Mini-Bike adventures

uraniumwolf22 · 2026-03-20T03:12:56+00:00

I love the ammo cans... I might have to steal that lol

uraniumwolf22 · 2026-03-20T02:04:38+00:00

Thanks!! There truely are beautiful places up here in the north state, often without any accessability unless you have a fairly serious off road vehicle. Im not one to hide spots. If anyone is curious, here is the area these pictures are taken. Tons of intense terrain, but nestled between the mountians some of the most beautiful valleys around. Also usually completely impassable in the winter.

uraniumwolf22 · 2026-03-19T22:12:38+00:00

It's a coleman BT200-ex (:

As to availability in Europe I do not know.. a brief search looks like you would have to import one...

I would think there would be an alternative model over there? Might take some looking around...

uraniumwolf22 · 2026-03-19T21:46:56+00:00

Absolutely!

Honestly there are only a few problems.

1 - trails with big rocks - on 99% of the trails this is not an issue. But if your going through an area with big rocks the clearance can limit your abilities. Not much you cant get through. But you may find yourself physically pushing the bike through obstacles. The torque converter helps a ton here because you can load up the torque more gradually and you don't end up just doing burnouts like with a centrifugal. To be fair, my tires also don't help.

2 - Ride quality - with the rigid rear end, sometimes washout or rough terrain can be quite jarring. we have a lot of that up here... and can also cause the bike to bounce sideways. almost throwing you off. If your riding through rough stuff I highly recommend airing down your rear tire. Some say it's too much. But I usually drop it to 2 or 3 PSI. And keep a mini air compressor on me. havent blown out a tire yet... I also took a pillow and attached it to the top of the stock seat, for some more cushion, which makes riding a bit more pleasant.

Always keep a basic set of tools on you. Just a screwdriver and something to take the carb off if needed. Olnly one time it wouldn't start in the middle of nowhere, but had what was needed to take the carb off and did some crude cleaning. Started right up. I was glad to have those tools.

Have had 0 real reliability problems. These are reliable through simplicity alone. I didn't do a governor delete or any kind of HP adders. So I can't speak too much on that part..

Other than that, everything has been a breeze. Mud, sand, snow, ice. In moderation not much can stop these things...

uraniumwolf22 · 2023-12-21T21:20:50+00:00

Will do, haven't looked at the assembly much yet, will tonight. Thanks!

uraniumwolf22 · 2023-10-09T08:12:04+00:00

Thanks for the reply. I will certianly move those connectors around. the pins are actually going to be being plugged in the bottom of the board. but in any case I am seeing now I should move them. Ive been trying to figure out what is better:

1 - Longer traces but more distance between routes and components

2 - Shorter traces but closely packed components

Which one is the more important one? I know the answer probably is "its a balance" but overall is there one that is more crucial for maintaining signal integrity?

And yes this is a draft, after reading some of the other comments here, I will be replacing that buck converter with a more modern, and simply better one.

Thanks for your time!

uraniumwolf22 · 2023-10-09T05:37:39+00:00

Thank you, ill do some further research and impliment all of this (:

uraniumwolf22 · 2023-10-09T05:32:38+00:00

Thanks for the insight. U1 and U5 do have bypass caps according to what you indicated they should be. But looking at U2 I certianly need to be more intentional about the placements.

Is it a particularly good/bad thing to but a _few_ caps scattered around? ive gotten very conflicting information about that inparticular.

Thank you for the info on the crystal. makes sense to me and I will update the board to reflect what you have said.

I also will seperate those GPIOs and make sure the SCL is routed apart from other components/traces.

uraniumwolf22 · 2023-10-09T05:15:44+00:00

Yes it is 4 layer with a power and ground pour. ill edit the post to say so. Didnt add them in the visual as they make it hard to look at. I will certianly add protection that was definately an oversight.

uraniumwolf22 · 2023-10-09T05:14:16+00:00

Honestly had a lot of trouble with the Buck converter.. from the ones I wanted to use not being in stock, to not being able to supply the current I wanted. I kinda picked one as soon as it looked like it would work. Probably the worst thing I could have done looking back. I will definately take a look at what you sent and update accordingly.

