Ballscrews?

[John HaineParticipant @johnhaine32865]

Well, SOMETHING has to take the weight, what is it if it isn't the floor? Or are we expecting anti-gravity?

[Andrew TinsleyParticipant @andrewtinsley63637]

Excellent suggestion Baz! I have just reinforced my loft floor and it was a straightforward and surprisingly inexpensive job..

The obvious way to go, simpler and cheaper than complex weight bearing devices that must weigh next to nothing. Makes me think of skyhooks!

Andrew.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Bear G 1 on 29/05/2019 12:29:19:

Posted by HOWARDT on 29/05/2019 11:53:14:

…

You are intentionally misunderstanding what I have written. THE FLOOR CANNOT TAKE THE WEIGHT.

I have to build this then ensure the beams don't deflect more than they are already…

Bear

I think the floor and beams are the first problem rather than the nature of any screw used to work a scissor jack.

Is this in an attic, perhaps a loft conversion? If so the 'floor' may be considerably weaker than that installed in a bedroom. And in turn, a domestic bedroom floor is usually weaker than an office floor, let alone a warehouse.

What is and isn't possible is a job for a structural engineer. He would look at beam dimensions, the nature of floor covering (planks or sheet), the materials used, and the overall construction. My parent's 1930 house has closely spaced pine rafters each about six times heavier than those in my 1970 palace, plus all their internal walls are load bearing whilst most of mine aren't.

It's important watch the Building Regulations; a relative installed an unwise loft conversion and had gigantic problems with surveyors, his building society, the building inspector and insurance when he needed to sell the house. Ended up having to return the loft to it's original state. £thousands.

Anyway, if you're determined to go it alone, a rule of thumb is to make sure the floor does not deflect by more than the building regulations allow, which varies. But in the US it is often the length of the beam divided by 360. Thus a 4 metre span floor is not to deflect by more than 11mm. More than that is unsafe.

Thing about the scissor or any other lift is to work out where the weight is going to go. It may be possible to reduce the floor deflection by spreading the load, often done with a large sheet of thick plywood. But note that the plywood itself is heavy. Another approach is to put a pillar underneath. A third is to transfer the weight sideways into the walls, in effect by building an arch bridge. The problem with bridges is that they put a massive sideways load on the walls, which, because they're not designed to take side loadings, will break. A builder would probably just strengthen the floor, perhaps by replacing wooden rafters with steel girders.

Once the floor is fixed, lifting 300kg isn't horrible difficult.

Dave

[Bear G 1Participant @bearg1]

Unfortunately fixing the floor isn't an option.

To those presenting me with ideas; I'm afraid ALL these ideas have already been looked at and dismissed the four post lift idea was my first and failed on how the hell drive could get to them and having an unsupported ten foot span would be a huge problem. A scissor lift is the ONLY possible way of doing this.

Using two ballscrews to spread the load is doable.

Bear

[Andrew TinsleyParticipant @andrewtinsley63637]

Maybe it would have been a good idea to have solved this problem BEFORE you built your layout. Sounds like very poor forward planning.

Andrew.

[Jeff DaymanParticipant @jeffdayman43397]

Starting to get concerned about liability for responding members – the OP has indicated the floor he is loading will not take the weight he plans to lift, but is planning to use a scissor lift anyway. It seems very dangerous to me to be considering any lifting device if the structure it is to be used in has borderline strength for the job.

Please don't risk your safety and risk a structural collapse to do something on a model railway.

[Bear G 1Participant @bearg1]

Andrew, this is the solution to the problem! I've got a skylight cutting right through where I want to run point "fans". I tried building it like this but it was doomed to fail because the other end is a toilet/shower cramping what space there is meaning some roads were too short and some of the junctions were impracticable but worst there weren't enough roads.

What I'm building has a forty eight road capacity in far less space than anything traditional.

Please don't post in my threads again, your opinion is utterly worthless to me.

Jeff, the floor has sagged due to the weight of crap stacked on it for the last thirty years. The "eviction" will begin soon but what goes there instead must be lighter.

