Zannu's Basher Rocksta

[Zannu]

So I decided that this would be a great rc to take on holiday (whilst sitting on a beach on holiday wishing I had an RC to play with) and when I got back and saw that the kit was on sale and to build the whole thing as stock (with LiPo and metal servo) for £20 less than the rtr version (That still does not include the LiPo). The next things I knew it was ordered and today it arrived. I used the standard transmitter, all in one receiver/ESC unit and standard motors. Then some nice metal geared and high power servos and a LiPo finish it off.

Ready to build everything:

 

And a while later:

 

Now rather than tale the easy route, I decided to try using a larger Lipo than recomended. The kit suggests a 350 mah 2s LiPo, but that does not sound like it will last as long as say a 850 mah 2s. And after careful consulting of sizes I decided I could just about squish it in. I had to cut the battery tray to let the wires out, and then the top plate so the esc battery connector could stick out the top, but it all works. I can still close the battery box and now I should have double the running time compared to stock. Seeing as all the connectors are still accesible I can also get several batteries and swap them as I use them, so there are no real disadvantages, apart from it breaking the waterproof seals, however I don't intend to be in the water, just on the rocks at the beach so it should be fine.

It fits, just:

 

The hole in the battery tray:

 

The other connector where it leaves the ESC case:

 

[Bix]

The more posts and info I see about these mini basher models the more appealing they are! [emoji1303]


Sent from my iPhone using Tapatalk

[Zannu]

Just now, Bix said:

The more posts and info I see about these mini basher models the more appealing they are!

 

Yeah, I had read about them a bit and having seen the kit on sale I decided it was worth it. I have spent just over £50 on this, but it shoudl keep me entertained for many years to come, and is the perfect size to put in a tin box I have and take wherever I go, like on a small plane where a 1/10 or ever 1/18 is impracticle.

The top speed is very slow, but hey, it's a crawler and it means there is more control than normal.

Once I saw it was on sale and added up the prices I decided it was too good an offer to pass up.

[WiLLiE]

Have you found any restricted movement with the battery wires coming out the box ?.

[Zannu]

10 hours ago, WiLLiE said:

Have you found any restricted movement with the battery wires coming out the box ?.

 

No, it is all fine. The wires don't get in the way of anything where they are. They can also tuck quite nicley under the rear of the body frame so they won't catch on anything.

[WiLLiE]

3 minutes ago, Zannu said:

 

No, it is all fine. The wires don't get in the way of anything where they are. They can also tuck quite nicley under the rear of the body frame so they won't catch on anything.

Ok thanks , I'll give them a look into , the other thing I've not seen yet is what and if the esc lvc will cut in at , I brought the small 350 mha batts and there quite a bit of room in the battery case .

[Zannu]

1 minute ago, WiLLiE said:

Ok thanks , I'll give them a look into , the other thing I've not seen yet is what and if the esc lvc will cut in at , I brought the small 350 mha batts and there quite a bit of room in the battery case .

I just looked at the battery tray dimensions and decided that this was about 2mm out on one side, but being the DIY sort of person I am thought I could make it fit. Sure enough it fits the case fine, just the wires cause an issue so I cut that grove. You also have to cut so the ESC wires will stick out the top so they will connect.

I don't knwo about the LVC either, but next time I run I will try with a lipo alarm as backup and see if it triggers somewhere before 3.0v otherwise I will have fun trying to fit a lipo alarm hidden somewhere within it.

[WiLLiE]

7 minutes ago, Zannu said:

I just looked at the battery tray dimensions and decided that this was about 2mm out on one side, but being the DIY sort of person I am thought I could make it fit. Sure enough it fits the case fine, just the wires cause an issue so I cut that grove. You also have to cut so the ESC wires will stick out the top so they will connect.

I don't knwo about the LVC either, but next time I run I will try with a lipo alarm as backup and see if it triggers somewhere before 3.0v otherwise I will have fun trying to fit a lipo alarm hidden somewhere within it.

 

Yes I was thinking that myself with the lipo alarm , checked earlier and the lipo was at 3.75 , after running for a while , forgot to get an estimate on the length of time in use , just to see how long it will run before batt change .

[Zannu]

28 minutes ago, WiLLiE said:

 

Yes I was thinking that myself with the lipo alarm , checked earlier and the lipo was at 3.75 , after running for a while , forgot to get an estimate on the length of time in use , just to see how long it will run before batt change .

