Battery Buggy B

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MadCow2357
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Re: Battery Buggy B

Postby MadCow2357 » April 27th, 2018, 12:50 pm

Hey guys, there are Scioly.org t-shirts for sale! There were new logo shirts as well as old logo shirts, but the new logo shirts are out of stock. Bernard says that they will only order new logo t-shirts if enough people want them, so I am trying to convince more people to buy the new logo shirts (I want one). You can have your username be printed on the back of the new logo shirts as well. :)
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Re: Battery Buggy B

Postby windu34 » April 27th, 2018, 6:32 pm

I would recommend at least 4-5cm for the depth of the hole (I think mine were actually more like 7-8cm). And yes it requires some trial and error. The advertised CF I used was 6.2mm square and my 3D printed squares were 6.55mm for a perfect press-fit. I found that adding 0.25mm when printing with PLA was pretty optimal
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Re: Battery Buggy B

Postby hippo9 » April 27th, 2018, 6:46 pm

MadCow2357 wrote:Hey guys, there are Scioly.org t-shirts for sale! There were new logo shirts as well as old logo shirts, but the new logo shirts are out of stock. Bernard says that they will only order new logo t-shirts if enough people want them, so I am trying to convince more people to buy the new logo shirts (I want one). You can have your username be printed on the back of the new logo shirts as well. :)

Shouldn't this be on the T-Shirt thread?
EDIT: NVM I see you can't reply :D
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Re: Battery Buggy B

Postby MadCow2357 » April 27th, 2018, 8:06 pm

What do you mean I can't reply? :?:
Also yeah it should be on the t-shirt thread
Sorry. I thought that people were not looking at that thread enough. Sorry for the annoyance.
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Re: Battery Buggy B

Postby MadCow2357 » April 27th, 2018, 8:07 pm

Woops I see what you mean yeah I can't post on the t-shirt thread
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Re: Battery Buggy B

Postby MadCow2357 » April 28th, 2018, 5:29 am

hippo9 wrote:
shrewdPanther46 wrote:He is saying u can trial and error your way to the appropriate size for a press fit.

Yeah, and I don't know if your does this, but I've seen 3D printers that can print carbon fiber.

Yeah, no. My school has a Makerbot Replicator though. I have been making my parts out of ABS, which I believe is stronger than PLA. Right?
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Re: Battery Buggy B

Postby shrewdPanther46 » April 28th, 2018, 5:38 am

pla is more brittle, ABS is more prone to warping. generally, pla is a lot easier to master and work with
salty

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Re: Battery Buggy B

Postby MadCow2357 » April 28th, 2018, 6:02 am

windu34 wrote:I would recommend at least 4-5cm for the depth of the hole (I think mine were actually more like 7-8cm). And yes it requires some trial and error. The advertised CF I used was 6.2mm square and my 3D printed squares were 6.55mm for a perfect press-fit. I found that adding 0.25mm when printing with PLA was pretty optimal

I looked at your 2016 electric vehicle again, and it did not seem that the holes were 7-8 cm. Which joints were you referring to? I will probably have about 4 cm for the mid section joints.
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Re: Battery Buggy B

Postby windu34 » April 28th, 2018, 8:40 am

MadCow2357 wrote:
windu34 wrote:I would recommend at least 4-5cm for the depth of the hole (I think mine were actually more like 7-8cm). And yes it requires some trial and error. The advertised CF I used was 6.2mm square and my 3D printed squares were 6.55mm for a perfect press-fit. I found that adding 0.25mm when printing with PLA was pretty optimal

I looked at your 2016 electric vehicle again, and it did not seem that the holes were 7-8 cm. Which joints were you referring to? I will probably have about 4 cm for the mid section joints.

