Request for plans/pics/tips: MacDonald Mill

Overmountain

Overmountain

Joined
May 2, 2013
Messages
1,711
I have a copy of the original plans. Albeit a very grainy copy...

What I'd like specifically is this...

As stripped down of a version as anyone has found good and workable.

Anyone who has used a gear reduction drive as opposed to the multiple pulleys to step motor speed down. I.e. what reduction ratio to what motor size and roller dimensions did you use and what's the feed like.

And I want feedback because I hear two different stories on using mild steel rollers versus hardened steel.

And not trying to sound arrogant or mean but please as direct anecdotal evidence as possible please, not what you heard from a guy one time at a thing.

Thanks.

-Eric
 
Thanks Kosa but that's the exact set I have printed out.

What I'm looking for is using gear reduction vs pulleys. Any issues or problems, power concerns or the like for doing so.

I'm eliminating the whole handle and cam thing he designed in. It just isn't necessary with a longer pedal and a screwjack that is easily spun. I'm a big boy (6'1" 250#) so I can put some pressure on it beyond what he accounted for on the original anyway. So I think I can get away with a little more aggressive ratio.

Rollers, going to do the usual and turn the ends of some 3-4" to fit a larger pillow block. I have 1018 steel available in 3" diameter and have heard there were no problems seen with using it for the rollers. If I could use that it would save me some time at the lathe and some money over using 4140 which is also available from my local source. Would like to come up with an interchangeable roller system to have patterns atnmy disposal obviously. I know 1018 will suffer some pattern erosion in that application so they would have to be hardened steel...

I had an ambitios idea to do this combination air over hydraulic press and rolling mill combo on the same frame but it wound up cluttered looking and inefficient in renderings. Too bad because it would have been cool...
I have a good 3/4hp motor to use on it. From what I've heard that should be plenty. If not, LMK.

-Eric
 
I have worked on one that had a gear reduction motor and mild steel rollers. the only thing controlling the bottom jaw was the jack screw. had good power was a pain in the a&& as well as the back stooping over to turn the screw every pass and the mild steel rollers deformed after a fairly short time. I would buy hardened 4140 for the rollers and at least put the foot pedal in. or a hydraulic motor and ram to run the rollers and adjust the jaws for thickness.
 
1,5kW gear motor with 25RPM (with 430Nm) + footswitch will be good for this roller mill?
And I also need better plans for making this :( ( A dream is DXF/DWG file )

And better that a screw thickness regulation is to put there a small Hydraulic lift with 5-10 tons lifting capacity ?
 
Last edited:
Bill Burke said:
I have worked on one that had a gear reduction motor and mild steel rollers. the only thing controlling the bottom jaw was the jack screw. had good power was a pain in the a&& as well as the back stooping over to turn the screw every pass and the mild steel rollers deformed after a fairly short time. I would buy hardened 4140 for the rollers and at least put the foot pedal in. or a hydraulic motor and ram to run the rollers and adjust the jaws for thickness.
Click to expand...
Thanks Bill
That's what I wanted. You hear 'sure, mild will be fine' but I was doubtful. Doing the math, and considering the fact all that force bears down on a very small area between the rollers, and is unbridged by anything but the roller's diameter, I had a feeling they'd end up out of round at some point.

I am doing the foot pedal and a cam of sorts, just not his original with the mutiple steps with the handle to step it back up each or every couple of passes. I get the idea, it just appears with a pedal 1 1/2' off the deck I lose heat before I get more passes in than there is vertical movement in the lever without having to step it back up each time... Maybe not. It wouldn't be that hard to just include it I guess...

A colleague and I did a standard pass through roller earlier this year. It couldn't take very big bites and both rollers were powered. Hence why I think the lever is overkill in the adjustment department. And I'm going to be doing flat stock with it more than round bar, so spreading out the force and not getting as much juice with each squeeze.

-Eric
 
Eric,

I really like having the lever on there after having used one with and one with out. the only thing I might do different than the plans with the lever is to make more smaller steps. adjusting the final thickness you want with the lever. then simply moving the lever from its forward position back each notch at a time and being able to push the pedal down to where it just starts to cam over gives you more mechanical advantage. and you don't have to bend over after every pass to adjust the jack screw to close the jaws. just set for final thickness then when the lever has reached the rearmost notch and the foot pedal is all the way down your steel is the thickness you wanted easy peazy no dickin around trying to measure a hot piece of steel especially if it is a long piece.
 
Bill Burke said:
Eric,

I really like having the lever on there after having used one with and one with out. the only thing I might do different than the plans with the lever is to make more smaller steps. adjusting the final thickness you want with the lever. then simply moving the lever from its forward position back each notch at a time and being able to push the pedal down to where it just starts to cam over gives you more mechanical advantage. and you don't have to bend over after every pass to adjust the jack screw to close the jaws. just set for final thickness then when the lever has reached the rearmost notch and the foot pedal is all the way down your steel is the thickness you wanted easy peazy no dickin around trying to measure a hot piece of steel especially if it is a long piece.
Click to expand...
Fair enough. Will put it in. Thanks again Bill.

-Eric
 
LucyCustomKnives said:
Fair enough. Will put it in. Thanks again Bill.

-Eric
Click to expand...

I don't think you will regret it. I know my back ached for three days after spending a day stooping over every 15 seconds to adjust a jack screw. roll adjust roll adjust roll adjust reheat adjust roll etc.... pain in the ass too.
 
How large of a pillow block bearing did you find ?

I found the sizes stopped pretty small, but I didn't look too hard.
 
OK, so let's summarize:
1. Lever with more latches, ( 2x ? )
2. Bridge above of the bearing.
3. Plain bearing from phosphorous bronze (Bronze B101)
4. Hardened rollers from hot working steel

Btw. Someone have this design in CAD?
 
12345678910 said:
How large of a pillow block bearing did you find ?

I found the sizes stopped pretty small, but I didn't look too hard.
Click to expand...
That has been another source of debate... How large the pillow blocks really need to be. I have from 1" up to 2" blocks from a local mining equipment supplier/friend. Those are cheap (as in a case of beer...) so if they're enough (the 2"), I'm gravy. I would think so, they are heavy duty rated blocks.

Aside from that, there is bearing source which has them all the way up to 7":eek:
The prices are ridiculous though. Fastenal has/can get 2 1/2" I think the guy said?? They were over $200 a piece though. Not really saving money there.

The 7" blocks are $4400 a piece BTW:eek::eek:... Lol. I'd like to just hold one of those bad boys...

-Eric
 
when I first built mine I had pillow blocks with ball bearing in it and they ended up breaking from the pressure. the outer race split right down the center, I can only surmise that the pressure exerted wedged the balls into the race until it split. I found a pair that had opposing roller bearings in them and had no further trouble.
 
I've noticed that as one of the main differences between really heavy duty bearings and the rest. All the really hefty ones use roller bearings.

What diameter did you run?
 
OK, I starting making my own roll mill based on plans from here :)

But I will use Hardened rolls from 1.2714 (WNL) from Bohler

And B101 bronze bearings :)

For Heavy duty, the best are slide bearings.
 
You must log in or register to reply here.
Back
Top