Jump to content

Another 3D printed EUC project


MattJ

Recommended Posts

Hello all,

after reading your posts for quite a while now, it´s probably time to share some info on my own project that I´ve been working on lately.

After an unsuccessful search for an enclosure with sufficient battery capacity for my 500W Microworks motor, I decided to make an attempt to design and 3D print my own.
The housings on both sides are identical and, due to print size limitations, have to be printed in two sections, which are then stacked, glued together and secured with M8 threaded rods which go through the whole structure from top to bottom. Each housing can hold either two standard 2200/2900 mAh battery packs or one battery pack plus the mainboard. For that purpose, the housings can be divided into two separate sections. Underneath the top handle, there will be room for another battery pack, so all in all, it will be possible to connect up to 4 battery packs in parrallel, which should make it more likely that you have enough juice left to get back home safely.

Despite all this, I´ve been trying to keep the design as compact as possible, avoiding any sharp edges.

I still need to finish printing and fitting the upper parts of the battery housings as well as the top section. It´s a slow process, but I will post more pictures when there is more progress.

Cheers!

- Matt
 

MS14-528-01.jpg

MS14-528-02.jpg

Link to comment
Share on other sites

  • Replies 281
  • Created
  • Last Reply
53 minutes ago, OliverH said:

What kind of printer did you use?

A Makerbot Dual clone. I used PLA because it would be hard to keep ABS from warping on such large items.

 

Link to comment
Share on other sites

Hello again,
printing in progress - currently the upper handle part with battery compartment. As you can see it´s a huge part which will barely fit my printing platform and it takes about 20 hours to finish. Since the wall thicknesses are quite large on the handle part, I decided to try a combination of relatively strong outer and inner shell but slightly less infill. The idea is to have more air in between to act as a buffer in case of a crash. The battery housings however have thinner walls, so I am using more infill on those.
The upper part of the battery housing will be next (see first drawing). I still need to do some measurements and determine the exact amount of required extension inwards towards the handle part. The last parts will be the top covers for the left and right battery housings (second drawing). I will try to add openings for the charging socket and power switch to one of them.

MS528-03.jpg

MS14-528-04.jpg

MS14-528-05.jpg

@electric_vehicle_lover: Great looking EUCs you have printed. I wish I had mine up and running as well. Printing seems to take forever and the first print doesn´t always fit, so many parts need to be adjusted and re-printed. What´s your experience on crash resistance of PLA? It feels quite strong and hard to break, so I suppose it should not be that critical, especially if you add some bumper strip foam or similar.

Link to comment
Share on other sites

Mine crashed 2 times but that was no problem at all!! I am using walls of 4mm and infill of 10%. Your parts seems to be much more robust/large than my parts.

This motor and board are really nice.

Note: printed parts get really strong if you don't use the blower to cool the part while printing - I am doing that.

Link to comment
Share on other sites

4 hours ago, electric_vehicle_lover said:

Mine crashed 2 times but that was no problem at all!! I am using walls of 4mm and infill of 10%. Your parts seems to be much more robust/large than my parts.

This motor and board are really nice.

Note: printed parts get really strong if you don't use the blower to cool the part while printing - I am doing that.

Good to hear that there haven´t been any stability problems. That has been one of my main concerns, I do not want to risk squeezing or puncturing any of the batteries in a crash, so I´ve been trying to protect them as much as possible without making the design too fat. I´m very much looking forward to try the MW motor, heard a lot of good things about it, but haven´t yet had the chance to test mine. How much range do you get with two battery packs and your 500W motor? On my 350W generic, I get about 8 km per charge with a 2200mAh pack, under average road conditions without too many steep hills.

Link to comment
Share on other sites

The most problems a got on the few iterations I did on my design are: 1st: uncomfortable riding due to lack of space of legs and feet; 2nd: uncomfortable riding due to batteries and/or board being to far for the motor axis.
On my current design, the metal thread rods protect in someway the battery from lateral impact. Front impacts must be protected with big walls of the printed part.