I started shifting towards 7-8cm in 2017. You are correct that 4-5cm should be sufficient though
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Re: Battery Buggy B

Postby PM2017 » April 29th, 2018, 10:19 am

windu34 wrote:I would recommend at least 4-5cm for the depth of the hole (I think mine were actually more like 7-8cm). And yes it requires some trial and error. The advertised CF I used was 6.2mm square and my 3D printed squares were 6.55mm for a perfect press-fit. I found that adding 0.25mm when printing with PLA was pretty optimal

Isn't that 0.35 mm?
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Re: Battery Buggy B

Postby windu34 » April 29th, 2018, 10:22 am

PM2017 wrote:
windu34 wrote:I would recommend at least 4-5cm for the depth of the hole (I think mine were actually more like 7-8cm). And yes it requires some trial and error. The advertised CF I used was 6.2mm square and my 3D printed squares were 6.55mm for a perfect press-fit. I found that adding 0.25mm when printing with PLA was pretty optimal

Isn't that 0.35 mm?

Oh shoot yeah my bad. I wonder if the carbon was actually 6.3mm squares because I applied this "+0.25mm" rule to alot of my 3D prints and it has held true for almost all. Of course this will vary depending on extruder temperature, heated/unheated build plate, material, etc
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Re: Battery Buggy B

Postby PM2017 » April 29th, 2018, 11:15 am

windu34 wrote:
PM2017 wrote:
windu34 wrote:I would recommend at least 4-5cm for the depth of the hole (I think mine were actually more like 7-8cm). And yes it requires some trial and error. The advertised CF I used was 6.2mm square and my 3D printed squares were 6.55mm for a perfect press-fit. I found that adding 0.25mm when printing with PLA was pretty optimal

Isn't that 0.35 mm?

Oh shoot yeah my bad. I wonder if the carbon was actually 6.3mm squares because I applied this "+0.25mm" rule to alot of my 3D prints and it has held true for almost all. Of course this will vary depending on extruder temperature, heated/unheated build plate, material, etc

It might have been 6.35mm since that is a quarter inch.
Do you recall which print settings and filament company you used?
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Re: Battery Buggy B

Postby MadCow2357 » April 29th, 2018, 2:45 pm

Ok, I have embarked on my quest for the perfect F1 Battery Buggy :D ! I 3d printed this file I designed in Tinkercad:
https://www.tinkercad.com/things/gvUEjg ... WOcrcBWqc=
My 8 mm square CF rod fits almost perfectly in the top square hole of the test print, but it is able to wiggle a little bit in the two bottom square holes. Is this normal?

The dimensions of each square hole are all the same: 8 mm side by 8 mm side by 1 cm depth. The hole in the middle is for the ball bearings.

Also, my test print came out a little bit warped. Not sure if that may be a problem. :?:
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Re: Battery Buggy B

Postby MadCow2357 » April 29th, 2018, 2:51 pm

Something is starting to bother me as well. Let me explain why. In the last post I mentioned that the rods could wiggle a little bit. windu used 3 CF rods on the bottom of his 2016 EV. And in a previous post windu described some sort of chassis torsion.
windu34 wrote:This is NOT a good reason to go with this design lol
The correct reasons are as follows:
Benefits: Elimination of chassis torsion and it allows for implementation of passive adjustable steering (as seen on EV 2016)
Cons: Difficult to implement correctly - fit between CF and 3D printed parts MUST be an interference fit or you WILL run into problems (you cant just glue/epoxy the rods in - the fit needs to be so tight that you have to lube the rods and hammer them in.
These pros/cons are not self-evident and i didnt realize them until I struggled with chassis torsion on my 2017 EV which required a complicated solution to solve.

Is 2 mm of ABS enough to keep the CF from breaking free of the 3D printed connector (see Tinkercad file)? And do the 2 rods on the bottom provide sufficient strength to hold my Battery Buggy together? Maybe I should put 3 on the bottom like windu did. The torsion thing is making me very nervous... :(
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Re: Battery Buggy B

Postby MadCow2357 » April 29th, 2018, 3:33 pm

First, an apology for asking so many questions (planning phase). Next, I would like to run this idea through you guys. Say I 3D print an attachment for my motor, and I either drill holes or have the holes "pre-made". Can I fill the holes in with hot glue, and then use a couple of wood screws to secure my Pololu 25D mounting bracket to the 3d printed part?
2017-2018 Events: Battery Buggy, Mystery Architecture, and Towers
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