Good afternoon!

I have some box section stainless steel, which needs to be cut and
electrically welded to make a lifting frame work. I am not concerned
about rusting of the weld, so will ordinary mild steel welding rods
weld this OK?

A length of mild steel 8mm galvanised threaded rod, is this capable
being used to lift and safely supporting say around 250kg?

It is a single post type motorcycle lift I am building by the way.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Harry Bloomfield" wrote in message
...
Good afternoon!

I have some box section stainless steel, which needs to be cut and
electrically welded to make a lifting frame work. I am not concerned about
rusting of the weld, so will ordinary mild steel welding rods weld this
OK?

No!
Get it properly welded by a person with a good TIG welder.

A length of mild steel 8mm galvanised threaded rod, is this capable being
used to lift and safely supporting say around 250kg?

No again.

Find a suitable D shackle and bolt or weld it on.
Studding is inherently liable to break at the weakest point in the thread,
which might just be the point you are using to lift with


It is a single post type motorcycle lift I am building by the way.

Why stainless then?
Unless you have access to some for nothing that is ;-)

Personally I'd use 50mm square 3mm thick MS Box section, a good arc welder,
some Eutectic(sp?) rods, and a portable chop saw for metal to cut
accurately.
As for the lifting part I stand by my shackle approach or alternatively a
13mm re-bar bent to shape then passed through the main frame and welded each
side.
I made a heavy duty engine hoist attachment for a single post lift a while
back like this ( Lorry engines) and it worked very well.
For private use there's little point in having it tested, although testing
it to double the weight expected to lift would be a good idea before using
it even for your own peace of mind.
If being used in a "shop" or commercially it is subject to the Loler
regulations.

After serious thinking R wrote :
"Harry Bloomfield" wrote in message
...
Good afternoon!

I have some box section stainless steel, which needs to be cut and
electrically welded to make a lifting frame work. I am not concerned about
rusting of the weld, so will ordinary mild steel welding rods weld this OK?

No!
Get it properly welded by a person with a good TIG welder.

Being a little pushed for time - I've just built up and tested the
lifting frame part. 1.75" square for the end bits, 2" square for the
main spar, all 3mm wall - It's basically a frame which slides under the
wheels like an 'F' at each end linked by the 2" x 2". I managed to test
load the frame up to 2.25 tons, at which point my welding snapped,
rather than the box section. So I'm reasonably satisfied with that
first part.

A length of mild steel 8mm galvanised threaded rod, is this capable being
used to lift and safely supporting say around 250kg?

No again.

It has to be a self contained screw lift of some sort - I'll have to
rethink that part.

Find a suitable D shackle and bolt or weld it on.
Studding is inherently liable to break at the weakest point in the thread,
which might just be the point you are using to lift with


It is a single post type motorcycle lift I am building by the way.

Why stainless then?
Unless you have access to some for nothing that is ;-)

It is some stainless I acquired before it was taken for scrap.

Thanks...

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Harry Bloomfield" wrote in message
...
Good afternoon!

I have some box section stainless steel, which needs to be cut and
electrically welded to make a lifting frame work. I am not concerned about
rusting of the weld, so will ordinary mild steel welding rods weld this
OK?

A length of mild steel 8mm galvanised threaded rod, is this capable being
used to lift and safely supporting say around 250kg?

It is a single post type motorcycle lift I am building by the way.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

You can adequately arc weld it. you want stainless or disimilar rods

snipped

It has to be a self contained screw lift of some sort - I'll have to
rethink that part.

snipped

It is a single post type motorcycle lift I am building by the way.

snipped
=======================================

You might consider something like this:

http://www.axminster.co.uk/product.a...sfile=1&jump=0

but I would suggest that you use a standard hydraulic jack if at all
possible.

You might also look at this for some ideas:

http://www.machinemart.co.uk/shop/ca.../vehicle-lifts

You might also consider the kind of one-lift jacks used on F1 cars which
(as far as I know) use only a single lever to achieve lift.

Cic.



--
================================
Testing UBUNTU Linux
Windows shown the door
================================

Cicero used his keyboard to write :
snipped

It has to be a self contained screw lift of some sort - I'll have to
rethink that part.

snipped

It is a single post type motorcycle lift I am building by the way.

snipped
=======================================

You might consider something like this:

http://www.axminster.co.uk/product.a...sfile=1&jump=0

Too short, it needs to raise it by around 25 inches.


but I would suggest that you use a standard hydraulic jack if at all
possible.

I did consider using one, but there is just no room to get one in.

You might also look at this for some ideas:

http://www.machinemart.co.uk/shop/ca.../vehicle-lifts

I already have one of their small lifts - the one designed to lift a
bike via its frame, but they don't work at all with a sports bike due
to the lack of under frame members and lack of clearance. The table
lift type needs lots of room to enable it to be used and stored - which
is where a compact single post lift wins.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Harry Bloomfield" wrote in message
...
After serious thinking R wrote :
"Harry Bloomfield" wrote in message
...
Good afternoon!

I have some box section stainless steel, which needs to be cut and
electrically welded to make a lifting frame work. I am not concerned
about
rusting of the weld, so will ordinary mild steel welding rods weld this
OK?

No!
Get it properly welded by a person with a good TIG welder.

Being a little pushed for time - I've just built up and tested the
lifting frame part. 1.75" square for the end bits, 2" square for the
main spar, all 3mm wall - It's basically a frame which slides under the
wheels like an 'F' at each end linked by the 2" x 2". I managed to test
load the frame up to 2.25 tons, at which point my welding snapped,
rather than the box section. So I'm reasonably satisfied with that
first part.