My beach ride (mostly flat) is about 7kms and the battery gets at 50% (reading on the app). I use 2 x 2200mAh pack.

euc_ride.png

Link to comment
Share on other sites

Two more parts added, testing&checking measurements:
- upper section of the battery housing (one side only so far)
- top handle with battery compartment

Each part took around 20-24 hours to print.

MS14-528-06.jpg

Link to comment
Share on other sites

Well, your values are bad for 3D Printing statistics ;-)

I am using 0.4mm layer size and my parts takes about 3.5h (I have 8 parts that take about 3.5h and 4 parts that take 20 minutes each).

I just finalized the 2nd EGG EUC and now I really like current design and I will stick with it:

2016-06-18 18.23.01 (Medium).jpg

Link to comment
Share on other sites

6 hours ago, electric_vehicle_lover said:

Well, your values are bad for 3D Printing statistics ;-)

I am using 0.4mm layer size and my parts takes about 3.5h (I have 8 parts that take about 3.5h and 4 parts that take 20 minutes each).

I just finalized the 2nd EGG EUC and now I really like current design and I will stick with it

 

Fortunately I´m still waiting for my batteries and outer tire from China, so I still have a little time to print. Only two more parts = two nights of printing. However, I am running out of filament and my replenishment has not arrived yet, so the end result might have some strange color combinations on one side... I´m printing in layers of 0.2mm, 4 shells and top&bottom layer of 1.6mm. Amount of Infill depending on the part, between 10 and 40%. Finished one top cover with openings for charging port, power switch an power indicator LEDs.

MS14-528-07.jpg

Link to comment
Share on other sites

Only two more parts to do, of which one is almost printed (@92%). I decided to paint the top section black. It would be really really nice to receive my tire and batteries sometime soon :)

MS14-528-09.jpg

 

MS14-528-08.jpg

Link to comment
Share on other sites

Okay, finally finished printing today - I had to do the last part in two colors as I was running very low on filament. Turned out quite ok imho. Now I only need to wait for my tire and batteries before I can have a ride. They should have arrived a long time ago, but hopefully I don´t have to wait for too long anymore.

P6213129b.JPG

 

P6213144b.JPG

Link to comment
Share on other sites

Here in Portugal I already saw some 16'' tires on shops, maybe they also sell 14''.
The batteries are hard to find, because the BMS is really important - the BMS protected a lot of times short circuits I did when connecting different boards and motors.

If you have a lab power supply you at least test the system.

Link to comment
Share on other sites

2 hours ago, electric_vehicle_lover said:

Here in Portugal I already saw some 16'' tires on shops, maybe they also sell 14''.
The batteries are hard to find, because the BMS is really important - the BMS protected a lot of times short circuits I did when connecting different boards and motors.

If you have a lab power supply you at least test the system.

I managed to find 16" tires here in Finland too, but no 14".  I ordered a 14" tire from China a long time ago, but they accidentally sent me an inner tube instead of the outer tire. The replacement has been on its way for 2 1/2 weeks now, so hopefully sometime soon. I can easily borrow a battery from my other EUC for testing, but I wouldn´t want to change a heavily used tire from one cycle to another just because of a few days.

The two batteries I ordered from aliexpress do have a BMS and I have also ordered two separate BMS circuits in case I decide to make my own batteries from separate cells. So I am starting with two batteries and will try to add more later.

One thing I still need to find are some of those small white connectors for the mainboard, my power switch has a much bigger connector. The buzzer also needs one.

 

Link to comment
Share on other sites

The mainboard attached to the dividing plate, which is inserted into the battery housing, leaving enough space for a battery. The other side can hold two batteries and there´s room for one more on the top. For that one, I will print a battery tray which will prevent it from sliding around.

IMG_20160623_150849[1].jpg

Link to comment
Share on other sites

Seems you are going for a path I already went. If the board takes the space for a battery, you can move the board and let the battery that is much heavier near the motor axis as possible.

Batteries on top of the wheel works but gives a more uncomfortable ride :-(

If you are looking to 4 battery packs, maybe you can do like my design but use 2 packs at each side instead. You design seems more larger anyway than my design.

