Help with a Small lathe

[Nev WhitehurstParticipant @nevwhitehurst53938]

Hi all , I have recently brought a small lathe it needs a good clean up as it has surface rust and the motor has burned out . I was just wondering if anyone on here knows what lathe it is as there are no numbers or name on it . I recently sold my uncles lathe and sore this at a fair price so I think I paid £80 for it and it has a good selection of collets a 3 jaw chuck and other bits and pieces which as they stand are in a sorry state but I am working on it cleaning it up . I have been given a jack jk 513a motor with control box and I want to put a speed control switch on it but have no idea how to go about attaching one as you can adjust the speed via the control box but I don’t have a pedal for it . If anyone on here can help me out I would appreciate it thank you

[John HaineParticipant @johnhaine32865]

Looks like a nice watchmakers pattern lathe and great to have a collet selection with it.

Regarding the Jack motor, a few people here have fitted them to small lathes successfully and got round the foot pedal problem.  Some searching on the forum should help and hopefully one of them will also provide some help.

[Nev WhitehurstParticipant @nevwhitehurst53938]

Thank you John

[noel shelleyParticipant @noelshelley55608]

As John has said It looks like a watchmakers lathe handy for small work. The collets will make it useful. I don’t know the motor but others here will be able to help. Welcome to the forum and best wishes for the new year.  Noel.

[Nev WhitehurstParticipant @nevwhitehurst53938]

Thank you Noel . Wishing you a great new year

[bernard towersParticipant @bernardtowers37738]

Some Manufacturers used to stamp their name on the end of the bed and as yours is covered in paint!

[Nev WhitehurstParticipant @nevwhitehurst53938]

<p style=”text-align: left;”>Hi Bernard . I am in the process of cleaning it up . I have now removed all the paint and rust and there are no names or numbers stamped on it anywhere . I am going to repaint it as there is hardly any chrome plating left on it just black cast should have it finished over the weekend then I’ve got to sort the motor out</p>
 

[Martin of WickParticipant @martinofwick]

Q1 What is wrong with the motor attached to the lathe and why do you need a foot controller? Try rewiring and using that motor first, it may be all you need.

Q2  By a ‘Jack’ motor, Do you mean an electronically controlled BLDC motor of the type now commonly used for commercial sewing machines?

If the answer to Q2 is yes, then there are a number of options available. Depending on how your unit is configured, you may be able to leave everything associated with the hall speed sensor intact and use a simple mechanical linkage solution. This may be preferable if you want foot control as these motors usually come with parts to permit this (foot or knee levers being normally used for sewing machines).

Alternatively, you can replace the hall sensor with a voltage divider and potentiometer but this will require some simple ability for circuit design and construction. There are H&S risks involved with this approach but they are manageable. This would be more suitable if you want a more precise and stable speed control, as with an engineering type lathe.

To get some idea, trawl around on the net or you tube and get a feel for what others have done.

 

 

[Nev WhitehurstParticipant @nevwhitehurst53938]

hi Martin . I don’t want a foot control , I want to use a speed control switch instead of a foot control . The motor that it came with is burned out I had a friend look at it and it’s no good . I’ve been given the jack jk 513a motor and control box which does work but I want to fit a speed control switch to it but not sure how to go about it

[Martin of WickParticipant @martinofwick]

OK, then 513 comes with a Hall effect speed controller. It will be the small box with the silver lever sticking out. That lever moves the magnet above the Hall sensor, driving the speed control electronics. The lever has a strong return spring that you can remove. This will enable the lever to be moved to a suitable position(speed) by hand and left there without immediately reverting to the off position when released.

I suggest you set up the BLDC motor on the bench and investigate that method of control and see if it is adequate for your requirement. If you are content with a mechanical approach you may consider modifying that lever system or implement some mechanical resistance method for more precise control. This would help to avoid inadvertent control changes, as the range of movement from min to max speed is quite small with the Hall sensor.

