How we design and assembly

Component application: Logimarkt offers various solutions to a brief, but design factors such as ease of adjustability can be build in, using design for assembly techniques, or the ability to add to the design post-build for continuous improvement. These factors may be a simple case of asking which orientation is the joint going to be used to gain the maximum benefit?

For example, a three-way tube assembly may be achieved using a joint assembly in different orientations to give benefits for different applications.

Pipes dimensions – nominal dimensions are :

1. 1. Pipe outer diameter 28 mm
   2. Joint inner diameter 28 mm
   3. Joint outer diameter 33 mm

• Length of pipe between two joints = outer dimension – 100 mm
• Most pipe lenghts are terminated with a joint „Head/Tail”, and so their lengths are calculated as joint centres minus 70 mm (2x35mm).
• Although the sysstem does allow some small flexibility on pipe length, this should be kept to a minimum (-3mm).

Roller track gradient ideal is 5-6%, depending on load (heavier boxes roll faster). This should be adjusted, depending on the application

Ergonomics:

Getting the ergonomics right for the application concerned is not only a matter of comfort, but also of safety, efficiency and satisfaction of the user. Working heights, picking heights, bending and reaching limits, etc. are mostly known by the company’s Health and safety policies.

Ergonomic picking options for racks:

• standard end stops
• sections staggered at rear
• containers angled forward

Ergonomy for workbenches:

• recommended projection of work-top: 20mm laterally and at rear, 40mm at front
• foot room: place frontal transverse pipe back 250mm
• 3 pairs of feet are recommended for lengths more than 1600mm

Design options: there are usually several alternatives in the way that the workstation, trolley or rack can be built. These are a few options:

Determine the requirements:

• Function: workstation, trolley, gravity kanban rack, etc.
• Dimensions: it must be said which one are they, inner or outer dimensions,because these are otfen confused
• Load: dimensions, weight, whether dynamic or static, shape and any particulars such as a special surface, sharp edges, etc
• Further special characteristics: ESD, moveable, chemical resistance, etc.

Planning – first sketch: An initial sketch from your team is useful at the first point, concentrating on the horizontal spans and vertical lengths within standard guidelines for pipes and roller tracks. It is worth noting that good design practice avoids cantilever loads where practical, as this may unbalance or topple the rack.

Define required unit loads/weights : the next step is to look at how much load will be applied, first the weight per level and then combine this for multiple levels to define a complete unit loading. Heavy loaded racks that are more than 1000 kg in unit load, are most likely too much and alternative solutions may be more suitable.

When the rack has more than two upright supports, the inner ones will need to carry twice as much load as the outer supports.

Height to width ratio: to ensure the structure’s stability, the height to width ratio should not be exceeded the ratios as stated bellow, unless it is a permanently floor fixed structure. Units with castors should on certain cases use a lower ratio, because they are movable and can hit an obstruction on the floor and topple. Each application needs individual consideration.

• Shelving : recommended a maximum 1:5 ratio between the feet of the shortest base dimension (A) and the height of the topmost shelf (B) – see figure H.
• Trolleys: recommended a range of between 1:3 to a maximum of 1:5 ratio between the wheel axle distance (A) and the height of the topmost shelf (B) – see figure I.

Basic guidance chart (depending also on the load):

Use of crossbars: crossbars are recommended for spans in excess of 1000 mm.

Use of diagonals: there is a risk of twisting and instability if no diagonal bars are used; always to be used with dynamic loads as a matter of course. Diagonals must be always oriented in flow direction (roller track).

Possible mounting versions:

Assembly of basic frame – recommended:

• all upper pipes must be always unbroken in length
• all lower pipes must be separated at feet
• all load-bearing pipes can be carried through, right down to the floor (wheel/foot)

Length of roller tracks: how it’s calculated, for example:

Recommendation for assembly:

• If a roller is too close to a saw cut, it needs to be removed before cutting, and reinserted if possible
• Very important: the roller must not protrude over the edge
• All load-bearing pipes must be carried through, right down to the floor (wheel/foot)
• Roller tracks must be trimmed at right angles
• Length of a roller track without vertical suport must be up to 1000mm
• Clearance width between lateral guides = size of container/box + 10mm (5mm for each side)
• Rollers should run on the edge of the container
• If the containers have sensitive surface or components, rubber rollers are recommended
• Gradient has a reference value approx. 6% (60mm over 1000mm), but the slope depends on:
  • The weight of the containers/boxes
  • The condition of the containers/boxes
  • The type of rollers
  • In case of cardboard packaging, it requires more
  • In case of lighter containers, if those standing on the roller track do not run of their own accord, gradient must be increased

Joints assembly

All joints must be neatly connected, so that the joints sleeves are parallel, and correctly dovetailed. Ensure that the tubes are fully inserted into the joints before tightening. For joints in which a tube terminates, there should be a a 30mm of joint sleeving the tube.

Joints have their tolerance, so that the pipe must be fully inserted into joints, as in the pictures bellow.

First, you must position the joint components in place over a tube. Insert the “T” nuts into the recesses on the least accessible side of the joint assembly, with the shoulder of the nut sticking through the hole and the flag edges captivated by the recess sides.

The shoulder of the nut will improve the interface between the nut and bolt, allowing the threads to engage inside of the joint assembly.

Inserts and end caps: threaded inserts and inner end caps are push fit and hammered into the opened tube ends

Drawer sliders: determine how much a drawer has to open and where is the safety point, so that there is no danger for the entire structure to flip over.

• We take into consideration handling and capacity load for each drawer.
• Each drawer slide is categorised into the load rating it can take, and care must be taken to ensure the right drawer slide is chosen, for the application in question
• There are 3 loading limits, rated at 0.5 m distance between drawers:
  • Light duty drawers, for maximum 50 kg capacity load;
  • Medium duty drawers, from 51 to 99 kg capacity load;
  • Heavy duty sliders, for more then 100 kg capacity load.
• The heaviest ones must be placed in the bottom part of the structure, and the light ones on the top.