RC Drive Recumbent Trike Build

[The Toecutter]

but if I get the best now where do I go from there? That's what I'll tell myself anyway. Still thinking, so I'd appreciate any suggestions.

There are always going to be new things coming out to try, and desirable things being removed from the market. If you have the desire and the budget to justify it, you might as well get the best you can.

 

[Squilt]

300a, 84v, 10krpm, sensored inrunner, for $250
Freerchobby 66160

Started going to school again in August and blew my fun money on a motorcycle so this project is shelved for the time being. Still thinking about it though, and this motor looks good. Awkward shape but those specs for that price is hard to beat. Still happy with the 63100 I bought from them.

 

[Squilt]

I've got the Astro and I've ordered the ESC. I unfortunately missed my chance to get the headway cells before they went out of stock. I'm working on the drive train while I look for other batteries. I hope batteryhookup restocks before too long so I don't have to design a whole new battery pack.

I made some aluminum pieces to test my clamp design and see if I can get the plates to sit square to each other.

They look pretty square to me, though I'll need longer dowel pins to be sure.

Coming back to this after so long has me scrutinizing my design. I'm researching gear lubrication and I think my gearbox design might create large oil churning losses. Could someone who knows something about gearboxes give some advice?

 

[Papa]

You only need a small pool at the bottom of the case - just high enough for the lowest teeth (on the larger gear) to dip-in. Also, use a low viscosity (high quality) lubricant such as ATF. Chrysler used ATF in their 833 NP manual transmissions for years.

 

[Squilt]

I struggled to find relevant info online, so I decided to do a science.

I 3d printed the spacer between the polycarbonate face plate and aluminum plate so that I could test different housing geometry and measure its effect on lubrication. I started with large clearances between the gear and housing and incremented down to what I consider to be the minimum.

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I didn’t find an optimal middle point like I anticipated. I instead found that the simple design of the gearbox did nothing to keep the oil in the mesh area at higher speeds. The issue improved slightly as I brought down the housing clearances and used different viscocity oils and fill levels.

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I had to change something else, so I implemented a false floor and sump, which I had seen in images and diagrams from research papers. I also emptied space for oil to circulate around the pinion. With these changes I was finally able to reach the top speed with good lubrication and very little power loss.

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I'm going to do some more research before I settle on a final design and test it.

I have had a hard time finding the right spur gears I need. After a lot of looking, I found two choices. I can either use precision ground 8mm wide KHK gears, or simple hobbed Chinesium gears that are 10mm wide. Both will be induction hardened and made of C45 steel.

I will actually be doubling up these gears for a wider face width. I am leaning towards the china gears since I'm confident they should be durable enough when doubled up, and they're much cheaper to replace if necessary.

You can see from the images that I have the MakerX Go-FOC G300. I am very pleased with the design and though these experiments aren't exactly stressing it, it's doing a much better job than the Spintend controller I started my tests with and I've had no troubles with it so far.

 

[Hummina Shadeeba]

I sent aps a message about their 83100SW. The ratings they have for torque, current, and voltage are almost the same across all of the different kv motors. I'll likely pick a higher kv motor for more rpms and power. Though I doubt their 200kv motor can handle 15k rpm like the voltage rating would suggest. I was planning on a 2 stage reduction anyway. The watercooling is a plus. If the efficiency is good enough I might get it.

I used this 83100 motor and a two stage reduction but I swapped the center of the motor for a custom made one that fits bigger bearings because I read on this site that these motors aren’t designed for side loads. Been going fine for years. It’s possible to get the motor in parts. It’s got the thinnest lamination stator I’ve seen for sale.

 

[qwerkus]

The battery did need to move. It's now in an objectively better position for weight balance and space management, but I did prefer the way it looked before. I do like how the BMS is on display now, though. That wouldn't have been possible with battery where it was before. With the red Headway cells on top of this, it will be a very red trike. Therefore, bound for speed.
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I'm using the same clamp setup as I did for the idler. It's surprisingly rigid with 3d printed parts. Though I will be re-making it all in aluminum.

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I'm glad I worked something out that can still use all the hardware I bought/made and I didn't need to re-print everything.

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I need to cut the studs to get the battery closer I have some other fiddling to do. But then there won't be anything left but to buy the big ticket items. That being the motor, batteries, and ESC.

Did you finish the battery ? Seems to me that slightly sur-elevating the seat would give you all the space you need for a large battery.

 

[Squilt]

I bought the Headway cells when I saw they were back in stock, and I've begun testing their capacity.

The first tester I bought crapped out when I tried calibrating it. I got a refund from batteryhookup and ordered a replacement. It seemed properly calibrated but I was getting numbers that were higher than what they should be. This wasn't a big deal as I only wanted to compare the cells to each other, so I continued testing. But with each cell I tested, the capacity measured kept increasing. I went back to test the first cell, and the result I got was over 100mah greater than the first time I had tested it.

This is the ZKEtech EBC-A20. All the reviews I've seen are positive, and I don't see any mentions of this issue. I've tried calibrating the voltage and the current, but it doesn't change the drift in measurements. I tested the same cell three times with a half-hour rest in between, and each result was 21mah greater than the last. Any ideas?

 

[Squilt]

I've changed the cycle parameters and it doesn't seem to be drifting anymore. I've almost finished testing all the cells, and the cell with least capacity is about 8% lower than the best cell. This is why I bought 32 cells for my 28 cell pack. When ordered by capacity, the 28th cell has only 4% less capacity than the best cell. Which I think is acceptable.