[Nev WhitehurstParticipant @nevwhitehurst53938]

Hi Martin . I have the control box and the little square box with the lever and all is working as it should . I am not 100% sure what I want to do will work as it has a built in speed control as you can program it to as fast you want it to go or as slow as you want it to go I understand all of that side of it I just want to know if it is possible to replace the small square box with a speed control switch which you can change the speed by turning the button like when you pull the lever it starts the motor to which ever speed you want . I have made a lever up which I can run it on 3 different speeds and it will stay on that speed intill I change it  . All in all all I want to know can I fit a speed control switch instead of doing the above or like what you said about removing the spring

[Martin of WickParticipant @martinofwick]

On the main control box, you can only set the minimum and maximum speeds ie the speed range over which the speed control will operate, for example, minimum 500 rpm, maximum 2000 rpm or 2000 rpm to 3000 rpm etc. You can also set direction of rotation.

The simple answer to replacing the speed control box is no.

The long answer is yes, if you are competent with electronics and are prepared to modify the speed controller within the speed control box. You will need to determine from the speed controller what signal voltages define the motor start and and maximum speed of the motor. Knowing that you can replace the Hall transducer with a potentiometer.

Say for example these voltages were between 2.2v for motor off and 4.8v for motor max, then you will need to construct a voltage divider with potentiometer, or a two divider voltage clamp with potentiometer to replace the Hall switch.

You will need to make sure your ‘low voltage’ circuitry is well isolated from anything you may touch and anything metallic as it will be at high potential  with respect to ground (ie possibly mains voltage or greater). I suggest you do not go delving around in the main control box unless you are comfortable working with high voltages.

[Nev WhitehurstParticipant @nevwhitehurst53938]

Hi Martin . I have decided to leave it as it is and just use the lever I made u for it . I am normally confident with electrics but not knowing how to do what I want to do I’ve decided to leave it alone , plus the power it holds for at least 2 minutes after it turns off is of some concern so it’s better to be safe than sorry . Thanks for your advise

[old martParticipant @oldmart]

Thats the size of lathe that would work well with a sewing machine motor and foot operated speed control. As for cleaning it up, I would recommend taking great care with removing the rust, wire wool and oil will remove the rust without damaging any existing metal. Do not be tempted to remove the rust pitting, but think of it as being a way of holding the lubricant used on the parts. If you can carefully dismantle and clean all the parts all the better.

[Nev WhitehurstParticipant @nevwhitehurst53938]

Hi old mart . I have cleaned it up using oil and wire wool , it would have been chrome plated but there are only a few small patches of it left , I have stripped it all the way down including the cross slide giving it a new coat of paint as it needs something on it as it is mainly the cast showing . I will put some pictures up once I’ve finished it , it has turned out better than I expected now I want to get it finished and then have a play with it . Hopefully I will have it finished over the weekend as I’m taking my time with it and not rushing to get it done . Thank you for your advice old mart

[old martParticipant @oldmart]

The foot operated speed control that is used with sewing machine motiors could be replaced with a standard rotary one for mounting higher up. You would have to check the power rating and total ohms first.

The lathe will be very good for small jobs and you should keep us updated with the restoration.

[Nev WhitehurstParticipant @nevwhitehurst53938]

Thanks for that Old Mart . Weather stopped play today . Hoping to get it finished soon and I will post some pictures on once I’ve finished it . Not much left to do now but with this weather I haven’t been out as I’ve got arthritis and 3 bulging discs in my back and this weather is knocking me for 6 , but as soon as I feel up to it I will get back down the shed to finish it off unless I can get round the wife and bring it into the house to finish it off but I can’t really see that happening right now lol . Thanks again Old Mart

[Nev WhitehurstParticipant @nevwhitehurst53938]

Hi all sorry it took so long to get back with the finished project but here it is still got a couple of things to finish off but it’s all working I had a little play with it and all seems well , I was given another motor and control box which seems to be easier to use than the jack one this one is a redsun which is a lot quieter than the jack

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