Bear

Edited By Bear G 1 on 29/05/2019 22:33:09

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Bear G 1 on 29/05/2019 12:29:19:

THE FLOOR CANNOT TAKE THE WEIGHT.

… I've been researching for months and what I'm trying to build is the only way it can be done.

Bear

.

Let's take another look …

The floor cannot take the point loading

But, hopefully, it can take the weight, if adequately distributed

Have you, in your months of research considered using 'air bag' jacking ?

MichaelG.

.

Start here: https://www.rentlgh.com/product/air-bags/

Edited By Michael Gilligan on 29/05/2019 22:34:13

[Bear G 1Participant @bearg1]

Michael,

This is why there are to be forty eight supporting feet. This should distribute the weight safely especially when I get rid of old kitchen cupboards full of crap that havent been touched for twenty years.

Bear

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Bear G 1 on 29/05/2019 22:38:57:

Michael,

This is why there are to be forty eight supporting feet. …

.

Yes, but … "Have you, in your months of research considered using 'air bag' jacking ?"

MichaelG.

[HopperParticipant @hopper]

So why the aversion to using plain old-fashioned, readily available, not-too-expensive, stout-enough-for-the-job, reliable, self-locking Acme-threaded rod and solid nuts, which is what is commonly used for scissor lift applications?

If you simply must have ballscrews (they are rather sexy aren't they), there is some info on the DIN standards and load calculations etc here *LINK*

Edited By Hopper on 30/05/2019 00:44:21

[Michael GilliganParticipant @michaelgilligan61133]

Excellent reference document, Hopper … Thanks for the link.

MichaelG.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Bear G 1 on 29/05/2019 21:17:34:

Unfortunately fixing the floor isn't an option.

To those presenting me with ideas; I'm afraid ALL these ideas have already been looked at and dismissed the four post lift idea was my first and failed on how the hell drive could get to them and having an unsupported ten foot span would be a huge problem. A scissor lift is the ONLY possible way of doing this.

Using two ballscrews to spread the load is doable.

Bear

Bear,

If strengthening the floor isn't an option, fixing it if it breaks is?

Problem is that having eliminated all the alternatives, you're now finding that the forum doesn't like the scissor lift idea either. Particularly a scissor lift built from ball-screws and CNC thread! On top of that are a lot of unknowns, like the load capacity of the floor.

From what you've described it sounds like a 'How do I get a quart into a pint pot' problem. My workshop is in a single garage and it doesn't matter how much I want them, I can't install a bigger lathe, a bigger mill or a bigger bench!

We're not trying to put you off for the sake of annoying you, it's just that from this side of the internet the solution looks iffy, perhaps dangerous.

Sorry

Dave

[HopperParticipant @hopper]

How do you get a weight of 300kg to be lifted on a miniature train board?

Is it something like this?

 

Does not look like 300kg in a sheet of ply and some aluminium framing, but not sure what exactly your plan is compared with the above example.

 

Maybe you would be better off doing something like the above, where the yard is in multi-levels but instead of lifting the whole board up and down, just the one train in use is either lifted, spiralled or simply inclined up to the main board level?

 

 

 

 

Edited By Hopper on 30/05/2019 08:33:25

[Douglas JohnstonParticipant @douglasjohnston98463]

Posted by Bear G 1 on 29/05/2019 22:28:45:

Please don't post in my threads again, your opinion is utterly worthless to me.

For a person with only 9 posts you sure like making a good impression with members here.

Doug

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Douglas Johnston on 30/05/2019 08:46:14:

For a person with only 9 posts you sure like making a good impression with members here.

.

… at least he said please; which is an improvement on some.

That said: I believe that a forum is, by definition, open to all members and no-one has the right to call a thread 'mine'.

MichaelG.

[not done it yetParticipant @notdoneityet]

I am surprised anyone is now replying. Nine posts on the only thread and likely never to continue. Has ignored virtually all the advice offered and been impolite, too. Totally blinkered, IMO.