Ok, well once I have used this for a while I can let you know what the battery life is like with the 850 and see if it is better.

 

[Zannu]

So I gave it a quick test to estimate battery life. I only ran it for 10 minutes, but I tried to keep it on full throttle a lot more than I probably would in actual crawling. I found that it only went down by about 0.1v, which would suggest that my LiPo will last for about 3.5 hours if I run it from 8.40V to 6.20v (4.20 to 3.10 on each cell).

That sounds way out to me, and is probably completly incorect, however it would be amazing if I really could get that sort of run time. No more spare batteries for a day out. I will update you as I find a more accurate estimate, because as I say it was only for 10 minutes and not quite typical use.

[ghazghul]

1 hour ago, Zannu said:

So I gave it a quick test to estimate battery life. I only ran it for 10 minutes, but I tried to keep it on full throttle a lot more than I probably would in actual crawling. I found that it only went down by about 0.1v, which would suggest that my LiPo will last for about 3.5 hours if I run it from 8.40V to 6.20v (4.20 to 3.10 on each cell).

That sounds way out to me, and is probably completly incorect, however it would be amazing if I really could get that sort of run time. No more spare batteries for a day out. I will update you as I find a more accurate estimate, because as I say it was only for 10 minutes and not quite typical use.

 

LiPo voltage / capacity isn't linear... voltage will stay pretty high for most of capacity and then drop at the end.  Initial drop will be based on load and then it tends to hold at that until capacity is getting exhausted.  It what makes them so good to use as you get consistent performance but is also what makes the cutoff important!

Edited August 31, 2017 by ghazghul

[Zannu]

8 hours ago, ghazghul said:

 

LiPo voltage / capacity isn't linear... voltage will stay pretty high for most of capacity and then drop at the end.  Initial drop will be based on load and then it tends to hold at that until capacity is getting exhausted.  It what makes them so good to use as you get consistent performance but is also what makes the cutoff important!

I know, and that is why I suspect it will run out far quicker. I just wanted to get a rough idea of what it may be like. There is a reason why I want to do a full run and time it so I know the battery life.

[Zannu]

I now have a much better and more acurate estimate for the battery life, having just had a bit more of a play with this great little crawler. I also made a few other interesting discoveries which I will share.

Rather than using voltage which I know is fundamentally flawed I tried using my smart LiPo checker that also gives a percentage of capacity left. I only ran for 7 minutes before the LiPo was flat, showing this time I was clearly at the great drop in voltage. Judging by percentages with my LiPo checker my battery ought to last around 70 mins, or just over 1 hour. Again this was running it pretty hard for the test, so I suspect the reality may be a bit more, which I think is very good. I will still get a second and maybe 3rd battery to take on holiday but they ought to last a long time.

I would also suggest people using the stock ESC to use a LiPo alarm as well. I tested the built in function this time, keeping a careful eye on the cell voltages. It finally cut out when the cells were at 3.17 and 2.94 volts. This leads me to assume it cuts out when the main voltage reaches 6.1V. For me this is a bit low, and I like to cut out when either cell touches 3.20V so I will make sure I use a LiPo alarm, although it is not the easiest to fit into the chassis, I found just above the ESC there is space and my balance lead will just about fit. I will add pictures sometime over the next few days.

[nr73]

Just ordered me one of these from HK. I've not been near my Scout for a while and with moving house soon all my RC kit is boxed up.  This little bad boy should help give me a fix regardless of the weather. I've gone with some 350mah zippys' for now but may well mod it to take one of the 850mah you've managed to squeeze in at some point.

[Zannu]

17 hours ago, nr73 said:

Just ordered me one of these from HK. I've not been near my Scout for a while and with moving house soon all my RC kit is boxed up.  This little bad boy should help give me a fix regardless of the weather. I've gone with some 350mah zippys' for now but may well mod it to take one of the 850mah you've managed to squeeze in at some point.

Sounds good. I have not really used mine much for now, but I never intended to whilst at home. My idea is when on holiday I can take this with me and play on the beach/rocks rather than just sunbathing (Which I can't stand, I have to be doing something). The 850mah LiPo certainly lasts a while, but it depends on what you want. It also stops the battery compartment being waterproof so there are reasons not to do it.

Enjoy it

[nr73]

Well it landed today and it's been all kinds of fun, the kids have been making assault courses in the lounge for the basher to tackle. Had to strip the rear diff as it was graunchy from the outset. Two of the teeth were factory stripped [emoji2]

Replaced those and now it's smooth, will replace with metal gears soon anyway.