AH!
So it's an end lift not an entire lift the bike from the top styleee.
At least the welding held out to 5 times what you needed


A length of mild steel 8mm galvanised threaded rod, is this capable
being
used to lift and safely supporting say around 250kg?

No again.

It has to be a self contained screw lift of some sort - I'll have to
rethink that part.

So is it sort of looking like a car spectacle lift with a centre mounted
lift ?

I reckon a "Hi-Lift" (Landrover clubs use em a lot) would be good for this
with a little adaption on the base for stability
See EBay item
120104386063


Find a suitable D shackle and bolt or weld it on.
Studding is inherently liable to break at the weakest point in the
thread,
which might just be the point you are using to lift with

It is a single post type motorcycle lift I am building by the way.

Why stainless then?
Unless you have access to some for nothing that is ;-)

It is some stainless I acquired before it was taken for scrap.

Heh....always worth saving stainless even if just to weigh it in later

On 2007-04-08, 11:09 Z, in news:mn.42d97d7402f2403b.
,
Harry Bloomfield wrote (paraphrased):
Is a 635 mm length of 8 mm mild steel galvanised threaded rod
capable of lifting and safely supporting say around 2450 N? It is
a single post type motorcycle lift I am building. It has to be a
self-contained, compact, single-post screw lift of some sort. It
needs to raise it by around 635 mm.

Harry: An M8 x 1.25 mild steel threaded rod (property class 4.6)
subjected to only axial tension, with no applied bending moment nor
applied shear load, can withstand a static, allowable, applied
tensile load of 4400 N, with no onset of yielding in the threads, if
the nut isn't torqued beyond 5.5 N*m. This means it can support a
gently-applied (not bounced nor suddenly dropped) allowable mass of
448.7 kg in tension.

An M8 x 1.25 mild steel threaded rod (property class 4.6) in axial
compression, having an unsupported length of 635 mm, constrained
against rotation at one end and free to rotate and translate
laterally at the other end, can support an allowable, concentric,
axial compressive load of 522 N. This means it can support an
allowable mass of 53.2 kg in compression.

To support a concentric compression load of 2450 N, a mild steel
threaded rod of length 635 mm would need to be an M20 x 2.5 thread,
which would actually support an allowable, concentric compressive
load of 2918 N. This means it would support an allowable mass of
297.5 kg in compression.

It happens that R formulated :
So is it sort of looking like a car spectacle lift with a centre mounted lift
?

That's the sort of idea, except the specs are open at one side to allow
them to be pushed under the wheels prior to lifting. The vertical post
sits alongside the bike at around the mid point, with its frame passing
both under the bike and under the specs.

The other post about the specification for 8mm rod, suggests using that
might well be possible after all.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

David H. Neumann wrote on 10/04/2007 :
Harry: An M8 x 1.25 mild steel threaded rod (property class 4.6)
subjected to only axial tension, with no applied bending moment nor
applied shear load, can withstand a static, allowable, applied
tensile load of 4400 N, with no onset of yielding in the threads, if
the nut isn't torqued beyond 5.5 N*m. This means it can support a
gently-applied (not bounced nor suddenly dropped) allowable mass of
448.7 kg in tension.

It would be in tension supporting and lifting the bikes weight of 200Kg
plus around 30Kg or so for the frame part which moves. A welded on to
the rod nut at the top, passing through a bracket at the top of the
main lifting post, then a captive second nut pulling on the actual
lifting frame with the bike sat on it. Turn the top nut and the rod
screws into the lower nut pulling up the frame. The only loading apart
from the weight is that of turning the rod to achieve the lift.

It sounds as if 12mm would be a more suitable size to give an extra
margin.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On 2007-04-10, 17:15 Z,
in ,
Harry Bloomfield wrote (paraphrased):
The threaded rod would be in tension, supporting and lifting the
bike. Turn the top (welded-onto-rod) nut and the rod screws into
the lower, captive nut, pulling up the frame.

Harry: Now that you described the design details, if we combine the
torsional shear stress on the threaded rod (due to repeated
torquing) with the tensile stress, and look at fatigue strength of
the threaded rod at the thread root (instead of static strength), my
current calculations in this scenario indicate an M14 x 2.0 mild
steel threaded rod (property class 4.6) can withstand an allowable,
applied tensile load of 2570 N for a long lifespan. An M12 x 1.75
might also work, if well greased, but the M14 gives you extra
margin.

I assume your stainless steel rectangular tubes are perhaps AISI
304L stainless steel, or comparable. Welding these with common mild
steel welding rods isn't recommended. I recommend using AISI 309L
welding rods. And this same welding rod (309L) can be used for
welding stainless steel 304L to mild steel.

David H. Neumann has brought this to us :
Harry: Now that you described the design details, if we combine the
torsional shear stress on the threaded rod (due to repeated
torquing) with the tensile stress, and look at fatigue strength of
the threaded rod at the thread root (instead of static strength), my
current calculations in this scenario indicate an M14 x 2.0 mild
steel threaded rod (property class 4.6) can withstand an allowable,
applied tensile load of 2570 N for a long lifespan. An M12 x 1.75
might also work, if well greased, but the M14 gives you extra
margin

Thanks, but I managed to get hold of a threaded rod of about 20mm OD
complete with nuts. Obviously well over the top for the load, but found
in a scrap yard so quite cheap. The same place had one of those manual
type hydraulic fork lift trucks to dispose of really cheap (£100). Had
I known about it before I started on this it would have saved me a lot
of effort. All it would need is a 'spectacle' frame added to the forks
to lift a bike with ease.

I have made a start now on the base and the vertical post, but I have
had concede defeat on cutting out the sliding part which fits around
the post and onto the 'spectacle' part to actually lift the bike - I
asked a steel fabricator to cut these for me.



--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk