Thread: Mill Power Feed Clutch

Originally Posted by Anorak Bob

And Phil, any chance of a beginner's primer on PTO clutches. I'm a city boy.

BT

Originally Posted by Oldneweng

I actually started this thread just to find out what materials to make the clutch disks out of but have not had any results yet.

Dean

Hi Dean and Bob,
I've been out all weekend and only had the phone and aint it a bugga to type with those things
John (rascal) has linked to the exact clutch plates I used. The Bareco plates come in different sizes as you will see from the link.
On a tractor PTO, the shaft joins the PTO spline on the back of the tractor to the implement input shaft. The clutch plates are clamped between steel plates using long bolts on springs that are used to apply driving pressure.
On the camelback I had an existing drive clutch that could be engaged and disengaged so I adapted the Bareco plates to suit my application.
If I find the pics I will post them.
Bare Co - P.T.O: Clutch Discs


Phil

i remebr using masonite discs for clutch plates in pto but them days it was hard to find plates in the tool box now a days id probably even look at one of these Milwaukee 2415-20 M12 12V Cordless 3/8" Right Angle Drill Driver (Bare Tool)

Originally Posted by Steamwhisperer

Hi Dean and Bob,
I've been out all weekend and only had the phone and aint it a bugga to type with those things
John (rascal) has linked to the exact clutch plates I used. The Bareco plates come in different sizes as you will see from the link.
On a tractor PTO, the shaft joins the PTO spline on the back of the tractor to the implement input shaft. The clutch plates are clamped between steel plates using long bolts on springs that are used to apply driving pressure.
On the camelback I had an existing drive clutch that could be engaged and disengaged so I adapted the Bareco plates to suit my application.
If I find the pics I will post them.
Bare Co - P.T.O: Clutch Discs


Phil

Thanks Phil. I might be looking for these clutches for a different reason lol. I have a tractor recently bought that will probably need a PTO shaft.

Dean

Originally Posted by tanii51

i remebr using masonite discs for clutch plates in pto but them days it was hard to find plates in the tool box now a days id probably even look at one of these Milwaukee 2415-20 M12 12V Cordless 3/8" Right Angle Drill Driver (Bare Tool)

I dont understand how masonite could be used as a clutch plate unless it is glued onto a steel plate. Thinking about that actually gave me an idea. I can experiment with materials. Now I have you to thank for assistance. Thanks for jogging my memory.

Dean

No worries Dean,
Apparantly the original clutch had leather glued to one of the plates.

Phil

the masonite discs were a temp replacement for the discs as in the bare co link but lasted for quite a while used them in post hole digger and slasher clutches but then we didnt have ebay or local agents with stock in the store it was a month wait so it was an improvisation
john

Having always had a manual mill, the idea of an add-on feed drive has been on my 'round tuit' list for years.

The Ueee/Vernier overload clutch concept really merits consideration. I made up something along the same lines years ago to replace a shear pin inconveniently located inside the feed gearbox of a lathe. The overload clutch has been an unqualified success for reliability, ease of adjustment (very important when you want the prototype to be the finished product) and has audible feedback when it slips on overload. That clicking tells you the instant that something is not right. Wear does not seem to be a problem, and it's simple to make, and compact as well.

So I have sketched up a compact feed drive for my Arboga - see attached. It does need a keyway, but not splines.
The disengage clutch is as per the worm/wormwheel system seen in lathe feed drives.

Cheers,
Bill

Feed clutch concept.pdf

Originally Posted by tanii51

the masonite discs were a temp replacement for the discs as in the bare co link but lasted for quite a while used them in post hole digger and slasher clutches but then we didnt have ebay or local agents with stock in the store it was a month wait so it was an improvisation
john

Ok I have got it now. I went back and had a proper look at the clutches and found a drawing showing the breakdown of them. I was thinking car clutch where all contact surfaces are attached to one end or the other. Either the motor or gearbox. Even with the twin plate clutches. So are these disks sacrificial?

Dean

Originally Posted by WCD

Having always had a manual mill, the idea of an add-on feed drive has been on my 'round tuit' list for years.

The Ueee/Vernier overload clutch concept really merits consideration. I made up something along the same lines years ago to replace a shear pin inconveniently located inside the feed gearbox of a lathe. The overload clutch has been an unqualified success for reliability, ease of adjustment (very important when you want the prototype to be the finished product) and has audible feedback when it slips on overload. That clicking tells you the instant that something is not right. Wear does not seem to be a problem, and it's simple to make, and compact as well.

So I have sketched up a compact feed drive for my Arboga - see attached. It does need a keyway, but not splines.
The disengage clutch is as per the worm/wormwheel system seen in lathe feed drives.

Cheers,
Bill

Feed clutch concept.pdf

Hi Bill,
I really like that design. The biggest drawback of the verniers is getting the tension on all the balls similar. You are right about the sound it makes, there is no mistaking it. On the vernier it is simply behind a large screw in bung so adjustment is nice and easy.
The more i think of it the more i like the idea of using an old cordless, clutch and all, for the Mar's feed. It will be the controller and programing that will be the hardest part.
Dean, i'm guessing you don't have a tip shop anywhere near you, mine always has piles of old cordless drills, did you want me to pick a couple up and send them your way?
Cheers,
Ew

Originally Posted by Ueee

Hi Bill,
I really like that design. The biggest drawback of the verniers is getting the tension on all the balls similar. You are right about the sound it makes, there is no mistaking it. On the vernier it is simply behind a large screw in bung so adjustment is nice and easy.
The more i think of it the more i like the idea of using an old cordless, clutch and all, for the Mar's feed. It will be the controller and programing that will be the hardest part.
Dean, i'm guessing you don't have a tip shop anywhere near you, mine always has piles of old cordless drills, did you want me to pick a couple up and send them your way?
Cheers,
Ew

No. The tip shops around here have a very limited choice. I think farmers have a different idea of what is good and what is not lol.

