I've owned my 100mm Combo mini mill (no reduction) for almost 4 years
now. It's been well maintained, oiled regularly, kept covered when
not in use and the rollers are in pristine condition. Plus it's only
being used by me. Today while rolling out an ingot of 10 gauge
sterling, at the end of the passthe mill started making a clunking
noise in the area of the extension rollers. I was able to loosen the
Allen nuts holding the plastic cover over the gears and move it
slightly out of the way to observe a small portion of the gears. I
could see a section of gear (a tooth) missing from the upper gear and
it was quite loose on the upper roller. When I tried to put the cover
back on, I couldn't get it back all the way on, the cover gapped at
the bottomon one side slightly and turning the handle made it sound
like something was rubbing against the plastic cover. Has anyone had
any similar experienceswith their Durston mills? I some how don't
think there's supposed to be a section of gear missing.
Since you have used this mill for 4 years I am sure you are aware of
the trials a mill with no reduction gears can have. Smaller bites
are needed so you don't wear your self out or jam up a piece in the
mill. Stuff like that. I think we have a natural impatience that
says to us, "A slightly bigger bite won't kill me." And we tend to
go that little bit beyond the limits of our equipment. Durston is a
great name in shop equipment. Well made and usually easy to use.
If there is a small fault in the casting anywhere over time it will
become apparent with the strain we generate in a rolling mill. I
suspect that is the case with your mill. And some things just wear
out faster than others.
Contact Durston I am sure the parts are available.
I have had a mill for 20 years that came from India, the much
advertised, "Economy Mill". It has a 4 to 1 reduction and even at
that I strain to use it. When I bought it I was torn because for the
same money I could have had a Durston non reduced mill. Mine is a
trooper and it gets the job done. It is limited to how far it open
and I make mainly sheet with it. It is over built in some areas and
that may be the gears. I am more concerned I will break the arm some
day. Mine as well as the mills.
I've posted a video on YouTube showing as much of the interior of
the gear box that I can. One can clearly see the upper gear moving
about and the space where I suspect a tooth is missing. Does anyone
have either a schematic of this mill or have any experience removing
the rollers and the gear box cover? Allen keys don't seem to work in
the key spots.
Durston Rolling Mill inside gear box
If you want us to diagnose your gear problem well need you to do the
1. take off the plastic gear cover
2. photograph whats there with the broken tooth uppermost.
3. remove the 2 gears, they should be keyed to the roller shafts and
put them on some white paper and photo again
4. post these pics here
we'll do the rest.
Now ive a D mill too and theres no way that gears will breakin
normal use, however, if you open the rolls too far the gears could
come out of mesh, 2 teeths chash, and with enough brute force, break
one of the, tho most unlikely.
Await your pics.
How can I share files and pictures with the list?
Or.... send the files to the attention of firstname.lastname@example.org and
we will upload them for you....
OK its Ted here Again,
Ive looked at the video. It seems that the top gear hasnt lost a
tooth it seems to have split along the keyway and opened up.
When you have taken it to bits you will see for yourself. Now
Durston will have spares. They will quote you, or just maybe give
them for free as a gwj to you.
Await the pics.
Sonja the best thing for you to do is contact Durston ASAP, I have a
durston Mill also 6:1 ratio, I had a problem in the first few
months, had tried to roll down too thick a piece of metal, and the
the gears as you show had gotten chewed up, they got right back to me
over a weekend, and within a week I had the parts and instructions
how to replace the gear set, all free of charge, it is a small family
business who are proud to take care of their customer and machines,
just get in touch with them how eve you can, and if cant contact
them don't give up just get them the message and theywill take care,
I am based in US east coast, the company is based outof England, they
were in AZ at the time of my need and they steel made ithappen. as a
company with great customer service I am a happy customer when they
show me that kind of dedication. Good luck to you.
I thought I had a simular problem but on a closer look I had just
openned the rollers too far. Try closing
the rollers and then see if the gears mesh correctly.
Yeah, be careful of that arm. I got one of those cheap Indian mills
at a garage sale once, specifically because the arm had snapped.
Oh My. Looks like the gear itself is busted. I say this because I'm
reasonably certain that I can see the underlying shaft as you wobble
the gear around. And the gear itself couldnt't move the way yours
does if it were still intact, just missing a tooth. So that's a
whole lot more serious than just fixing a tooth, it's time for a new
gear. Contact Durstons, and see about acquiring one. This isn't
something you could fake up at home. Check the other gear to see if
the first one trashed it as it was going. With damage like what
you're showing, that's a real possibility. (So you may need two
I think you can get that plastic cover off after you remove the
outboard rollers. If memory serves, they're retained with spring
rings, (circlips). Stick the ends of a pair of double round pliers
into the holes in the ends of the clip, and open (close) the pliers
in whichever direction seems appropriate to open the clip to the
point where you can get it off. Then the rollers just pull off.
(If you have circlip pliers, great, use those. But double rounds
will work in a pinch.)
Definitely time to contact Durstons.