Newbie from NZ

[AndyUK]

Hi Richard

Have you considered long stroke linear actuators?

I suggest these because they're usually rated in terms of the force they can apply (which should be an easier calculation) and are often provided with 12/24V compatible systems which might be useful given the mobile environment. They should be cheaper than a ballscrew, because unlike a CNC you're not looking for a high degree of accuracy in this use case (1mm is probably close enough!).

The one disadvantage I can see is they might not be the quickest of options ;)

BW,
Andy

[Doddy]

Not to argue with the OP - just to ask you to review your statement: you say a hoist is awkward and dangerous - lifting 70kg into the boot. I'd suggest its probably the easier solution and can certainly be made safe. Awkwardness is more subjective.

Few solutions are going to "sit" in the boot - there's either going to be an awful lot of framework and counterweight, or you're going to have to bolt to the structure of the vehicle.

[AndyUK]

<Ignore my rant which missed the word hoist in the above post....>

[Doddy]

The point is that this is a one time thing to make a system which fits in to the back of a car, and then allows the user to be more independent.

Lifting 70kg in and out of a car boot is no joke for an able bodied adult male - I'm not even sure I'd be comfortable doing that alone, it's a big weight if you slip. Let alone when that's an awkward shape, and if the able bodied person who has to do it is a 50kg female, no chance in hell.

Sent from my SM-G950F using Tapatalk

We might misunderstand each other - the point I'm making is to manufacture a hoist, even on a sliding or swinging arm, is likely easier than a tail-gate lift type of system. I'm not suggesting for a second that manually lifting the OMEO is viable. Been there, tried it with similar (but heavier) weights and lost count of the number of lives I've lost.

[rjsutton]

Doddy
the hoists have to be bolted to the rear of the vehicle and when lifting the machine you have to put a cradle thru the handles then lift and rotate the chair at the same time. A major problem is you then have to tie the chair down in the boot which means reaching over and around and doing up ratchets etc . not easy for a person in wheelchair.
once the chair is locked to my forks that's it the mechanics do the rest.
My machine does in fact "Sit" in the back it has 2 simple metal straps which go behind the rear seat and secure to the rear safety belt anchor points. This is only to stop the machine "tipping" when fully extended out the boot.
also the width of the chair with outdoor kit tires is 830mm and a lot of normal suv wont fit that width wise as well as the hoist so must have the narrow tires which is a pain to change over ( change 2 wheels every time you want to off road!
My overall is 1000 and all the gear is clear of the chair which slides into a "pan" which is 850mm clear width so takes both sets of tyres.
Thanks For your comments

[rjsutton]

Hi Andy
thanks for the reply
Actuators can t work as the amount of travel is 900mm +- and most actuators are 2s + ? and i only have 900mm to fit it in
It cant stick out the front or back
I use an actuator to push the initial platform out the 400mm which works well.
speed isn't a problem but i think fully in to out needs to be 15-20 secs or we could all be dead waiting for it to arrive
thanks Richard