Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: vz58 on September 21, 2012, 08:36:11 AM
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I have decided to convert my Logan Lathe. What I cant seem to find is whether I need a normally closed or a normally open sensor to detect revolutions of the spindle. A youtube video showed a normally closed but the project was never completed.
Any suggestions on a particular sensor??
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I've used several of the C-3 Index kits from CNC4PC.
They work very well 4 me.
Russ
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I used to use the Optek OPB 916B or 917B with good results, just needed a current limiting resistor in line with the LED, I used 220 ohm as it was being fed by 5v.
Hood
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Let me throw out there this is mach3, gecko540,
Does that change anything?
The stepper I can use is only 381 oz in torque. I was planning on running a belt drive with a 2:1 to boost torque and drop velocity, does this sound ok?
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I presume you are meaning you wll be using a stepper for a spindle motor, not the best idea if that is what you mean. Steppers torque drops off rapidly when speed increases until you have almost no torque. Would probably be better to just keep the original spindle motor if you could.
Hood
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Sorry Hood for not being clear. I plan on keeping the 5 hp spindle motor. The stepper is to drive the x axis, the carriage.
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Ah ok thats a relief ;D
Not sure what size the logan is but you should be ok on the X with that motor, Z maybe not but suppose it just depends on the size of the lathe and how hard you are wanting to push things.
Hood
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I have a C-3 index board and it functions well with a slotted disc.
I used a Halls Affect on my lathe and it is excellent, both in preformance and provided for much easier installation on my small Atlas lathe ( no slotted disc required and uses a very small magnet).
I will note that I had two Hall's for free available and they are somewhat costly.
RICH
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Its a 12x40 something.
I plan on either direct drive or 2:1 x axis
For the z ill go 4:1 with another identical stepper.
i've been looking at the sensor you suggested.
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Do you already have the 381 in oz steppers?
RICH
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I have some on the mill, I spoke with keling who told me those were the strongest I could run on the gecko. Do you have a suggestion?
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Hood, I can only find these "OPB 9016B" numbers, do you have a link to buy?
OPB916BZ
OPB916IZ
OPB916BOCZ
OPB916IOCZ
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I have some on the mill
Then you are meaning that you already have the steppers.
Think the drives are good to 3.5 amps and with that thought in mind i was going to say have a look at
Kelling KL23H2100-30-4BM 500 in oz 3A
RICH
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yep he said they were good to 3.5 amp.
When I asked him what was the most powerful he had for the gecko he told me to get this one NEMA23 570 oz/in 3.5A 1/4” Dual Shaft Stepper Motor (KL23H2100-35-4BM)
so 570 oz in
the ones I have on the mill are the just under 400 oz in, the x feed is direct drive and can skip. The y did too until I put 2:1 pulleys on it.
That is why I was really looking for more power on the lathe.
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It is the OPB916B I used, I seem to remember someone saying they stopped producing the 916B and replaced it with the BZ but can be 100% sure.
Hood
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Some of the listed motors have a motor curve and one should look at them and compare how they are rated.
My take on it all is that you want power delivered to the axis which is speed x torque along with a satisfactory axis velocity and acceleration. So this all gets complex quickly and one needs to evaluate.
So looking at the motor curves at some set of defined conditions provides a comparison. For a few bucks you may be able
to dramaticaly change operating conditions ie; say 500 vrs 380 in oz and you get an additional 32% bump in torque with the motor
rpm not far from each other and that allows increased overall capability of the lathe ( 5hp spindle motor with more capable axis).
So you asked and he said here is the largest in oz motor in that frame size. But application of that motor may not be better.
I can't write a book here but just want to shed some light on the matter. If your confused, that's alright....not my intent....
lets just say awareness has been provided.
RICH
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Thanks all.
Still trying to get up with a sensor. Tried ordering but on two different sites it was out of stock or discontinued. There are a ton of sensors on ebay. May have to muddle through them
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Hi.
After 2 weeks of working on it, I got the C3 + G540 + Mach3 Working.
If you need help?
Sincerely,
phillip~