Warco WM16 Powerfeed

[Chris BuxtonParticipant @chrisbuxton55939]

I've just acquired a Warco WM16 milling machine and wanted a X axis power feed for it.

I came across Mikes workshop **LINK** and liked his approach.

I've beefed up the motor/components to cope with the larger mill.

All the components were purchased off fleabay for around £45.

24v 150rpm gearbox motor 35W peak.. Runs at 11W on fast return on my mill.

24V 3A power supply unit

120X120x90mm Waterproof plastic project box

20A PWM Speed controller Module

Couple of switches

The power supply is adjustable slightly via a pot, so I've set it at 28v . The lead screw is a 2mm pitch and with this motor & gearbox gives 35cm/min fast travel. It slows down to absolute crawl yet still has enough torque to cope. The Power supply is screwed to the wall so the cable to the powerfeed is a safe low voltage.

[Chris BuxtonParticipant @chrisbuxton55939]

[David CanhamParticipant @davidcanham77137]

Hi Chris,

I am one post above you also with zero input so i thought i'd say hello. Good luck with your model engineering

David.

[JasonBModerator @jasonb]

Steve, do you know whet the gear ratio is on the gearhead to give the 150rpm at 24V?

[Stuart BridgerParticipant @stuartbridger82290]

Nice project, inspiring. Especially given the cost of original equipment units.

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 10/09/2019 19:58:59:

Steve, do you know whet the gear ratio is on the gearhead to give the 150rpm at 24V?

Jason, If its the motor I think it is (approx 5000 rpm) then 33/1 but dont quote me on that, there are a number of models in this range 12 volt and 24 volt and the spec given is often not that accurate.

[Stuart BridgerParticipant @stuartbridger82290]

Hi Chris, how did you work out how much to "beef up" the original design?
Also having read Mike's article, I did find his rapid/return feed logic a bit difficult to get my ahead around, but i guess it makes sense when you understand it.

[John MCParticipant @johnmc39344]

I've been looking at this design for a power feed for a mill I'm working on. Two reservation, firstly is that there is no means of instantly disengaging the drive to the table. Secondly, electrical stops, how accurate are they? OK for limiting the overall feed. Does the motor stop instantly or is there a finite period of slowing down?

Neither of these are "show stoppers" for me, I'll sort out a lever operated dog clutch. As for reliable/accurate stops I can work around that one, disengage the drive near to where I want to stop the feed and manually feed up to a point on the dial/DRO.

John

[Chris BuxtonParticipant @chrisbuxton55939]

Posted by Stuart Bridger on 11/09/2019 10:57:47:

Hi Chris, how did you work out how much to "beef up" the original design?
Also having read Mike's article, I did find his rapid/return feed logic a bit difficult to get my ahead around, but i guess it makes sense when you understand it.

The amount of extra beef applied was really in the end… determined by best bang for buck. That 150rpm gearbox motor combo is £20 .. after that the price of them quadruples. 24V power supplies are dirt cheap £7, 20A PWM module £4

I figured the more power the better for torque at very low rpm.

I determined the torque of the smaller and slower 60rpm motor/gearbox used originally by Mike, that apparently struggled a little under some circumstances. And then went bigger until my Yorkshire wallet complained.

[Chris BuxtonParticipant @chrisbuxton55939]

Posted by John MC on 11/09/2019 11:54:21:

I've been looking at this design for a power feed for a mill I'm working on. Two reservation, firstly is that there is no means of instantly disengaging the drive to the table. Secondly, electrical stops, how accurate are they? OK for limiting the overall feed. Does the motor stop instantly or is there a finite period of slowing down?

I haven't implemented the stops as of yet. On the website link its stated that stop accuracy is 0.01mm, which would be more than accurate enough for me.

The motor does stop instantly at cutting speeds. I may add a panic stop button in the future if I feel the need.

[not done it yetParticipant @notdoneityet]

I would think there would be a difference in stopping time between feed speeds and fast traversing due to the inertia?

Not the same drive, but the table power feed on my Centec 2B certainly doesn’t stop instantaneously. There is likely a programmable brake on the VFD (if I wanted to use it), but the table does not move far at switch off. The important thing is consistency – like how far it takes to stop at the same feed rate and cut. I would think a mechanical trip would be better – my lathe is very reproducible when using the carriage trip.

Question might be as to whether there is a brake on the motor used in this design.

[TrevorhParticipant @trevorh]

Hi

I have gone the Purchased power feed route and bought one of these from Warco for my WM16

and as expected as its mean't for a WM18 I need to change a few things

I will post as I go

Trevor

[TrevorhParticipant @trevorh]

So with the handle removed the first problem was the shaft size vs the gear bore

not a sliding fit – more a throw on from a long distance so I machined a bush

This at least got the gear fitted nice and true

next keywayed the bush keeping it in the collect

next onto the actual main body but thats for another day

trevor

[mechman48Participant @mechman48]

I have fitted a similar system to my WM16 using a 12v wiper motor free gratis, a 240/110v to 12v dc transformer eBay, approx £12, a PWM with on/off switch, eBay again, approx. £5, 2 pieces of 10 mm aluminium plate free gratis, some bit's n' bobs from scrapbinium box, universal joint from defunct socket set, stainless steel sheet from skip diving, 'e voila' a working 'X' drive. It doesn't have fast forward/reverse ( yet ) but on full PWM speed it copes very well, can't remember what mm/min it does at the mo'.

George.

[TrevorhParticipant @trevorh]

Hi George, very nice, honestly yours would have been beyond my abilities, so this is what I ended up with

just had to add a stand off plate to get the drive gear in the right position as shown below

and we were good to go

Not sure that I am going to fit the auto return end stops and switching gear tho' 1. takes up quite a lot of room 2. I will always be there operating it so the chances of it traversing that far is quite slim

Trevor

[mechman48Participant @mechman48]

Looks the biz' Trev, nicely done.

George.

[John MCParticipant @johnmc39344]

Posted by Chris Buxton on 11/09/2019 18:17:23:

Posted by John MC on 11/09/2019 11:54:21:

I've been looking at this design for a power feed for a mill I'm working on. Two reservation, firstly is that there is no means of instantly disengaging the drive to the table. Secondly, electrical stops, how accurate are they? OK for limiting the overall feed. Does the motor stop instantly or is there a finite period of slowing down?

I haven't implemented the stops as of yet. On the website link its stated that stop accuracy is 0.01mm, which would be more than accurate enough for me.

The motor does stop instantly at cutting speeds. I may add a panic stop button in the future if I feel the need.

Thinking some more over the question of stops. I believe that electrical switches that limit the overall length of feed are important. I would suggest that a quite considerable the torque is applied to the lead screw. If it was not disengaged before the limit of travel is reached then some damage will be done. Something may "give" in the motor/gearbox, worse still damage to the lead screw and nut. Even worse still the work table on these very lightweight machines could be twisted.

With no limit switches it would only take a momentary distraction , then the damage is done!

John

[TrevorhParticipant @trevorh]

Hi John

That is a valid point and under normal circumstances I would fit said switches but

1. I have the extended bed length and together with the max speed feed rate it takes several seconds to traverse one end to the next

2 the lost room taken up by the location of the reversing switch is quite excessive when taking into account I only work on small projects

Even on rapid traverse it still takes approx 15 seconds to travel full distance

So for me its just not worth the hassel vs the rewards by paying attention to what I am doing

trevor

[Chris BuxtonParticipant @chrisbuxton55939]

I've found that I have a "natural" limit switch in my design and so the limit switches for end of travel are not so important. I found this out due to a plastic box getting underneath the rotating hand wheel whilst under power. The power from the motor under high torque conditions overwhelmed the speed controller or 3A power supply causing it to shutdown in a kind of PWM mode. …. Handy that .

Edited By Chris Buxton on 30/10/2019 12:07:46

[mechman48Participant @mechman48]

Blew the fuse then Chris .

George.

[Chris BuxtonParticipant @chrisbuxton55939]

Posted by mechman48 on 30/10/2019 17:57:57:

Blew the fuse then Chris .

George.

No, just been experimenting with it. Its the power supply which cuts in and out… It must have some over current detection. Its a great safety feature

[mechman48Participant @mechman48]

Thanks Chris, didn't know that, I have a PWM fitted to my set up so it's something to bear in mind.

George.

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