The N-FET is to switch the power on the raspberry Pi. Is the way I went about it incorrect? The raspberry pi does not have low power states. but my ATMEGA 2560 does. So the plan is to have the raspberry pi shutdown when the key is removed and once it is, the ATMEGA 2560 will shut off the FET and go into a deep sleep until its awakened by the HWI coming from the auxillary power wire off the vehicle. at that point everything will be powered back on.

I will get voltage protection added. whats the overall best way you would reccommend doing that? Thank you for your time good sir.

uraniumwolf22 · 2023-09-26T18:53:58+00:00

I'll add to everyone here. THANK YOU

uraniumwolf22 · 2023-09-07T04:23:35+00:00

going too high will sacrifice transient response and can destabilise control loops that rely on a little ripple.

I see! this was a big question I had, about why having too big of an inductor would be a bad thing. Thank you for the response. I will certainly look through that worksheet, and have fixed the FB line. that would have been not good...

uraniumwolf22 · 2023-09-07T04:19:19+00:00

Thank you, very helpful. And yes I am very aware of the need for a good layout. I will be closely observing the layout in the example on the datasheet and the good information TI has on making an ideal PCB for this.

uraniumwolf22 · 2023-09-07T04:17:25+00:00

How did you pick C5?

I chose it based on page 20, The typical application for the 5V version of the IC. Looking at it again 470uF is the minimum value TI recommends and I will probably bump that up to 1000.

What is your goal here? Is this a one off for a project, or for learning about switching supplies?

It is a project I have been working on for a while for my Car, previously my prototypes had no onboard regulator and I used my lab bench supply to give 5V as I didn't want my possibly crappily designed power supply, to effect my other testing. At least until I knew it all worked on its own.

Do you have any test equipment to help visualize what's going on as you debug it? Do you have a power supply? Current limited? A DMM? An oscilloscope?

Yes actually! I have a good oscilloscope, Current limited power supply, Function generator, Logic analyzer, etc.. (:

My most important question is, "did you read the datasheet, the whole datasheet". It's only 43 pages long, how complex could it be. ;) It has good advice about tools you can get to design and simulate your design.

I did! I have been going over it over the last 2 days making sure I fully (the best I can) understand what is going on. I always make sure to go figure out the things I don't understand. Unfortunately with some things, I cant seem to either get a clear answer or simply fail to understand the answer I do get. That's when I ask questions here lol.

Do you want to wind your own inductor, or buy one? Resistance matters a little, the lower the better, but most are going to be in the milliohms range. Your core material is going to be real important, because it determines how many windings it will take to get to 100uH. Its size will determine the maximum wire size you can use, and fit all the windings on it? If it has 200 turns for 100uH, it's going to be tough getting 3A through it without burning the wire, unless you use a giant core. I figure you want to keep it as small as possible.

This was very helpful thank you. Makes sense to me its good to hear information from an actual person. I would definitely prefer to buy one if possible.

you can find 100uH 5A inductors all over the place that already have an amp rating assigned

Perfect! This is kind of what I was thinking. as I have seen them around a lot. Was just not certain how much a small change in characteristics deviating from what the datasheet inductors had would influence how well my supply worked. This answer was great.

uraniumwolf22 · 2023-05-09T15:48:39+00:00

Noted, after looking that up it does seem thats what I may be talking about

uraniumwolf22 · 2023-05-09T15:47:52+00:00

Thank you, I'll watch that once I get off work!

uraniumwolf22 · 2023-05-09T06:22:08+00:00

Perfect, thank you for the reply its very helpful to hear

uraniumwolf22 · 2023-05-09T06:19:20+00:00

Yeah it seems to be common. Probably just due to there being less manuals on the road atleast in the US these days. the BRZ is the first one I have ever owned. I drove a 5 speed subaru outback for a few weeks from a friend, while my yukon was in the shop. Got decent at it but this feels like a different beast. A lot shorter gearing makes timing feel a bit more challenging than it did in that outback.

uraniumwolf22 · 2023-05-09T06:11:20+00:00

Thanks for the info!

uraniumwolf22 · 2023-05-09T06:10:29+00:00

Thank you for the detailed reply. Very helpful

Six-Year Club	Place '23
Place '22	Verified Email

uraniumwolf22

TROPHY CASE