Machine frames, platforms, supports and lifting structures all need to be stiff enough to work and strong enough to be safe. We size members by calculation and detail them so they can be fabricated and welded by a normal workshop.
Where it helps, FEA is used to check deflection and stress, with hand calculations as the cross-check.
What We Do
Steel structure design
Section selection, bracing and connection design for the real load cases.
Machine frame design
Stiffness targets met with the least material and welding.
FEA-backed calculations
Linear static checks for stress and deflection, cross-checked by hand.
Weld and fabrication drawings
Weld symbols, sequence notes and tolerances the fabricator can follow.
Lifting and handling structures
Cranes, hoists and spreaders sized with proper safety factors.
Retrofit and strengthening
Existing structures assessed and reinforced for new loads.
Typical Deliverables
- Structural calculation report
- 3D structure model
- Fabrication and weld drawings
- Anchor and interface details
- Bill of materials with cut list
- Inspection points for fabrication
Structures designed for stiffness, not just strength
A machine frame that is strong enough can still be the reason a machine fails to hold tolerance. Deflection under cutting force, vibration from a fast axis or twist in a long gantry all show up as poor accuracy, noisy operation and early wear. LTM sizes machine frames, bases and steel structures for stiffness first, then confirms strength, buckling and weld capacity, and documents every check in a calculation report.
Structures we design
- Machine frames and bases: welded steel bases for SPMs, machine tools and automation cells.
- Gantries and overhead structures: linear axis gantries, robot gantries and camera or sensor bridges.
- Platforms, walkways and supports: operator platforms, equipment supports, pipe and cable racks.
- Lifting structures: lifting beams, spreader beams, jib structures and knuckle boom crane structures.
- Retrofit and strengthening: checks of existing structures for new loads, with reinforcement details.
Choosing the right deflection limit
The most important structural decision on a machine is often the deflection limit, because it controls the section size more than stress does. General platforms and supports work well at L/250 to L/360. Machine guards and enclosures are usually fine at L/500. Machine bases, gantries carrying linear axes and frames that position tooling need L/1000 or stiffer, and precision measuring or machining structures can need L/2000 or better.
Setting the limit too loose gives a light frame that vibrates and loses accuracy; setting it too tight wastes steel and adds weight to moving parts. We agree the limit with you at the start, based on what the structure carries and the accuracy it must hold, and state it clearly in the calculation report so every later change can be checked against it.
How each structure is checked
Members are first sized by hand calculation: bending and shear stress, deflection against a limit that suits the function (from L/250 for general structures to L/1000 or stiffer for machine bases), column buckling, weld throat stress and bolted connection capacity. Where geometry or load paths are complex, a linear static FEA model is built and compared against the hand results so errors in either method are caught. Standard sections from IS 808, IS 4923 and EN 10219 are preferred so material is easy to buy and fabricate.
Fabrication-ready output
Drawings are made for the workshop that will build them: clear weld symbols, cut lists with standard lengths, datum features for machining after welding, and inspection points for the fabricator. Where a frame needs stress relieving or machining of mounting faces, that is specified on the drawing, not left to assumption.
Deliverables and pricing
You receive a structural calculation report, 3D structure model, fabrication and weld drawings, anchor and interface details, and a bill of materials with cut list. A structural frame check starts from ₹15,000 with delivery in about four working days.
Run a quick first check yourself with the free beam deflection, bending stress and steel weight calculators.
Frequently Asked Questions
Do you use FEA for every structure?
No. Most frames are sized faster and more transparently by hand calculation. FEA is used where geometry, load paths or stiffness requirements make hand methods unreliable, and the two are always cross-checked.
Which steel sections do you design with?
Standard rolled and hollow sections to IS 808, IS 2062, IS 4923 and EN 10219, chosen for availability in your market so fabrication is not delayed.
Can you certify a structure for lifting?
LTM provides design calculations and drawings with stated safety factors. Proof load testing and statutory certification are carried out by the competent person or authority in your region.
Can you check an existing frame that is vibrating or deflecting?
Yes. Send photos, measurements and the load case, and we will identify the weak load path and design stiffening that can be welded on site.
Do you design structures for vibration?
Yes. Where a structure carries fast axes, rotating equipment or impact loads, natural frequencies are checked and kept away from operating frequencies.
How an Engagement Works
Brief
You share the function, loads, space, cycle time and any drawings you already have.
Concept
We propose a concept with a layout sketch and the key calculations, so you can approve direction early.
Detail design
3D model, calculations, GD&T drawings and BOM, reviewed with you at agreed checkpoints.
Release and support
Native files and PDFs handed over, with support during fabrication and assembly.
Have a project in mind?
Send a short brief with sketches or specifications. You get a clear scope and a fixed quote, usually within one business day.