 | | Re: drawbridge
|
|
(...) I hope my bridge design spreadsheet worked okay for you. Your trusses look good! Nice work. Very nice! (...) I've hit a similar problem in planning out a crane. I've contemplated using two separate winches to lift the main hoist, but just like (...) (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
I just got through purchasing 4 rotation sensors for that very reason for my lift bridge ((URL) - in Creations). I will be adding the 4 rotation sensors and an additional rcx to my bridge sometime this year. Out of 32 motors, I could never get 2 (...) (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
(...) In my view one of the simpler ways is to shaft connect the two motors if you can... You can hide it if you have the sort of lift bridge that has an upper connection between the two towers. It may not always work though. (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
(...) Ok, here's my idea for a solution for a vertically lifting bridge. All you need is one winch connected to one lifting line. You also need one control line(running off the same motor but geared down 2:1). The lifting line goes up the first (...) (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
(...) I've thought of a simpler way of describing my system. Basically you have a rope stretched between two towers. If you pull the rope the span goes up, release it and the span goes down. The wire is connected to the lift span at both ends via (...) (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
(...) the length of the wire has nothing to do with the speed. the problem is that one motor, the first one on the line, is getting most of the power. the motor at 9v, 12v or 115v that doesn't mean thats the exact amount of power that it uses, it (...) (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
That might very well almost hold true (I am no expert) if your motors were hooked up like: [power]--------[moto...---[motor] (parallel circuit) But I have mine hooked up like: [motor]--------[powe...---[motor] (parallel circuits) I assume one motor (...) (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
(...) well since i was basing my theory of working with stereos and lights on my car, you have the uperhand...lol (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: drawbridge
|
|
(...) I believe your are right Steven, if two identical motors were connected in an identical way they would run at the same speed provided they had identical loads. But nothing in this physical world is identical and that is why stepper motors and (...) (22 years ago, 29-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Vertical lift spans (was: Re: drawbridge
|
|
Not sure where to chime in, so I'll jump in here. Regarding the lifting of vertical lift spans: I've built many of these over the years and my latest version (yet to be published on the internet) takes advantage of an engineering survey done on one (...) (22 years ago, 30-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: Vertical lift spans (was: Re: drawbridge
|
|
(...) OK, this is similar, but first take a walk down to the local auto repair shop and see if you can look at a 'cats cradle' type auto hoist. Here is my description. It involves one string to lift one end of the span and another string, which is (...) (22 years ago, 30-Apr-03, to lugnet.technic, lugnet.trains)
|
| |
| | Re: Vertical lift spans (was: Re: drawbridge
|
|
Well put Ben. I have seen Ben's steel bridge (and helped re-rig the cables to the pulleys after a minor anomaly), and I can attest that it is truely one of the finest LEGO bridges in the AFOL community, or in the world for that matter. It is very (...) (22 years ago, 30-Apr-03, to lugnet.technic, lugnet.trains)
|
