A new life - irving reborn after near fatal accident

Thought it about time I updated this thread...

We we've moved back in, though the builders are still here finishing off. About another month, and a huge snagging list - nothing major so far though. Gone way over budget, about 30%, so new workshop on back burner for now.

Trying to source automatic door openers for double front doors... stupidly expensive even on Aliexpress! After all, its just a motor/gearbox and an arm and some crude position/current sensing for end points and obstacle detection... can't be that hard to make one :whistle:

Hi Irving, glad to here that you are getting there now with your house mods, and that you have moved back in. Are you at home full time now? I know what you mean about cost overun and snagging lists - I bet you are well on top of the latter, and that the builder will love you for it!!! You are dead right about the cost of door openers, we are looking into something similar for driveway gates, but it will probably be a non starter because of the costs. As you say, not rocket science, but astronomical prices. Anyway good luck with your new life at home - the new workshop will come I am sure. G.

Designing one as we speak, but trying to get head round force diagrams to figure arm sizes and shaft torques...

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Originally Posted by irving2008

Designing one as we speak, but trying to get head round force diagrams to figure arm sizes and shaft torques...

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Much too technical for me, but I know you will make it seem easy!!!G.

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Originally Posted by irving2008

Designing one as we speak, but trying to get head round force diagrams to figure arm sizes and shaft torques...

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Good to hear you've moved back, I know the feeling living out of cardboard boxes after I had to move out because of Death Watch Beetle...
As for the automatic door opener just get yourself a PA (blonde 20's) that will open more doors for you.
Mike :)

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Originally Posted by longy

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As for the automatic door opener just get yourself a PA (blonde 20's) that will open more doors for you.
Mike :)

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I've got two, neither are blond tho... :) but I want to be able to go out to shops etc on my own....

I know that feeling of wanting to be independent. Irving try your local shop fitters they might be able to give you a good price for supplying and fitting the doors. Or maybe twist there arm for some info on loads etc. worth a try may they can always say no, but if you don't ask you'll never know.

The doors I have, complete with motorised locks. Its the door openers I need...

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Originally Posted by irving2008

Trying to source automatic door openers for double front doors... stupidly expensive even on Aliexpress! After all, its just a motor/gearbox and an arm and some crude position/current sensing for end points and obstacle detection... can't be that hard to make one :whistle:

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Stepper motor, ballscrew, driver, power supply, couple of microswitches, Arduino... can't be that hard to make one :whistle:

hard part is the motion detection (without detecting he door) must ensure that any detection either stops the motors & goes free or smart enough to know which way to move (open or closed as required to release...and limiting the power if someone or something gets trapped behind or between

actually the obstacle detect is the easy bit... just need to monitor the current draw by the motor over a few open/close cycles to learn the profile... any deviation from that is a 'stop & back off, wait, try again' cycle (exactly how my lift doors do it).

The harder bit is working out the actual mechanism. Standard units don't use ballscrews, just a motor and gearbox turning a shaft and an articulating (low torque/more complex engineering) or sliding (simpler, but higher torque and higher maintenance/wear) arm.

Sorry Irving, I had no idea that you had an accident, very sorry to hear of it.

It may be worth a look in the Hafle direction, they have a good range of gear and some good drawings. Best of luck with the project and the workshop once you get to that.

All the best

Suesi

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Originally Posted by irving2008

actually the obstacle detect is the easy bit... just need to monitor the current draw by the motor over a few open/close cycles to learn the profile... any deviation from that is a 'stop & back off, wait, try again' cycle (exactly how my lift doors do it).

The harder bit is working out the actual mechanism. Standard units don't use ballscrews, just a motor and gearbox turning a shaft and an articulating (low torque/more complex engineering) or sliding (simpler, but higher torque and higher maintenance/wear) arm.

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How about this for a Heath Robinson solution...

Door is closed by a standard door closer.

Door is opened by string wound around a bobbin on an electric motor.

I haven't had time to look at interference between opener and closer but it should be possible to work around it.

Apologies for the dreadful drawings...

http://www.mycncuk.com/attachment.ph...id=14482&stc=1http://www.mycncuk.com/attachment.ph...id=14483&stc=1

lol, don't think my wife would accept a heath-robinson approach! having said that, I did look at a cable pull design, but the door closers don't give a positive closure against the draft proofing for the multipoint locking to engage, so needs to be an active pull closure as well. also needs a clutch/freewheel to allow manual opening of the door.

Designing a linear motor, in an arc shape, to embed in the floor would be a fun way to do it ...

The attractive forces between the armature and stator could be problematic (i.e. very rigid hinges required), but perhaps it could be a core-less motor to mitigate that. Line of magnets in the floor and a couple of coils on the door perhaps...

If it's possible to access directly beneath or above the rotating centre of the door hinge, either from the top or under the floorboards you could install an extension shaft to the top/bottom of the door that is in alignment with the hinge axis with a geared wheel, and drive this with a worm(and suitable motor) the motor housing could be actuated to swing the worm out of engagement for manual operation.
Not had a windscreen wiper motor to bits in a lot years but if memory recalls they might have some usefull bits, if it would produce the required torque.
Regards
Mike

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Originally Posted by Jonathan

Designing a linear motor, in an arc shape, to embed in the floor would be a fun way to do it ...

The attractive forces between the armature and stator could be problematic (i.e. very rigid hinges required), but perhaps it could be a core-less motor to mitigate that. Line of magnets in the floor and a couple of coils on the door perhaps...

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Fun but not practical with an engineered wood floor.., the hinges are easily up to the job. Equally you could have a curved section of r&p and a motor attached to the door, but aesthetically its crap...

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Originally Posted by mekanik

If it's possible to access directly beneath or above the rotating centre of the door hinge, either from the top or under the floorboards you could install an extension shaft to the top/bottom of the door that is in alignment with the hinge axis with a geared wheel, and drive this with a worm(and suitable motor) the motor housing could be actuated to swing the worm out of engagement for manual operation.
Not had a windscreen wiper motor to bits in a lot years but if memory recalls they might have some usefull bits, if it would produce the required torque.
Regards
Mike

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neither is possible, but such units do exist. They use a motor plus gear train, often a multistage epicyclic. Manual operation is achieved with a slipping clutch or just driving the motor in freewheel, so no worms..