Repairing a 100 year old rolling gate - any advice?

fiddlefye

Senior Member
So, given that this is an audio forum why the heck am I posting about this? Well... there are lots of bright sparks on the forum with a ton of knowledge to draw on and maybe some ideas how to source a solution to a problem. So here it is.

We have one of those older homes (110 this year) that has a functional back alley where the garbage gets put out etc. The back fence and roll-away gate was installed sometime in the early 1920s and while parts have been deteriorating on a continuing basis for decades things have finally reached the point where "quick fixes" aren't enough.

As you can see the gate is huge and weighs a ton. It has a roller set up on the right hand (opening) end on the ground which is still ok and has undoubtedly been replaced a few times over the years.
_ND30770.jpg
The main weight of the gate is supported in a channel with two support points, each with a double roller. Originally the flange that the rollers attach to was welded to the arm, but sometime very long ago the welds broke off when the cement below settled to a lower level. In the second photo you can see the remains of the original welded installation just under the present strapping.
_DSC2167.jpg_DSC2168.jpg
As you can see a bit of MacGyver approach has been taken to support the gate and it works ok, though I have had to replace the sheet metal strapping every few years as it rusts and fatigues. Lately the roller assembly on the left has decided to twist and just drags and no amount of putting it straight accomplishes anything.

Inside the channel track are two roller assemblies and they really are completely shot. There are ball bearings in there, but with half of the balls missing. Even the wheels are getting worn out. Worse yet, I can see no way of disassembling things to replace the bearings, my initial preferred approach in spite of the worn wheels.
_DSC2169.jpg_DSC2170.jpg_DSC2171.jpg_DSC2172.jpg
So, given I can't find any way to take the assembly apart I guess I'll have to find some means of duplicating it (times two).

I've put the calipers to things and here are the dimensions I get - in millimeters, though undoubtedly originally in inch units.

Wheel outer diameter - 47mm
Wheel width - 16mm - overall diameter of 40mm for the pair
Shaft diameter - 12mm
Bracket/flange - H - 72mm x W - 60mm x thickness - 5mm

So here is the question - where an how would anyone suggest I go about getting duplicate assemblies made? While I can see what is needed I really have no idea where to start.

Suggestions?
 

JP

Junior Member
Looks like the width is narrower but that may not matter depending on the channel opening. Also possible to insert a unistrut in to the existing channel.

On the other hand, flat piece of metal, two bearings, and a shaft would get you in business. You wouldn’t need to secure the bearings on to the shaft as your channel would keep it all together. You’d just need to have something between them to space them out.
 

fiddlefye

Senior Member
Looks like the width is narrower but that may not matter depending on the channel opening. Also possible to insert a unistrut in to the existing channel.

On the other hand, flat piece of metal, two bearings, and a shaft would get you in business. You wouldn’t need to secure the bearings on to the shaft as your channel would keep it all together. You’d just need to have something between them to space them out.
The biggest problem is finding suitable wheels perhaps. Whether the narrower width would matter that much is a good question. It hadn't occurred to me to insert a completely new strut into the original, but that would sure make things run smoothly. The existing channel is much bigger than what I'm seeing as currently available.
 

fiddlefye

Senior Member
You don’t need wheels - the bearings are your wheels.
They'd still need to have some width to run on, though? The big shop in town where I used to buy bearings (all they sold) closed up last year. Dang.

Maybe a couple of these four-wheeled ones would actually be better as it would deal with any desire to twist in the existing track much better? Unistrut P2950 Four Wheel Trolley – 1-5/8″ Channel Fitting

Of course one problem with buying anything is finding a source in Canada or talking someone into shipping the danged things. When one looks for something like this almost all of the "hits" turn out to be in the US and unless I want 1,000 of the things they'd rather not ship them to me...
 

JP

Junior Member

Not sure how much the diameter is going to matter in your application Found this with a quick search from my phone.

Is the running surface of the channel flat or concave? If flat then a four-wheel trolley could be better. If concave then a two-wheel with convex bearing should run true.
 
I say its a poor design to start with.
You might consider converting it to a tru cantilever design or a simple track gate.
The trolley design can't support the gate.
A track gate has a track on the ground that runs the full lenght of travel. The bad part is you have track across he opening.
The track is an upside down angle iron and it supports the gate, you just have two guides at the top to keep it upright.
A true cantilever gate needs the extension on the rails to be 1.5 times the length of the gate opening . Two rollers top and two rollers bottom. As it rolls it only uses one roller at the top and one bottom roller at the opposite end, about half way through t it's travel the weight shifts and now the other two opposite rollers bear the load. It only rolls on two at any given point.
 
The big shop in town where I used to buy bearings (all they sold) closed up last year. Dang.
Which one was that?

I checked a few--Motion Industries only has a branch in Sarnia and two in London, the closest to Windsor. Canadian Bearings, BDI Canada and LSI Supply would probably quite a few selections among them. We have a few branches on our side of the border (Applied, Motion Industries, Bearing Service, etc.) but the border is a no-go right about now. I'm very wary about mail order since so many no-name or off-brand parts are sold online, and they are poor quality (Chinese bearing steel is...not good).

For the type of cam roller (track roller) bearings that @JP listed, INA is one such name brand manufacturer, and there are probably others out there of decent quality. If I had access to my old catalogs, I could have tried to find something close in size. Off the top of my head, the thicker version of what @JP posted, an LR5301NPPU (the letter suffix is for rubber seals), is a larger cross-section and closer to your original dimensions (12mm ID, 42mm OD, 19mm W). It has the crowned outer race that could be used in your application.
 

fiddlefye

Senior Member
I say its a poor design to start with.
You might consider converting it to a tru cantilever design or a simple track gate.
The trolley design can't support the gate.
A track gate has a track on the ground that runs the full lenght of travel. The bad part is you have track across he opening.
The track is an upside down angle iron and it supports the gate, you just have two guides at the top to keep it upright.
A true cantilever gate needs the extension on the rails to be 1.5 times the length of the gate opening . Two rollers top and two rollers bottom. As it rolls it only uses one roller at the top and one bottom roller at the opposite end, about half way through t it's travel the weight shifts and now the other two opposite rollers bear the load. It only rolls on two at any given point.
It might be a poor design, but it is one that has been exposed to the elements and in constant use for a century so how bad can it be, really? Taken as a whole it has stood up rather well, all considered. As it stands now the weight is distributed at three points throughout the entirety of the travel.
 
You might be able to rig something up with some wheels found here. :)

 

fiddlefye

Senior Member
N
So it has a bottom track?
Couldn't see that in the photo on my phone.
No bottom track, but two sets of rollers on top spaced about six feet apart on the arm portion that runs in the track and one big set of wheels on the ground at the far right end of the gate. A track on the bottom would be a disaster as it would fill with snow and ice in winter and be very hard to keep clear. The gate would basically be stuck shut for weeks at a time. Bad enough keeping the wheels on the ground movable in winter.
 

BillWojo

Junior Member
This was a common item used on barn doors as long as I can remember barns. Maybe a company like Tractor Supply or any company that offers supply's for a farm/ranch would have what you need.

BillWojo
 

fiddlefye

Senior Member
When the rain stopped I went out and had a closer look at the channel and took some measurements.
_DSC2181.jpg
The width at the top is 2.5" (63mm), the height is 2" (50mm). The areas where a roller would ride are flat and 1/2" (13mm) with the space between being .8" (20mm).
_DSC2182.jpg
_DSC2183.jpg
 
Top