Emergency brake

Thanks for ideas.I remember when I was car-mecahnican I find that the windscreen - wipers had an electrical brake. In off position the + on the el.motor the viper got ground, and the induction/el.production from the motor stopped it momentary. I was a electrical brake. S.E.V. Mashall had a intern brake from the metal around the anker/rotor.Interesting if av condensation can make a brake? May be combined with some rectifiers ?
 
Last edited:
Torbo said:
.Interesting if av condensation can make a brake? May be combined with some rectifiers ?
Click to expand...

Oh it would have to be charged up to some DC value with some rectifiers. I already have everything needed; caps, diodes... time however is always in short supply. Anybody got a device to slow the clocks?

If I come up with something workable I'll post it.

Mark
 
Wery good! With DC arrangement it is also easy to make regulate the speed of the motor. Im wondering of to set a few big rectifiers i serie with one of the intake clamps, an ground them i off position, and have a open circuit in on position?It is easy to tray. Test circuit:Start the motor and stop it, while rotating I can check that the speed will be redused? Som other ideas would also be interesting?
 
Unfortunately the DC, applied to an AC motor, can only serve to brake (break :) ) it. A variable speed DC motor is a completely different device entirely.
 
The emergency stop is working very good, and is very stable! I was thinking of to put a DC-generator and put the + to ground when stopping.But it take some place, so Im also thinking of a bycycle-discbrake. My be it can go under the cover where the engine is placed?But I will try some electrical thing first. ?
 
Have you pursued a mechanical brake any further? I like the bicycle brake on the motor idea.
I need to do something like this also.
R
 
I used the caliber from an old snowmobile on a disk sander I built. The rotor I believe was from the rear of a GM pickup, turned down to smooth out the wear. These are a good heavy break, stops the 16 inch disk in a second or two where it will coast for 4 or 5 minutes. A bicycle one would work but the pads may wear fairly quick, they aren't meant to stand much abuse.
IMGP0476.jpg

Greg

IMGP0476.jpg
 
That's a really nice sander! The snowmobile brake is a great idea. They make similar ones for go karts- cheap.
I have seen some large industrial lathes stop within less than one second when turned off. How is that typically done? Is it a brake setup on the spindle? Motor brake? Whay wouldn't all lathes come with a motor brake? Seems like and inexpensive upgrade.
R
 
rwm said:
That's a really nice sander! The snowmobile brake is a great idea. They make similar ones for go karts- cheap.
I have seen some large industrial lathes stop within less than one second when turned off. How is that typically done? Is it a brake setup on the spindle? Motor brake? Whay wouldn't all lathes come with a motor brake? Seems like and inexpensive upgrade.
R
Click to expand...

Thanks, built that sander a few years ago for the cabinet shop. will remove a lot of material in a hurry if you push it.
I haven't been around a lot of lathes but over the years I've owned 4, all had brakes. The Taiwanese 14x 40 had a pedal controlled brake that shut off the motor and operated a band brake on the motor shaft, it would stop almost instantly, great for threading up to a shoulder. The Colchester Student had a drum brake on the input to the headstock. The 16x 80 Summit lathe I have now is clutch driven with a wet band brake that comes on when the cutch is disengaged. At slow speeds it stops pretty quick, but takes two or three seconds to stop the 12 inch three jaw if your at 1000 or more rpm. My Hardinge has an electrically operated cork pad brake that rubs on a drum on the motor shaft. it slows it down pretty quick but not instantly, but it coasts for a long time if you shut the brake off.

Greg
 
My Harrison M300 lathe has a primary v belt drive from the motor. The brake is a matching v-shaped shoe pivoted to rub in one of the pulley grooves. The shoe is connected to a foot pedal bar with a lever-based design connected to the shoe by a push rod. An adjustable trip bar interrupts the electrical latch when braking.

I have not powered my lathe yet but I have heard that this is a very effective brake.
 
You must log in or register to reply here.
Back
Top