Seems you are going for a path I already went. If the board takes the space for a battery, you can move the board and let the battery that is much heavier near the motor axis as possible.

Batteries on top of the wheel works but gives a more uncomfortable ride :-(

If you are looking to 4 battery packs, maybe you can do like my design but use 2 packs at each side instead. You design seems more larger anyway than my design.

Seems you are going for a path I already went. If the board takes the space for a battery, you can move the board and let the battery that is much heavier near the motor axis as possible.

Batteries on top of the wheel works but gives a more uncomfortable ride :-(

If you are looking to 4 battery packs, maybe you can do like my design but use 2 packs at each side instead. You design seems more larger anyway than my design.

Link to comment
Share on other sites

2 hours ago, electric_vehicle_lover said:

Seems you are going for a path I already went. If the board takes the space for a battery, you can move the board and let the battery that is much heavier near the motor axis as possible.

Batteries on top of the wheel works but gives a more uncomfortable ride :-(

If you are looking to 4 battery packs, maybe you can do like my design but use 2 packs at each side instead. You design seems more larger anyway than my design.

I agree that it would be nice to have two packs on each side, but the problem is that there is no other place to put the board as it needs to be placed vertically. I did not notice any imbalance with my generic, even though it has a battery on one side and the controller on the other. My design has two batteries on one side and one plus the controller on the other, so basically the same amount of imbalance. The fourth possible battery will be placed flat on top and as closely to the wheel axis as possible. It raises the total height only by about 2.5 cm.  It is not possible to use that same space for the controller and I do not want to have a separate enclosure. I don´t think that adding one pack flat on top will have any dramatic impact on overall balance as there are still three other packs which are located lower, so the center of gravity will shift only slightly.

Link to comment
Share on other sites

3 hours ago, electric_vehicle_lover said:

Ok and I wait for your sharing of experience when riding.

Yes, only one battery in one side seems to not be a problem - my girlfriend is riding his EGG EUC like that (because right now I just have 3 packs available - 2 packs for my EGG and 1 pack for her EGG :-)

I´ll report my findings as soon as I get to test it. It´s a bit frustrating to have to wait for a simple thing like a tire for such a long time... :D  I will also be starting with just two battery packs, but I wanted to have the possibility to easily add more without having to do any large changes to the construction. In addition to the two battery packs I ordered,  I´m also expecting two separate BMS units so I can make my own battery packs from separate 18650 cells at a slightly lower cost.

Link to comment
Share on other sites

An update - today, I received a package, which was supposed to contain my long awaited tire but... surprise, surprise... contained another inner tube instead. So I now have three inner tubes but no outer tire! I don´t know what to say...:wacko: Still no possibility to test my unicycle. However I managed to find the same tire size from an Ebay seller in the UK, which was advertised as a childrens´ mountainbike tire, but the size 14x2.125 was identical, so I ordered it. It has a rougher profile, but I don´t really mind since I often ride on gravel roads.  I took the fastest possible shipping option, so the tire should be here by the beginning of next week in case everything goes according to plan this time.  Hopefully it fits. Meanwhile, since there´s not much else to do, I am continiuing to work on my pedal extension project. First version is currently being printed, I´ll report.... And before you ask,  no, I don´t want to have pink pedals, I´ll paint them black later...

13563313_10154323521458921_1639296399_n.jpg

Pedal enlargements.jpg

Link to comment
Share on other sites

  Attached you will find the stl file for the pedal cover. The print turned out better than I expected - it really fits like a glove. The pedal cover will stay in place just by putting it on. No glue or other adhesives needed unless you want to. At least with the pedals with straight ridges that I bought from Mircoworks. The grooves in the covers will stick to the ridges on the pedal and prevent it from sliding. Just put it on and start riding... if you happen to have a tire ;)

@HunkaHunkaBurningLove

 

13563671_10154323939988921_1165728581_n.jpg

13565606_10154323939708921_1689952116_n.jpg

Pedal_cover.stl

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...