Thread: Wow - huge price difference

You call that grubby! I've just noticed i was running the lathe with no oil in the front oiler......oops.......
Chris, I'm hoping looking at the wave produced the tacho will have no problems reading the signal.

I was thinking : is it worthwhile having a permanent tacho on a lathe that has fixed speeds ? I measured the 16 speeds on the Sheraton and made up a chart , the chart is stuck on the wall behind the lathe . I can see why a tacho would be handy on a variable speed lathe, but not so on a fixed speed setup ..Mike

Looking good Rob. Don't worry about the dirty lathe, it's a sign that it gets used and besides, you're not the only one with grubby machines. Especially when in the middle of a project....

Hey! I got my Tacho yesterday too! Looks OK. BTW, on your lathe it looks like you have by-passed the gearbox, is this the case?
Can only imagine how quieter it must sound without the gear noise!


Simon

Originally Posted by simonl

Looking good Rob. Don't worry about the dirty lathe, it's a sign that it gets used and besides, you're not the only one with grubby machines. Especially when in the middle of a project....


Simon

Note that at least my gears are clean.

My lathe is belt drive Simon, so nothing to bypass.

Been working on the DC motor cooling system today and nearly finished. Two fans with a separator to prevent cavitation.

Check this out - awesome.

Rob

Originally Posted by morrisman

I was thinking : is it worthwhile having a permanent tacho on a lathe that has fixed speeds ?

Mike,
I think so. I can never remember what speed I last set on my Hercus. The tacho is a lazy man's way of checking the belt settings. And I intend adding a VSD later.
Chris

Ewan,
that signal looks good.

Hi Mike,

I'm only adding a tacho because I'm going down the variable speed route - hope it works out.

No point if you have set speeds and a chart as now.

Although it can't do any harm being there

Rob

Well my red tacho finally arrived and it looks impressive.

It lights up and displays a full row of zeros very nicely.

I can also report quite conclusively that the optical sensor is most definitely 5 volt and does not have a current limiting function.

How do I know this ?

Well, smoke comming out of an IC chip is probably a good indication that not all is well.

Yes, I cooked it, well and truly - so moving right along, a Hall sensor is looking considerably more appealing at this stage.

So Ewan, tell us what you've got.

Cheers

Rob

As soon as I have my tacho and get it working I'll let you know.

Originally Posted by nearnexus

Note that at least my gears are clean.

My lathe is belt drive Simon, so nothing to bypass.

Been working on the DC motor cooling system today and nearly finished. Two fans with a separator to prevent cavitation.

Check this out - awesome.

Rob

Hi, what type of power supply and controller are you using to power the motor.

Originally Posted by Auskart

Hi, what type of power supply and controller are you using to power the motor.

I'm using a KB Electronics KBI-240 controller.

This is 240 AC mains in with 180 V DC out (inverter) with trim pot adjustment for max/min speed, acceleration etc.

It uses a 5 K Ohm potentiometer to control speed with a reverse function.

Rob

G'Day Rob,
A 5 volt regulator would have held the magic smoke in. Had an Omron reflective and a Fotek proximity sensor turn up during the week, but no time to play, maybe at the weekend ?,
Regards,
Martin

G'day Martin,

Yes I know, but it's all extra money, and I'm cheap

I would rather buy a Hall sensor that I'm pretty sure will do the job.

Famous last words.

I had nothing to lose with the optical - and it did what I half expected it to. Fizzzzzzzz.

So moving right along, time to try something different.

Nice looking little tacho display though.

It's only ABS plastic so I will have to mount it where runaway hot chips from my tool post grinder and carbide milling exercises can't inflict damage on it.

Reading up on Hall sensors it sounds like most require a south magnetic pole to trigger a response - have you read that ?

Cheers

Rob

Depends on the sensor and which side of the sensor you point at the magnet. I found with the sensors i got one side worked with both N and S and one side worked with one only.

H, where can I source one of these controllers and what is the cost.

Thanks.