Anyone have a schematic for an old Sharp 1660C lathe?

[Fear]

I've been checking continuity on wires all day. I'm starting to think it is either in the contactors or the transformer but I'm not getting any action out of anything.
I can't figure out what the "A(R.C)"-pot hanging off of one of the main contactors is for.
Also, should I just be reading 24V AC at X3 and X1 on the transformer?

I'm good at automotive electrical, adequate at single-phase residential electrical and trying to learn 3-phase without involving an ambulance or a hearse.

[reggie_obe]

Do you read 220VAC at the input of the transformer? Terminals: H1 to H3? Do you read 24VAC at it's output, between .X3 and X1? Is the transformer protected by a fuse? If you have the presence of coil voltage (24VAC), does pushing For. or Rev. make the contactor clunk or snap in?

Sharp website has a downloadable manual, but no schematic IF you email listing model and serial# maybe they could dig one up.

[The Metal Butcher]

Looks like an adjustable heater.

[Fear]

Do you read 220VAC at the input of the transformer? Terminals: H1 to H3? Do you read 24VAC at it's output, between .X3 and X1? Is the transformer protected by a fuse? If you have the presence of coil voltage (24VAC), does pushing For. or Rev. make the contactor clunk or snap in?

Sharp website has a downloadable manual, but no schematic IF you email listing model and serial# maybe they could dig one up.

I've already talked to Sharp. They sent me a PDF of the owners manual and parts manual but half the pages are missing and it's almost useless. I asked them to send a schematic and they gave me some little back page minor circuit and nothing more.

Terminals H1-H2 I got 242V and X3-X1 I got 26.5V.

I'm getting the 26V at the power switch on the front.

I'm figuring I should at least hear contactors clicking with directional changes, etc. even with no activity from the motor, but nothing.

The main pair of contactors that supply the motor won't activate. they are powered by circuits 9,10,11&12 but none of those are circuits that leave the panel. They must all terminate at the other two contactors but the back wires to the contactors are hard to read. I can only find two of them at the contactors.

[reggie_obe]

They sent this manual: https://3hytkr1l37jl3m61e5w2fznf-wpe...rts-manual.pdf
Appears to be for several lathes and has no schematic.
Fr the coil to energize, 24V must reach the coil. Are the wires all numbered? You may have your work ahead of you with a 24v test lamp to trace the wiring out. I'd try and test with only the stepdown/control transformer energized to avoid any surprises.

[The Metal Butcher]

You should have a master contactor that gets power from the E-stop. Everything ok there?

[oxford]

Is this tripped?

[nc5a]

It appears the wires have numbers so if they are all intact you should be able to track down the problem using basic troubleshooting skills. First, the nominal 24 vac at X1 & X3 is control voltage and that control voltage should be at either the forward or reverse contactor coil when the button/switch is operated. If 24 vac is there but the coil doesn't pull the contactor in check for an open coil.
Some rules to follow when working on machines that have power to them. Keep fingers, hair and clothing out of the way. block safety switches like door switches so it is in operating mode. Release emergency stop switches so they aren't calling for an all-stop trip. There is more but but I have to go now.

[MaxHeadRoom]

The units below the contactor are O/L's and generally are wired in series with the contactor coil, if an O/L occurs the coil cannot engage until reset is pushed.

[JRouche]

Is this tripped?

Only can an Oxford find a blow fuse. I like it. JR

[Doozer]

It appears the wires have numbers so if they are all intact you should be able to track down the problem using basic troubleshooting skills. .

90% of all lathes with a control panel are the same.
FWD and REV contactors and maybe a main and a control xformer.
A manual is not going to help.
You need basic electrical theory.

I love when guys are asking for a manual for a drill press.
They are so mechanically simple, what possibly could a
manual tell you about something with 4 bearings and 2 pulleys ? ? ? ?


-D

[deltap]

Start at the control transformer and trace the control wires. Starting with a numbered wire it will be numbered the same on the other end. Start a ladder diagram on a sheet of paper and as you locate each wire draw it in on the diagram. This then is a logic map that tells you how the machine works. Diagrams read left to right and top to bottom. A lathe will usually have only a few lines. All the safeties will be in series and you can put a voltage probe on one side of the transformer and with the other probe go right down the line until you find the point of no voltage. You should learn how all the individual devices work and how to test them. A contactor should have coil voltage and close when energized. It should have correct voltage on all 3 legs in and out. Check all wiring terminals for tightness. Check all fuses and overloads for continuity. Look online for a typical wiring diagram and follow it to gain understanding. Look at lots of them to see their differences. Soon you will be an expert.

[Mr Fixit]

Here is a PDF file of a Sharp 1660 that I found with quick google search. Maybe this will be of some help. Google can be a help sometimes. 😂

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://standardmodernlathes.com/docs/manuals/standard-modern-1660-manual.pdf


TX
Mr fixit for the family
Chris

[wmgeorge]

Look for a fuse blown, limit switch tripped or an over load tripped before you tear it all apart. Was it working and just stopped or was not running when you purchased? Stops and limits are in series, Starts in parallel. Is there a cover off or open?

[Doozer]

When you manually close the contactors does it run?
That will give you an idea to look into the main circuit
or control circuits.

-D