|
Hi Lawrie,
tracked down the email of Phil Nuytens re building
an ejectable manipulator.
It's at the end of this email.
Sounds an
interesting control system, be great to see how it
progresses.
I'm controlling most things on my sub with a "Play Station 2"
controller.
I picked up a PS2 input / output converter from a robotics site. This
converts the digital
signal to analogue & outputs on about 16 terminals. Four terminals are
pulse width modulation,
& all need relays. However I'm putting in over ride switches in case it
fails.
Regards Alan
Hullo, Joe:
> Just back in town, so. . . manipulator arm jettison design(s): On > hydraulic/pneumatic/water hydraulic actuated arms, first determine number > of functions - 6 function is usual (1. shoulder yaw/ rotate, 2.shoulder > extend 3.elbow extend, 4. upper wrist extend, 5. wrist rotate, 6.jaw open & > close.) 7 and 8 function are not unusual - about the least you can do any > effective work with is 3 (shoulder extend, elbow extend, jaw open& close. > When you know how many functions, then you know how many hydraulic lines > you will require from the pump and back to the reservoir. Then determine > where you want the arm to break (jettison) . Wrist is easiest, but affords > least protection. Entire arm is best but requires most elaborate and > largest jettison section . > Most of you will be familiar with hydraulic or pneumatic QD's > (quick-disconnects). When a female sleeve is pulled back and tension is > placed on the line or the opposed parts, the QD separates - even under full > pressure or zero pressure. So . . . saw your arm off at some point where > you want it to disconnect - weld or bolt a plate to each cut end of ,say, > the 'bicep" section (midway between the elbow and the shoulder. Make the > plates (round or square) bigger than the arm diameter - so that you have > about an inch and a half flange all around the arm 'end'. If you put holes > in the flange portion of the plates, you could bolt the arm back together. > But, instead, drill and tap (thread) the plates with as many holes as you > have hydraulic lines downstream of the plates/flanges. On one side of the > plate flange, screw in pipe- to- hydraulic line (female nut) nipples - > these will join to your hydraulic hoses. On the other side of the same > plate, install the same number of, say, female QD sleeves to pipe thread > fittings. Do the same with the other flange, but on the side facing the > sleeve fittings, thread in the male snout/nozzle of the QD. Then make up a > 3rd plate that is the same diameter as your threaded plates (if your arm is > three inches in diameter, for example - you would have a 7 inch ID by 3 > inch OD plate. Drill out and make this plate so that is attached to the > female sleeves of the QD. (Buy QD's that have a narrower 'waist' in the > middle of the sleeve for this purpose) Put a short hydraulic cylinder > between the threaded sleeve plate and the sleeve actuation plate. run a > hydraulic line to this cylinder and run the other end to a > manually-operated hydraulic hand pump (wobble pump) in side the sub cabin. > If the arm gets stuck, open the bulkhead valve on your hydraulic > through-hull and pump the arm off. > Sounds a bit complicated, but there's nothing to it. > If you use a valveless water-hydraulic suck/blow manipulator actuation > system, the manip detent is even easier. But . . .time for bed - more > later. > Phil ----- Original Message -----
|