, then starting to drill, instead keep the drill spinning full speed THEN put it into the pipe - pretty obvious, digs into the pipe way easier at the start. idk why i didn't think of this at first 3. MOST IMPORTANT attaching the pipe notcher to the table - this one might seem strange, but it actually made it so much safer to use. Sometimes the hole saw would get stuck with the pipe, and it would then spin the entire pipe notcher around, either hitting me or falling off the table (or both). After I got a couple cuts from this happening, I finally just bolted it down to the table.

After making these changes, the process went a lot smoother.

More cuts

Now that the pipe notcher process was refined, I began to drill the rest of the easy holes (as in the ones that are on long pipes that are just centered in the middle). This did take longer than it should have, mainly because I began to spend more time on my Open Sauce project that I was gonna need to finish soon. So after like a couple days, all of the straight holes were cut, now there were the more complex ones. For holes that were centered at the edge of a pipe (so that there's only half a circle being cut into them), I had to sort of offset the shaft that the drill is attached to, so that it was no longer centered in the middle of the pipe. Then there were some short pipes that weren't long enough to be held in the pipe notcher. This was pretty hard to figure out, and I thought I was just gonna have to do it the hard way with a drill press. But I found that if i stuck it in, then just put another pipe locked into it to where they're touching and basically just stuck together, it basically works as if it was just one long pipe. And with the short pipes cut, I could finally move forward to the fun part - actually welding everything together!!!!!

I feel like it might seem I didn't do a whole lot in this time, but as my excuse, I really had to lock in on a project for Open Sauce and had less time to spare on this project.

Note: From July 10 to July 21, I was in San Francisco for Undercity and Open Sauce! Just want to make sure you don't think I was doing nothing for nearly 2 weeks lol.

July 22 - Starting Welding

With Undercity and Open Sauce out of the way, I could finally put my full efforts into this project. I started right away with welding together all of the metal I've already cut. This was probably my favorite part. Before welding, it still looked like I had nothing done. But just starting to weld stuff together, the whole thing just starts coming together. I welded in layers sort of, starting with first, the very bottom. It's funny, even though the bottom should be the strongest, I welded it first where my welds were not great. This was the very first part I welded:

You can probably see how I used the hole saw to cut circles into both ends of the pipe. The top has that crescent curve, and the bottom does too, already welded together to the longer pipe at the bottom. That short piece is the back piece of the bottom. Next, I would weld the other side on:

In this photo, that one side isn't welded on yet, but you can now more obviously see it's the bottom of a go kart. In the previous photo with just one side, I managed to do it very straight (as in like perpendicular) and it turned out really nice. For this second one, though, it didn't go so smooth. At first I tried welding it on very straight, then I burned a very large hole through the side, so I then had to flip it over and weld on a clean side. Little did I know, when I flipped it over, the previous weld that stuck out made it so that it was no longer straight. I didn't really notice until I stood up after I finished welding. Honestly I thought i was gonna have to grind it off and reweld, but it was able to bend a little... very forgiving.

July 23 to July 31 - Completing Welding

At this point (July 23) school started up again. Let's just say it ate up a little bit of time that I could be spending on this project. For the next week or so, I was kind of locked in, didn't take any pictures or anything, just straight up welding every night. You'll definitely see how it came along a lot better in the August 1 log, but I'll still try to describe it here. I pretty much finished the entire frame, which includes: - 3 more bars between the sides on the bottom - 6 slanted vertical bars holding up the upper layer of the frame - The upper layer of the frame, held up by the vertical pieces - 4 little legs for the chair to rest on and keep it more elevated

I don't remember every detail of what I worked on, so I'll just give little snippets of notable parts:

1. When continuing the bottom layer from July 22, I found out I could just bend the bent side out to fit a new bar in the front that goes in between them. It was kinda scary cause I didn't know how well the weld would hold up. But it ended up being fine! And I could insert it very smoothly
2. Now an extension to the last thing, I then had to insert two more bars between the sides of the bottom that support the seat. I should have probably realized that I should weld the inner ones before the outer ones, but didn't really think of that. Conveniently though, I didn't have to bend it too much to get it to fit. If i wasn't able to get it in, I would have had to cut it slightly shorter, redo the holes, and then it wouldnt even be as tight, so very glad it worked out!
3. I planned to assemble the whole top layer before doing the vertical parts that bridge them together, but it didn't work out too well. When kind of just laying it out on the floor, I realized that I must have either measured the back wrong, or I just got the number wrong when I was making it in CAD, because it was like exactly 2 inches longer than it was supposed to do. At first I was worried i was gonna have to cut the whole back to be shorter, but I realized, I could just make those pieces on the sides of the top that curve outwards just go up instead. Then I can technically make the back as wide as I need. If I didn't realize this mistake, I would have the entire top layer too long and honestly... idk what I would have done.
4. Following up the last one, now when I wanted to figure out how the kart should go, I basically assembled it all just loosely, relying on all of them going through the holes to hold itself together. It held together nicely, all I had to do was make sure the vertical pieces weren't leaning torwards a side. Now that I could actually see how it will all go together now, all of the vertical pieces were at the perfect angles that I can weld them at, so I started welding those first. After like 1 or 2 of them being welded, It was pretty solid. The top part was staying on nicely (although it wasn't welded on yet), and after that pretty much all I had to do was just weld everything together in the same way I already had it arranged.
5. A design choice that differs from my original design was instead of having a tall triangle that holds the steering wheel, its just a simple horizontal bar that goes across. Honestly I don't really know which option was better structurally, but just in terms of finishing the project, the whole triangle thing was just unnecessary. In the image below, I put red lines that show where the new bar would go. The two pieces higher up that form a triangle will just be forgotten.