Best course of action is to let him get on with it without agreeing with him on anything – and hope he never makes the news for the wrong reasons. Likely take you to court for wrong advice, too, if he survived the accident waiting to happen?

[BazParticipant @baz89810]

NDIY totally agree with you, let him do it his own way because he knows best. Loved his earlier comment about all the toolmakers he knew who could make a simple job difficult, shows he knows b***er all about engineering. Fact of life that if you wish to lift 300kg off the ground the lift must be strong and therefore heavy enough to support the weight, I have a 300kg lifting table to move my locos and the table is heavy, I cannot pick it up, but if our friend thinks he can make one that weighs next to nothing best of luck to him, I shall not post any more on this subject.

[Former MemberParticipant @formermember32069]

[This posting has been removed]

[Bear G 1Participant @bearg1]

Posted by not done it yet on 30/05/2019 09:44:20:

I am surprised anyone is now replying. Nine posts on the only thread and likely never to continue. Has ignored virtually all the advice offered and been impolite, too. Totally blinkered, IMO.

Best course of action is to let him get on with it without agreeing with him on anything – and hope he never makes the news for the wrong reasons. Likely take you to court for wrong advice, too, if he survived the accident waiting to happen?

I've been impolite to people who were the same to me.

I've investigated ALL ways this could be done and chosen the ONLY possible solution. This is NOT blinkered at all! I've spent an awful lot of hours looking at different ideas nearly all of which have been presented to me in this thread.

I've NOT ignored advice. I'm looking at ballscrews because of the far lower torque needed to start compared to other systems. I fully understand that when they get badly worn they can fail but the operating words there are badly worn.

Your frankly bonkers assumption that I would sue for getting bad advice and having an accident…WHERE DID THAT COME FROM???? You know NOTHING about me so who exactly are you to judge how I would respond or react???? If there is one thing that really angers me it's judgemental people.

I've spent my entire life being judged as stupid, retarded, a freak and a both physical and verbal punching bag. So the best advice is DON'T POST something that I might react badly to; I no longer bite my tongue and stay quiet and I am not afraid to say how I feel about something or someone. Yes, I would say it to your face.

And to Baz; I went to college and got an engineering qualification. My comment about toolmakers was something THEY SAID TO ME. I know an awful lot more about engineering than you think, been around machines since I was a child.

To others who are trying to help; 300kg is theoretical but I am not one to make something that breaks/fails. The traverser part is complete on a wooden frame the tiered section also wooden. I cannot weld but I can make lots of sawdust! Made an awful lot of swarf on this project too…

Hopper, That is interesting, thanks for the link. It is similar but mine has rise and fall and zero electronics. I have looked at inclines but there just is not the space there. I have previously built helix's but they have the disadvantage of huge drag limiting the length of train you can run (I'm aiming for scale length).

There is a product called a Nelevator but I'm trying to avoid electronics in what I'm building.

Bear

 

Edited By Bear G 1 on 30/05/2019 11:04:40

[Former MemberParticipant @formermember32069]

[This posting has been removed]

[HopperParticipant @hopper]

Posted by Bear G 1 on 30/05/2019 10:59:19:

If there is one thing that really angers me it's judgemental people.

You should look deeply into that statement.

[duncan webster 1Participant @duncanwebster1]

changed my mind, not worth responding

Edited By duncan webster on 30/05/2019 12:44:57

[Bear G 1Participant @bearg1]

Posted by Hopper on 30/05/2019 12:06:27:

Posted by Bear G 1 on 30/05/2019 10:59:19:

If there is one thing that really angers me it's judgemental people.

You should look deeply into that statement.

I respond in the way I've been conditioned to respond. So far in this thread one person has lodged a mild personal attack so was told how I felt. Two others have decided that it is perfectly OK to launch full on personal attacks something I have not done to them which I consider the definition of cyber bullying. I remember laying on the floor surrounded by a group of bullies using me as a football and what those on this thread did felt exactly like that to me.

Bear

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