Thanks for the offer but I will leave it for now. I have enough stuff to organise already and as I already have all the main components for my power feed I should use them or I might get in trouble or something. I have an old 12volt cordless which is useful for a 12v supply but it does not have a clutch. I have 2 with clutches but both still work and having 2 is useful a lot of times.

Dean

I have started making my power feed. I will try to remember to take some pictures when I have something to look at. I have nearly all of the plans worked out now. I do most of the working out at work as we often have long periods of just monitoring jobs. I have been thinking of digital readouts lately. I cannot afford a full setup so have decided to get individual scales with a 3 axis digital readout.

I want to know how to combine the limit switches and the scales on the mill without either getting in the way of the other. I want to work out the arrangement for limit switches so I wont have to change them to fit the scales later. Pictures showing the arrangements would be useful. I would also like to know if anyone has any idea of cheaply available limit switches. At this stage I am looking at micro switches as the limit switches I have seen are too expensive. May be cheaper to make some. I have heaps of micro switches off stuff I have pulled apart.

Dean

PS Does anyone have any suggestions where I can get scales and readouts. H&F have them but I want to have a good look around.

A quick Google Image search revealed this little gem.

This is the link to where you can find the build of it. http://www.homemodelenginemachinist....er-feed-18441/

Originally Posted by matthew_g

A quick Google Image search revealed this little gem.

This is the link to where you can find the build of it. http://www.homemodelenginemachinist....er-feed-18441/

That is an interesting find considering that I am in the throws of designing with a view to making one.

Originally Posted by Oldneweng

I would also like to know if anyone has any idea of cheaply available limit switches. At this stage I am looking at micro switches as the limit switches I have seen are too expensive.
Dean

PS Does anyone have any suggestions where I can get scales and readouts. H&F have them but I want to have a good look around.

Hi Dean,

Some time back I purchased a couple of these (or similar to) to use as limit switches on my mill head lift/lower. Dirt cheap and they are reasonable quality. Plenty of other types on ebay.

http://www.ebay.com.au/itm/Industria...09d0239&_uhb=1

I also recently installed a DRO on my mill. Just the cheapie igaging type with the remote readouts. Got sick of counting hand wheels and dealing with backlash. Early days, but I have been very happy. Best thing I have done it the mill so far!

I can post a pic if you want but it's just a stock standard install with the scales protected by being enclosed in aluminium C channel.

Here's what I bought:

http://www.ebay.com.au/itm/Igaging-2...f5daa08&_uhb=1


These look OK. These were not available when I was looking.

http://www.ebay.com.au/itm/Igaging-2...9e7b37f&_uhb=1

My only criticism at this stage is there does appear to be a small amount of hysteresis in the readout when changing direction. It could be my imagination but that's what it seems like. I'm not meaning the backlash either. I'm talking hysteresis to the amount of 0.01 - 0.02mm though so it's still more accurate than I could every achieve with my hand wheels anyway. Realistically, I would not expect them to be repeatable under about 0.02 maybe 0.03mm anyway.

Very happy with them. Given the quality of my mill, they are realistic and well suited. Personally I think the more expensive glass scales would be a waste on a machine such as mine.

Oh, I didn't end up re-installing the end stops for the power feed. I never used them anyway. I never walk away from the mill to ever allow it to crash anyway. I'm always more concerned about the cutter eating my vice, clamps, or a parallel

Simon

Originally Posted by simonl

Hi Dean,

Some time back I purchased a couple of these (or similar to) to use as limit switches on my mill head lift/lower. Dirt cheap and they are reasonable quality. Plenty of other types on ebay.

http://www.ebay.com.au/itm/Industria...09d0239&_uhb=1

I also recently installed a DRO on my mill. Just the cheapie igaging type with the remote readouts. Got sick of counting hand wheels and dealing with backlash. Early days, but I have been very happy. Best thing I have done it the mill so far!

I can post a pic if you want but it's just a stock standard install with the scales protected by being enclosed in aluminium C channel.

Here's what I bought:

http://www.ebay.com.au/itm/Igaging-2...f5daa08&_uhb=1


These look OK. These were not available when I was looking.

http://www.ebay.com.au/itm/Igaging-2...9e7b37f&_uhb=1

My only criticism at this stage is there does appear to be a small amount of hysteresis in the readout when changing direction. It could be my imagination but that's what it seems like. I'm not meaning the backlash either. I'm talking hysteresis to the amount of 0.01 - 0.02mm though so it's still more accurate than I could every achieve with my hand wheels anyway. Realistically, I would not expect them to be repeatable under about 0.02 maybe 0.03mm anyway.

Very happy with them. Given the quality of my mill, they are realistic and well suited. Personally I think the more expensive glass scales would be a waste on a machine such as mine.

Oh, I didn't end up re-installing the end stops for the power feed. I never used them anyway. I never walk away from the mill to ever allow it to crash anyway. I'm always more concerned about the cutter eating my vice, clamps, or a parallel

Simon

Thanks Simon. Last year I had the money to buy a 3 axis DRO from the DRO Shop, but you know what happens with money! I may get a similar one to yours. As soon as I get the time I will get some more work done on the feed system.

Dean