A good way to make a stiff shake free hinge hinge is to start by welding a piece of steel strip onto the side of a short length of tube producing a P shape body. Then force a piece of slightly longer thick wall "rubber" tube / hose into the tube making a pivot bearing and slide a suitble size pin though. Two or three units per hinge according to duty and taste. Put suitable sized washers between the rubber overlaps at the ends of the tube so you dont get rubber to rubber contact which will bind things up rather. Sqidge the bits slightly together before mounting. Maybe put threads on the ends of the pin and use nuts to make a controlled assembly before fitting. This style of construction provides a bit of vibration isolation, always handy on a motor mount, and is shake free if the pin is made a push fit in the hose. It will never be quite as free moving as a common metal hinge but the stiffness in rotation can be adjusted by varying the size of the pin from quite free to pretty stiff. In many applications, like your motor mount, a stiff hinge is better as the darn thing stays put whilst you bolt up the fixing strap or whatever. Use a bit of red rubber grease on the pin and washers.
For a tool rest you'd need to make it very stiff and arrange some way of clamping independant of the hinge. Possibly using a thick wall on the tube bit and cutting the rubber a bit short with a through bolt as the hinge pin which could be tightend up to lock things would work. That said I'd prefer two fixings so amke the hinge very stiff and provide as second bold working in a slot on the tool rest proper to set the position.
I've made a fair few over the years steadily eating into the stash of I' (nominal) iron water pipe pulled out when we re-plumbed in copper around 1970. Car heater hose for the tube, 1/8" to 1/4" thick strip for the ears depending whats in the shorts box. Inch to inch half wide with 1/8" and a bit (real precision job this) overlap each end seems to work OK. Anything longer makes pushing the hose in a right pain. I just use separate P units on the two parts rather than make proper hinge units. Works OK.
The force tube in a hole with some overlap and washers on top does quite well for shop made vibration isolators too. Better at high frequency buzz than lower frequencies. Ideally done with the hole in a dead material such as plywood.
Clive.
Edited By Clive Foster on 16/08/2015 10:55:34
Edited By Clive Foster on 16/08/2015 10:56:10