Electric Car Project and racing in 1-5th scale

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Postby revup » Mon Feb 22, 2010 2:00 pm

edited
Love many, trust few, paddle your own canoe.
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Postby revup » Sun May 02, 2010 10:43 am

Ron In Holland has asked me about a 4x4 project he wishes to do and convert to electric off roader and also about the slipper clutch and when it engages etc…

Firstly. As most of you know, all smaller electric scales are direct drive when electric. I tried that and tried all sorts of ways to avoid the car sitting there whilst the wheels just spun on the tarmac. Electric motors, unlike their gas cousins give you their full power whether you have then doing 10 rpm or 30,000 rpm. The cars we use are 9 kilos weight and more. That is a heck of a lot to start rolling compared to a small 1/10th at about a tenth the weight. Then the running gears are under more strain. Having direct drive also tends to wear the motor out quicker as it is also being used to brake the heavy 9 kilo car. So all sorts of reasons to think of a different way.

Enter the slipper clutch. By having a unit that just bolts onto the existing mountings with no changes required is both simple, clean and easy to do and a lot less cost as well. Also be having a clutch applications like Ron’s where to is on rough ground will allow less forces being applied to the gears and differential and so on. This also applies to track cars but in not so pressured situation. It also allows the engine to disengage from the drive train under braking so any braking of the electric motor is not wearing out the motor and the force is being applied to where it is designed to do, the brakes. ( I have gone to four channel system which allows the motor and rear brakes to be separately controlled thus making set up, ABS and other features to be easier to do and less wear and tear on the motor). So by having a slipper clutch to get the car moving we give it a few thousand rev spread to fully engage thus softening the torque impact and less strain on the motor and transmission train from a standing start. The motor then has it’s life prolonged and extended as well as the gears and differential.

The beauty of all this is that if you wish to use electric all you have to do to your existing car is take the motor out, bolt the electric on in it’ place and remove the fuel tank for where the batteries go. Again less cost to you.

Just to digress a little from Ron’s question before I come back to it, most of you will think the LiPo batteries are a horrendous amount. Not any more. When I started this project over four years ago the first pack (actually twin pack) I bought cost me nearly 400 UK pounds and then they were only 3200mAh sets. Fast forward and both Paul J and myself now buy direct from China and the power output has gone up to 6000mAh and the price down to just over 100 UK pounds for two packs that give us 12000mAh and a run time of 30 minutes (dependant on gear ratio and track size). These batteries will do up to 100 charges before they loose capacity by 5-10% (then you use them for practise etc.) That is your fuel for a few years dependant on how many times you charge them and how you look after them. The way the Chinese are going we are told to expect 8-10,000mAh packs within 12-18 months! I have also been given an experimental motor from Pletenberg that has a soft spread of torque due to the way it is constructed and gives 1000rpm for every volt put through it so 28 volts gives 28000 rpm. You want to go fast? Due to a health issue and the poor winter we have just had I have not been able yet to try it but anticipate that during May I will and I will report back to you all my finding.

Back to the question. Some of you will remember Rob of ALRO Racing in the UK. Well Rob has moved premises and bought and industrial CNC machine. I went to him for him to design a clutch housing to mount the motor to that also bolted onto the clutch and primary gears. We discussed clutches and within hours Rob had sent me (before I even got home!) the design of the housing and an idea for the clutch. This idea was to make it so that easily available clutch shoes can be bought and replaced. Yes, the shoes are the FG F1 four shoes. So within a few days I had his machined from solid alloy billet the housing and clutch. Popped in a set of shoes , bolted on the motor (Rob can centre drill the right holes to suit your motor), the clutch was on (this is a 6mm centre but smaller and larger ones can be done) and I bench tested it. Perfect! So there you have it all done and dusted and easy to do. Just waiting for the Doctors all clear and I will be down at the Halifax track to do some testing.

Together with Daz, Rob Lochier is the moderator of this Forum so contact him at
rob@alroracing.com

I also want to see motor temperature before we get Rob to machine heat sink rings to go round the motor but that may be for the future.

Finally to Rob in Holland. I fitted an electric motor to a Carson Gas Devil 4 x 4 stadium truck and it was brilliant. The only downside was the body shell stood so high it gave no protection for the insides if I had run it on mud etc but it worked just fine with the clutch.

I hope this answers Rob’ question and more but do remember this is an ongoing topic and project so as we start racing again we will give you further updates.

Paul J has his Mini converted and at Halifax the other weekend he tells me he had A GRP on the front and C GRP on the back and got 20 seconds lap times. By his own admission Paul is not a top driver so 20 seconds is pretty good and he came away smiling he tells me.
Love many, trust few, paddle your own canoe.
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Postby Just_a_BRCA_Member » Sun May 02, 2010 11:48 am

Hi Chris
I am now on mark3 of my mini battery box etc
i will post some pics on here when i have it all right.

trever K did a lot of driving on the Saturday all i did was fix the Car
I started off with 38 sec laps and got that down to 28 sec laps with a bit of tweeking and car settings
Trever did the 20 second laps and he says that with a bit more tweeking it will do 19's.

This project is now gathering pace as i am now been sent a few more bits to try including a quad lipo charger 2.4G battery testing systems.

so we shall see
i will be doning all the BRCA large scale meeting as well as all the Wombwell series meetings.
So see you all soon
Paul
Just a BRCA member now
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Postby Radical Ron » Sun May 02, 2010 1:34 pm

Great info Chris! :mrblue:

Still waiting on parts to convert to 4x4, should arive this week. After that I'll have a good look at what to change etc. In the mean time, I'll send Rob a mail for some information on the clutch and maybe discus some custom parts needed.
Ron v D
I'm not totally useless, I can be used as a bad example.....so don't blame the Dutch guy!
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Postby revup » Tue Jun 01, 2010 2:34 pm

Those of you who have followed this thread and even got into electric racing will realise that up until very recently we only had enough run time for 15-20 minutes at best.

Paul and I have sourced new Li Po's direct from China and the news is that very soon to come are 6000 mAh batteries. So run parallel these will give 12,000mAh of use which equates to 20-30 minutes run time. This is so close to the gas boys and the news is that later this year 6500 and even 6800mAh sets will be available which takes us to over 30 minutes run time. Paul can get these LiPos for anyone wanting them at around £100 a pack landed and duty paid. Considering that three years ago I was paying £200 for a pack at only 3200mAh this is fantastic stuff. The packs should last over three years so there you go.

One of the main problems with those of you new to using Li Po's is the 'overuse' of them in pushing them below 3volts. I have used all sorts of little gismos to help me spot this happening on the track and all were OK in their application but........Help is now at hand. Paul already sourced this from Honk Kong (See http://www.hobbyking.com/hobbyking/stor ... duct=10343 ) and mine is on the way so this is now a thing of the past with telemetery units to protect the batteries.

One final thing. I have negotiated with Plentenberg a small discount on their motors. Anyone interested can get them through me and you pay exactly what it costs me, no extra added on. Rob has the CNC images on computer for back plates and clutches and I am sending to him a copy of a heatsink for the motors and a rear mounting to the chassis. We keep moving forward.

Chris
Love many, trust few, paddle your own canoe.
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Postby Selwa » Sat Jun 26, 2010 3:48 pm

Thinking about doing this with one of my Elcon Cleons. Seems a bit pricely right now though. Plus most of the "good" motors and ESC seem to come from Europe too. :o
1/6 Elcon Cleon x 2..... soon to be 3.
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Postby revup » Sun Sep 19, 2010 1:49 pm

Some of you will already know that just after the Euros in the UK last year I suffered illness. I appear to have got over it but it was a wake-up call to think carefully about what matters most in life.

I have been involved in Large Scale since 1986 and three of us set up the rules that you race in EFRA with and also in IFMAR. What with a Magazine for 8 years, trackside reporting and videos I was heavily involved but no more, I have retired.

The electric project has been passed to Paul Jenkson and I am pleased to say after all the years I have spent getting this off the ground that Paul will be the one bringing it to fruition. A full blowed electric 1/5 class will be in operation in the UK next year and as such I have passed car and contacts on to Paul so that he will administer the whole thing. Paul is already buying batteries direct from China factories so those prices have plummeted whilst power output has trebled. I wish Paul great success for the future of this class of racing so if you have any queries please address them to Paul please.
Love many, trust few, paddle your own canoe.
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Postby RcTek » Sun Sep 19, 2010 2:03 pm

Enjoy it Chris :)

Thanks for all your efforts to promote radio control.

Daz
Hmm...
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Postby revup » Sun Sep 19, 2010 3:28 pm

Thanks Daz
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Postby akouk » Sun Sep 19, 2010 5:27 pm

Hi Chris!
Your reviews & projects were always useful and enjoyable to read. Glad to hear you're doing well!

Take care,
Antonios
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