First snag though, the rear servo arm has just snapped. Servos are one thing I know absolutely zero about, and I can't see any spares listed specifically for the rockstar so I guess I'm into having to decipher what size, how many splines etc? If anyone can shortcut me to a spare it would help.

Aside from that it's awesome. Seem to be getting a good 20-25 mins from a 350mah too which is easily good enough.

Sent from my SM-G935F using Tapatalk

[Zannu]

Sounds good. It is perfect for that sort of indoor bashing, although I do plan to use mine at the beach. That is strange, mine were fine and had no issues with any of it.

 

How do you even snap the servo arm? If you can't find spares listed then you may struggle a bit. Best bet may be to count the teeth on the servo gear and find a coresponding arm for it.

That is pretty good for  a 350mah, makes me hopeful to get an hour out of mine.

[nr73]

Yep, the servo arm snapped during an extreme mission over the conservatory sofa. I use the rear steer a lot.

I can get 35-40 mins from an 800mah on my maverick scout, so I think you should comfortably get well over an hour on the basher..

Sent from my SM-G935F using Tapatalk

[Zannu]

20 minutes ago, nr73 said:

Yep, the servo arm snapped during an extreme mission over the conservatory sofa. I use the rear steer a lot.

I can get 35-40 mins from an 800mah on my maverick scout, so I think you should comfortably get well over an hour on the basher..

That must have been very extreme crawling to snap the arm.

Wow, in that case I may get far longer. I wil have to see sometime, but won't be for a few weeks I don't think. I wanted the large battery so that I can take it out for the day and not have to worry about changing LiPo's or it running out. (As they are slower than walking I will carry it between places and when we settle down on a beach and everyone else is sunbathing I can go off and play then, so an hour should be enough)

[nr73]

Yes it was beyond extreme. Managed to get over the scatterback cushions and over the kids toy collection.

 

I gave up looking for a suitable replacement servo arm, the splines are so small it would be nigh on impossible to count them anyway so I gave in and ordered a couple of metal geared Turnigy micro servos to replace them with.

[Zannu]

5 hours ago, nr73 said:

Yes it was beyond extreme. Managed to get over the scatterback cushions and over the kids toy collection.

 

I gave up looking for a suitable replacement servo arm, the splines are so small it would be nigh on impossible to count them anyway so I gave in and ordered a couple of metal geared Turnigy micro servos to replace them with.

That does sound a bit beyond the capability of this crawler! No wonder you broke something.

 

Very good idea. As I got mine as the kit I was able to have the metal servo's from the beginning. At least you should also then have a few spare arms in case of damage to the new ones! Let me know how it goes once they have arrived

[bertberr]

Did you ever run this with the stock plastic gears, or just go metal from the get go? Like the idea of one of these for winter inside fun, but heard they really need the metal gears, and they're over 20 quid delivered for both sets...

[Zannu]

I have still got the plastic gears in there, and not had an issue. I have only run my Lipo through it twice or 3 times, so not used it that much, but everything is fine and still working as it is.

[nr73]

I replaced both servos last night with Turnigy TGY-9025MG metal geared servos. For now I've used the double arms, they're much beefier than the stock arms so I don't expect any more problems. The servos are a fair bit stronger than the stock ones, and turn noticeably quicker as you'd expect. For £4.15 each it's a no brainer!

 

Also comfortably getting half an hour out of a 350mah lipo.

 

So far I've replaced one plastic gear in the rear diff that seemed to have had two teeth stripped from the moment I unboxed it. As long as you understand not to drive a wheel into a wedge or an obstacle where the wheel has nowhere to go, it should be fine for a while on the plastic gears.

 

 

 

 

 

[Zannu]

3 minutes ago, nr73 said:

I replaced both servos last night with Turnigy TGY-9025MG metal geared servos. For now I've used the double arms, they're much beefier than the stock arms so I don't expect any more problems. The servos are a fair bit stronger than the stock ones, and turn noticeably quicker as you'd expect. For £4.15 each it's a no brainer!

Also comfortably getting half an hour out of a 350mah lipo.

Sounds good. It can be suprising how much difference things like servo's will make to the performance of something like this. Those arms look pretty similar to the size I was using. If I were you get a craft knife and cut off the side you don't need to make it nice and neat.

Super, so I should get well over an hour.