Thread: power feed on mill/drill

Originally Posted by morrisman

That is useful info. Would a friction clutch be OK ? The Harrison lathe uses a spring loaded friction clutch with bronze faces . For the power fed on the mill, you could make up a spring loaded cam device that engages the clutch .

To drive higher loads without going bigger, you can make a tapered clutch, not sure on the best angle but if you are interested i can measure Blondies feed clutch. Too shallow and it won't disengage, too steep and there will be little advantage.

Originally Posted by morrisman

Hi John

If I was going to use a stepper motor, I might as well go all the way and go CNC . But It is worth investigating , thanks

Stuart . I think a Ride on mower or quad bike 12V starter motor would last for a long time , these are aperm. magnet type motor I would think ? In a mill power feed situation, the load on those type of motor would be rather small compared to turning over a internal combustion engine .

12v STARTER MOTOR 110cc Chinese Quad, Pit dirt bike Buggy 50cc - 125cc Thumpstar | eBay


The drawback is, you have to make a reduction gear , and some type of clutch to disengage it eg for manual hand wheel feeding . Not sure about PWM and your comments - but some PWM controllers have a reverse function so that is a handy way to reverse . I haven't noticed any change in speed with load when using the wiper motor , the PWM does a good job in that regard. Mike

I doubt these motors would be designed for continous operation and may overheat and burnout.

Dean

Originally Posted by Sterob

I made a power feed for mt HM-45 a couple of years ago. I used a 24VDC inline gearmotor. I made dog clutch to engage/disengage the drive, used a speed control and a big arsed 24VDC power supply to drive it. Work well. I started a post on here as I built it. I can try and find it if you like.
I considered, steppers, high voltage DC's and settled on the 24V route.
You will need a motor thats has a max speed of about 250 rpm ( for high speed traverse ) with normal speed range of 0 to 200 rpm. Can't remember what sort of power or torque is needed. If you find the specs of a comercial power feed, that will give you clues.
Steve

I would be interested to see this post. It sounds like the way I want to go. This could be one of the first projects on my mill.

Dean

My research at Oatley Electronics so far has revealed
24v 250W geared motor $109
500W speed controller $49

I could not see a suitable power supply on the site.

The total cost seems to be looking at more than I want to pay and I honestly think that it needs to be well under half the cost of a bought unit or it is just an exercise in making something. I have more than enough to do without adding to the list. I am happy to make things that save me a heap of dough but at some point I realize that it is better to just buy it. That is why I bought a new mill after watching for a secondhand one for ages. I am a shinflint but am becoming less so as I get older. Maybe because I want to use my equipment before it is too late.

Anyway has anybody got any suggestions regarding the power supply which I believe is usually the most expensive part, hence my comment on total cost. Not being much of an expert on this matter others will have a better idea on what I need and for less cost.

Comments regarding the motor and controller are also welcome.

I recall something about using components from a treadmill for this type of use. I have seen these in a salvage yard at times. The salvage yard is over an hour away tho so a bit hard to keep checking.

Dean

Hi Dean,

I agree about time, cost and work versus just buying a commercially available one. In terms of a suitable power supply, I would consider looking at a switched mode supply. I think you can get reasonable priced units on ebay that are rated to 3 - 4 amps. Also, it may interest you to know that I have in use a 36 100W DC motor from oatelelyelectronics. I use it to run the oil pump for my one shot system on my mill. I used an old printer power supply, it's only 24V but it still runs the motor very well. In fact I can't stop the motor by hand when it runs. I think the motor cost me $16 a while back and the power supply was going to be thrown out. I small PWM controller would be pretty cheap too.

Cheers

Simon

I am thinking about a belt drive system. When you realize that industrial sewing machines use belt drive and they have quite some large amount of torque at the needle .

I could make a belt detensioner for when you want to free wheel for manual hand wheel use . A simple third pulley that tensions the belt between the motor pulley and the lead screw pulley would suffice ?

And machining custom pullies is so much easier than making gears ... Mike

Originally Posted by simonl

Hi Dean,

I agree about time, cost and work versus just buying a commercially available one. In terms of a suitable power supply, I would consider looking at a switched mode supply. I think you can get reasonable priced units on ebay that are rated to 3 - 4 amps. Also, it may interest you to know that I have in use a 36 100W DC motor from oatelelyelectronics. I use it to run the oil pump for my one shot system on my mill. I used an old printer power supply, it's only 24V but it still runs the motor very well. In fact I can't stop the motor by hand when it runs. I think the motor cost me $16 a while back and the power supply was going to be thrown out. I small PWM controller would be pretty cheap too.

