Member postings for Robin

When you go beyond cheap it is like pwm but the ON phase is determined by the current, the OFF phase is determined by cleverness. You want to measure the generated Volts to get the speed but the moment you cut the supply, inductance starts flowing big current through the coils via the protection diode which confuses everything. The controller has to make a guess and that is the expensive bit.

I have answered this many times, I find it best to start uncomplicated and then progress.

I'm betting Ron has a wicked idea for a killer, arena robot and has bought a bunch of Amp-Flow, rare earth motors to play with.

Volts times Amps equals Watts

746 Watts = 1 horse power

So 18V x 100A = 1800W = 2.4hp

A 100A controller can handle 100A before it starts to go wrong. It doesn't insist on 100A flowing through the motor.

Protection by limiting current is usually achieved with a fuse.

Limiting the current will limit the torque. Is that what you want?

Russell you have just volunteered to take over. Well done that man

DC electric motors act as generators. The speed increases until the generated Voltage is the same as the applied Voltage.

Starting current is usually enormous.

Once up to speed, power consumption is down to load and making it hot.

Cheap motor controllers depend on turning it on/off many times a second and varying the on/off ratio.

That introduces an interesting 4th factor to the equasion, Inductance. This is the thing that blows up your electronics.

If you want 18 Volts, why not use three 6 Volt batteries?

There is a wonderful thing called Ohm's Law

Amps = Volts / Resistance

The three are inter-related. The current (Amps) flowing through your motor (Resistance) is determined by the power supply (Volts).

To get a meaningful answer, what are you trying to achieve?

That's the self same advertisement that caught me out...

Product images are for illustrative purposes only
Brand may vary unless specified in Name/Description

That Fenner thing was interesting, I din't know you could get Taperlock hubs, wonder if I could convert one of them to a grinding wheel holder? I might even be able to balance the blooming thing...

Have you actually spun up a Taperlock pulley? Andrew Tinsley said they are neither accurate nor repeatable which is not encouraging.

The other pulley in the pair connects to a hardened and ground shaft with no trace of key, Woodruff or otherwise.

It's a grinder so load is minimal but accurate and repeatable are more than a bit desireable, Obviously I need minimal vibration, which is why I am fighting to fit this dinky 1/3 hp cap run motor.

Hi Ian

Everything is available at a price but I could easily start to haemmorhage cash on this, and that is not a word I would usually attempt without a spell checker.

Here's an idea. I make a false nose for the motor shaft to extend it at a larger diameter and then Taperlock the pulley to that.

The new plan means buying an 11mm reamer and a 4mm broach but I can then change the pulley to fit the desgn rather than change the design to fit the pulley.

I need to get back in control of the design. Right now it is all drawing and shopping, I want to do some measuring and cutting.

Robin

A bit expensive if I have to cut the keyway myself, and on a slow boat from China to boot.

Okay, not a Woodruff , an M4 whadda-ya-ma-call-it key.

Is there no end to my humiliation?

Robin is always confused. If the 63 has an 11mm shaft it is probably a 63.

Henry at Bearing Shop has just patiently explained to me that the problem is the smaller sized pulleys where there is not enough meat between the groove base and the taper lock bushing.

The shaft would have to be 37mm long to reach out through the pulley and then through the taper lock. They cannot overlap. I only have 23mm.

Apparently the first Z pulley that does not suffer with this is the 67mm and as Henry has no problem refunding my silly mistake I can shop with confidence.

Still not totally clear on what i have bought. I like the automotive belts, with the cross cut inside edge to help it bend. Unfortunately they give outside diameter, 595mm, the inside diameter, 544mm, but no PCD so it's a pig in a poke.

I cannot find a pulley to fit a frame 56 motor and I am starting to think the world hates me.

The spindle is 11mm diameter by 23mm long with a 4mm Woodruff.

I tried a 50mm taper lock but the screws are on the wrong end.

Surely to God I cannot be the only person on planet Earth who wants to do this

I bought one of those in 3mm to connect a pulley I was making to the motor shaft.

Being a complete broach beginner, I soon hit a snag...

The spec said it could do a slot 30mm long, but the support collar and shim were considerably shorter than that.

Due to the terrible forces involved, overhanging the support seemed like a terrible idea. So I stopped.

Am I wrong?

My goodness, this is a different world to the one I am used to. In this world I know people with 30mm reamers and there is a possibility of a loaner.

If the Bloxwich reamer hasn't survived it's journey through history I might just take you up on that offer Brian. A week would be plenty, it is 12 holes through 1" of T6 aluminium alloy for my great surface grinder project.

Norman Clegg came to me in a dream and told me to bolt 2 SCS30LUU bearings to either side of a 15mm aluminium plate and call it an XY table. I had my doubts but I don't get many celebrity dreams so I decided to give it a go.

Edited By Robin on 03/08/2018 09:37:37

WW2 Harley parts in the original packing grease? NEAT!

I love shopping.