Wheelchair Trike - 12v motor for tailgate operation

[Pringle]

​Hello to all,

Name is Alan Stanley, i have been a paraplegic for 27 years

I am rebuilding a wheelchair accessable trike i have purchased to be a fun runabout for me

the whole thing is stripped at the moment and it got me to thinking of a modification i could make to it.
Currently it has a hinged tailgate which drops down to allow access into the 'cockpit' of the bike, this gate is manually operated by a lever and rod attachment to the tailgate, the lever is mounted inside the cockpit, and to be honest, its a bit basic and does get in the way sometimes as the handle get entangled with the wheel spokes.

as the bike is stripped, i thought of adding a 12 v gear motor, with a cotton reel type attachment, this will carry a cable to the tailgate, hook this up to a for/rev switch and i should have a remote for dropping and raising the tailgate.

the tailgate currently weighs about 30kg estimated, and will need to travel through about 100 to 110 degree's.

Could any of you experts out there help me with advice for what type of motor i should use. there is so many out there of differing types and speeds it can get more than a little confusing.

any suggestions would be appreciated .

if you would like to get an idea of the trike, then pop along to

http://www.nippi.co.uk

many thanks for any help offered

All the very best
Alan

 

[PEG]

Hi Alan,i think i know the principle of what you want to achieve. I guess for such a basic addition,you will not want to be buying a load of new actuators,etc. You will want it a controlled operation in both directions,which gets dubious if you are using gravity on cable lower,also without an additional locking method,you will rely on the same,thin bowden cable,for keeping it shut. I think at 30Kgs,it would require a robust electrically operated device,i have utilised 12v and 24v motor window actuators for lighter duties,but have had success with electric seat adjustment kits. Taken from a old,Japanese 4x4,for example,it has both the power,and a slow,geared speed. This could be mounted where suitable and operated by rod/quadrant or similar. Don't forget to build some hysteresis into the connection between motor/gearbox and ramp. This could be bi-directional springing on the control rod,or sprung centered sliders,or when you lower the ramp,and load up,the increase in weight will act directly on the mechanism,grossly in excess of its intended capacity. Limit switches or motor load cut-outs can be used on closing,but this cannot be used in the lowered position,as this will alter with terrain. I realise this is a personal project,but don't miss relays,watch pinch points in mechanism,and don't let anyone tell you "...It can't be done..." Good luck,fella.

 

[gnuuser]

screw type linear actuators while slow are a lot more robust and can handle a lot more weight.
using a pendant similar to what you would find on an electric chain hoist , limit switches and relays you can do it
good luck to you

 

[PEG]

Yep,linear actuators are simple and powerful,maybe a little too much so in this instance. The last two i fiddled with,one was on an electric gate,the other was the tipping "ram" on a small quad trailer. If one came up,it could easily be adapted,although to buy new would be expensive. I had a peep at the Trike,on their webpage,look plenty of room for adapting,what looks like a very simple hand-lever affair,for raising the ramp.

 

[Darkwood]

Hi Pringle welcome to the forum and its really encouraging to see someone with your restrictions not letting it burden your outlook, the reason I say this is because my uncle spent most of his life as a paraplegic after a car accident in his teens (sadly passed away now) but he never tried to enjoy his life after the accident and became much a recluse against all the family efforts to try give him as normal a life as could be expected.... It would have been so encouraging to see him have a hobby or enthusiasm that you possess with your little fun project and wish you all the best with your project although I can't offer any advice as its not my area... :stooge_curly:

 

[Pringle]

Well i am a bit gobsmacked, it is great in this day and age to see people give freely of their knowledge, i really do appreciate the replies from all, -
Yes Darkwood, i have seen it myself, people can become very depressed with life when something like this hits them, but having a family to see to, and two youngsters to keep you motivated and on the up, i have managed better than some with dealing with the day to day issues of wheelchair use, and hope to continue to do so.
now to it.

I have also been looking at linear actuators, maybe a 750nm or even a 1225nm was suggested (company called Gimson Robotics if i remember) a 200mm or 300mm stroke length but i was begining to confuse myself with the jargon ;-)

Some models had potentiaometers built in, does this allow for the actuator to stop should it hit a heavy load point?

and also i was concerned as to how to mount it, as there would be some radial movement as the gate was lowered and raised, my thoughts were to attach the one end of the actuator to a point on the frame, single fixing point that it could rotate around as the gate was lowered, and the other end attached directly to the gate frame.

The company also supplied a control box for switching the polarity as well as a wireless reciever so that it could be operated from a keyfob. i think the total costs were about 100 quids.

this mod is being done along with some other bigger upgrades to the bike (trike) as i have travelled about in it and found the little 125 engine just not man enough to carry me and my chair up inclines without holding up traffic, so now it's a 200cc, with drive train mods added, final drive gear mod and a fancy sports exhaust, bodywork fix up and a spiffing respray. may not get it completed by end of this summer, but will sure be ready for the next one.

Just thought it would be a nice to have instead of battling with a manual lever setup, just seems a bit jerrybuilt to me.

again, many thanks for all the advice here, it sure does restore you faith in people when something like this happens.

All the best and will post again soon
Alan

 

[Darkwood]

Some of the point you touched on are within my area like linear actuators and pot's now its all dependant on the control set-up but the pot's could be used for anything from speed control to actuator distance travelled in operation to name a few you would need to relate to the manufactureres guide.

Basically a potentiometer is a variable resister and the position of it can be used to change a voltage or resistance value to a monitoring device - what this is then translated to is down to the designer, as i guessed it could be operational speed of the actuator or distance travelled etc etc.