Cheers

Simon

The motor I linked to is rated at 250w. It would need a supply of at least 10A. Another option would be 24v worth of batteries (SLA) and a trickle charger left running. I will check EBay tho.

Dean

A computer PSU will give you plenty of go, but only at 12v. I have a 280w one in my hand right now that will give 16A. Scrounge some old pc's for a 500W plus supply and you should get 25A plus.

Edit, a new 500w PSU online will cost you $50 and give you 34A....

I think you guys are thinking of too much power eg 500 watts = 2/3 HP . At a guess you would only need 1/10 th of a HP to move the table on a 45 series mill/drill ? Mike

Originally Posted by Ueee

A computer PSU will give you plenty of go, but only at 12v. I have a 280w one in my hand right now that will give 16A. Scrounge some old pc's for a 500W plus supply and you should get 25A plus.

Edit, a new 500w PSU online will cost you $50 and give you 34A....

Thanks for the heads up. I was thinking along those lines myself but was advised to go 24v in a previous post to get the added power and less current. Having done some searching of the net since have come to realize that 24v gear such as power supplies are no where near as easy to find. Computer PSU's are pretty good sources of power and very cheap due to them being so common.

I have a planetary geared motor which I remembered after reading of them in a previous post. It is a Johnson 970 series. I have no idea where it came from or what size it is. May be 6v as 12v was noisy and very fast but 6v was normal sounding and a rough guess using a finger against the shaft with flat, 150 rpm. Some searching revealed that they are mostly model motors but the website link I found in and old post at some forum linked to an electrician.

When I get the mill out of its box I will try this motor with a temp connection and see what happens. I should do that tomorrow as it has to come out of the box and will be fine in this weather.

Dean

I don't own a proper mill, but I reckon you'd want a fair bit of grunt to push a steel workpiece against a decent sized cutter.

Re computer PSUs- I have a old one I use as a bench-top power supply. It has a variety of output voltages, but is limited to 4A at 12V. Most of the juice is reserved for the 5V output. The newer supplies might be different tho.

Chris

Originally Posted by morrisman

I think you guys are thinking of too much power eg 500 watts = 2/3 HP . At a guess you would only need 1/10 th of a HP to move the table on a 45 series mill/drill ? Mike

My thoughts on this are mostly based on what I have read on this forum. In Post #14 Sterob suggested specs of around 400w, 24v and 250rpm. I am wide open to other suggestions. He also suggested that a 12v motor will draw too much current and this would make finding a power supply hard. My research so far has told me that this is not the case. As I said before 24v supplies are not easy to find. I think a large 12v would be much easier. ie PC PSU.

I am going to stick with 12v unless there is a compelling reason to consider otherwise. The motor from Jaycar I first mentioned is rated at 14A full load at 12v. This is 168w or about 1/4 hp. Max speed is 160rpm. A controller such as 12 / 24VDC 20A Motor Speed Controller Kit which I hope is the right type. It uses adjustable pulse frequency to reduce motor noise. It is $40 in kit form and needs a housing but this would not matter in this case. Total for the controller and motor is $80. Add $50 for a PSU for a total of $130 plus a few bits such as a pot and some limit switches etc. Much cheaper than the cost of the 24v stuff.

I had around $1000 after buying my mill and table saw to buy stuff for the mill. I is shrinking steadily although a lot of what has been spent will be replaced. I need to decide how to apportion this money to buy everything I am going to need because I don't often get the chance at this sort of cash. The mill was paid for out of my tax return. I also need to buy anything else I need for the lathe.

Chris what size PSU have you got? They are available in quite large capacities. (I just checked EBay) ie 980w for $68 including postage from Melbourne. The rated 12v capacity is 45A. That would easily cover the requirements. I just picked a big one to ensure it would be capable. Obviously a smaller one would be quite suitable.

Dean

Originally Posted by Oldneweng

I doubt these motors would be designed for continous operation and may overheat and burnout.

Dean

I also think I discounted using a stepper motor as I didn't think I could get the speed range. ( Not sure...it was a fair while ago....)

Originally Posted by Oldneweng

I would be interested to see this post. It sounds like the way I want to go. This could be one of the first projects on my mill.

Dean

https://www.woodworkforums.com/f65/ho...hm-45-a-39480/

Post 15 is the final design.
The thread is a little disjointed, as I was trying things and then changing things,,,,
My motor is 250W ( I was some ways off the estimate.... )

I tried a gear train ( with 4:1 reduction ) but the noise was huge so I then changed it to a direct drive wit a dog clutch.