Due to old age creeping in, it is becoming increasingly difficult to take heavy items up & down stars.
I intend modifying my two wheel dolly to a stair climber.
I would like to get some definitive measurements for the wheel size and arc radius.
If anyone should own one, maybe could post the Dims?

 

I do not have one of those but I have seen them work very well.
If you have a two wheel dolly you know they don't like stairs.
What I have looks like this. The belt on is an automotive fan belt. Put on the reverse of the picture. There are two pullies, one top and one bottom.
When you tip the dolly back the wheels do not touch the stairs, just the belt.

 

If you put a "Stare Dolly" looking down from above, you just may not want to go up the stairs at all!

 

The ones I used were like Ron's except they had a ~3" wide belt on each side of the frame but same concept and worked well. Not great but ok and helps to have someone on the low side to give a bit of extra oomph when lifting big and heavy stuff (refrigerators/freezers) over the edge and steadying it so it doesn't roll off the step when resting which is often. Never seen one like you showed Max.

 

Is it that time to build a dumbwaiter, max?

 

Due to old age creeping in, it is becoming increasingly difficult to take heavy items up & down stars.

Is this so someone can haul you up the stairs?

 

Is this so someone can haul you up the stairs?

Probably getting that way!

 

Is it that time to build a dumbwaiter, max?

Actually I had thought of that recently, that I regretted not putting one in when I moved in here some decades ago.
But you never anticipate some things eventually happening.

 

We used to live in a 2 story house...

But as we were getting older, and all the living was up stairs, we sold it and moved to a single level house.
It was really obvious after a grocery shopping spree, and then having multiple trips up stairs carrying bags of goodies. The knees would complain. Where we live it is pretty flat so we do not eve get exercise going up and down hills. At one time I did toy with the idea of installing an elevator in the stair well but the cost would have been too high. Our "new" home is great but I do miss the old one some times.

 

Our house have four levels including the basement. For now, I don't have any trouble with moving things up and down (including myself) but those times when I have to go from the basement to the third floor it definitely provokes thoughts about a future where I will have to spend a lot more time making it all the way up the three flights of stairs if I need to make that whole trip.

It is also likely I will not be carrying the same load I can do now. I already quietly dread that day every month or two when I will have to carry several 40 pound bags of softener salt from the first floor to the basement. Conveniently, when it simply must be done because the salt has been living in the kitchen too long, one of my sons just happens to be here... Weird how that works out...

 

aka Running barrow, Sack truck
I have one at work, it has 140mm wheels, with 105mm offset between the wheel centre and the axle around which the wheel assembly rotates.
It can move a 200kg emergency lighting unit up stairs. You would be surprised how many people think it is such a great idea to put a plant room containing emergency lighting unit and a tonne of batteries up stairs.
Because it has four wheels in contact with the floor, and none of them can steer, it’s good in straight lines, and doesn’t corner well.

 

Proper instruction for old ages :"
https://www.imdb.com/title/tt7405458/