115 V DC Motor lathe powerfeed?.

Hello, have an ML7 that needs an independant carriage feed fitting to the leadscrew handwheel end, the problem being, which would be the best motor to use ?. Many years ago, I made a screw cutting gearbox for it from one of the designs in ME, which enables it to cut threads from 7 to 26 tpi, works a treat, but I lost the fine feed facility for the self act, hence the above question.I have 2 motors available, a 12v wiper unit and what looks like a new 115v DC motor ,1/50 hp with a 43 rpm reduction output, but have not a clue how to power it !.It looks the nicer unit, but if I cant power it ,will use the 12v one. Can anyone help please.

Hello Mike, I cant fit a fine feed cluster because there isnt any room for one unfortunately.I wouldnt mind going the stepper motor route, but again, dont know much about them regarding the electronics bit. So perhaps the wiper motor is my best option. Regards, Roger.

Mike, thanks for the info,

Roger.

Hello Roger, good evening.

Please see here **LINK** . It's a simple feeding system for a small milling machine but perhaps it has all you need for your lathe. It's made with a simple and cheap stepper driver **LINK**, a stepper motor bought from ArcEuroTrade **LINK** (ref. 160-010-00400) and some adequate power supply.

I'm just a satisfied customer from the companys referred.

Hope this helps
Dias Costa

Edited By dcosta on 02/09/2013 22:23:12

Hi Roger

What is the mains voltage where you live if it is in the USA then what about a variable speed AC to DC convertor from

http://www.surpluscenter.com/sort.asp?catname=electric&keyword=EPMC

This will give a feed rate from over 5 inches per minute down to 0.022 inches per minute.

Just wire it up and full control with a single knob to control the speed.

The initial setup can be a bit fiddly but once setup properly will give excellent control over the feed rate.

If you are on 230 volt AC main then a stepdown transformer is required to out put 110volts AC.

A DC motor Fanatic

Eric

Edited By oldvelo on 03/09/2013 03:06:48

Hello Dias, the way youve described and Mike as well, seems to be the way to go. Thank you.

Hello Eric, I live in the UK which 240v AC. The DC motor I have is a lovely little unit, made by Bodine of Chicago, unused I think, which would be perfect if I could get a 115DC powersource !. It also has 4 wires coming out of it, which complicates things a bit more. As an aside, the chap I bought it from ( I must have a chat to him in case he knows of a powersource), is 96 years old,and during WW2 , was on the liner Brittanic going to Canada, escorted by the battleship Rodney and 5 destroyers, when the Hood was sunk. Rodney and 4 destroyers buggered off to help sink the Bismark, and left just 1 destroyer as an escort, but they made it to Canada unscathed !. The most interesting ( and lucky) bloke Ive ever had the pleasure of meeting.

Thanks for your interest, Roger.

Roger,

There is some useful info on Bodine 4-wire DC motors, here

... hidden within the usual bickering !!

Could you please give us full details of what's on the rating plate of your motor.

MichaelG.

.

P.S.   Here is a Bodine Catalog, which might help with identification

Edited By Michael Gilligan on 03/09/2013 22:51:02

Edited By Michael Gilligan on 03/09/2013 22:55:09

Hello Mike, looked at the PM page you noted and according to Larry Vanice, mine is a shunt wound unit so will need DC power, if it had been series wound, would have run off AC as well. You are right, some people on the PM site, bloody hell !!!!. I might call in and see the old gentleman I bought the motor off and see he has something to power it. Anyway, motor details,

Type NSH 12RH , No 438ZDO.70, Volts 115, Amps 0 .33, Hz DC, HP 1/50th, RPM 1725,

Duty CONT, FF1, Ins A, Torq 11.7 lbs ins, RPM 43, Ratio 40:1.

Thanks, Roger

Hi Roger,

The simple way is to feed the motor with half wave rectified 240 V mains. This will be equivalent to feeding the motor with 120 V full wave rectified mains. You just need to put a single diode in series with the motor. You could feed the motor/diode from a normal light dimmer to provide variable speed.

High DC voltages are more dangerous than high AC voltages so make sure everything is properly enclosed and earthed.

Personally I prefer to use low voltage motors for this sort of application.

Mike

Roger,

I think 1/50th HP might risk being underpowered for the job; and, as Mike says, low voltage [*] is much safer for this sort of application.

... It's probably best to follow the earlier advice, and use either your 12volt Wiper Unit, or preferably a Stepper Motor.

Save the Bodine unit for some more appropriate project.

MichaelG.

.

[*]

Forgive me if I am stating the obvious but ... Although we use 110volt AC for "safety" power tools; these use an isolating transformer, and a centre tap is taken to Earth, so the exposure risk is only 55volt AC.

By comparison 115volt DC is dangerous [especially if derived the way that Mike mentioned].

Mike C, Mike G , hello, wiper motor it is then for now !. Ill still have a look at stepper motors , they sound

interesting, regards , Roger.

A wiper motor is quite powerful, I use one to power the table on my vertical milling machine. Its an old Lucas with wound fields. I extended the shaft that goes through the worm wheel, and fitted a sproket to fit a bit of bike chain. It's quite happy running on 17 volts, and could possibly go as high as 20 volts, or you might be able to find a 24 volt motor from a truck. Ian S C

Ian, as you say, the wiper motors are quite powerful arent they. Did you make up a control box for it or obtain one off the shelf so to speak ? Roger.

Just for interest, I found a worm drive g/box that might well do for a power feed conversion. It's off a grass cutter, this has a clutch to drive rear wheels. The gear box is worm and wheel, about 8 to 1 and has a neat multi-plate clutch built in. The whole thing is a cast ally box about 3" cube. I think the mower was Aus. made.

Roger, Got the motor at the local dump, and control the speed by a 3 possition switch , switching in resistors made from nichrome wire an old electric heater, and a double pole switch with on off on, giviing foreward and reverse. The power supply is a transformer from an old Xerox copier, it's about 8" sqare, and i'v wound an extra winding on it to isolate it, as the transformer is a auto type, ie., the secondry is connected to the primary. Ian S C

Gordon, thats another possibility, surprising whats out there isnt it.

Ian, bit beyond me Im afraid with resistors and transformers, but thanks anyway. Regards, Roger.