E-3120 Square Root Blade – Service Exchange Spring Tube
Blade Spring Tube Upgrade for Square Root Blades, service exchange OEM
£780 + VAT, Ex Works (EXW)
Part Number: SW-3120-SE-BSTU-SQ (OEM)
- Most economical solution offered usually supplied in sets of 3
- Service Exchange - we will need your old spring tubes which must be in a sound condition for remanufacture
- Re-uses OEM springs - 90 day warranty only on springs
- All new rod end bearing housing with swivel bearing to accommodate any angular misalignments and provide a little 'give' in service to reduce wear
- Phosphor bronze bearing shells - field replaceable by lowering the blade holder off the hub arm
- All new high tensile 28mm dia rod
- Captive rubber washer provides cushioning in rotor overspeed operation
- Spring tube has welded end cap - any failed spring parts are wholly captive
- Shown here with Mk2 blade holder 10 hole flange - 4 hole flange version available
Description
This is a service exchange component designed to be fitted by the customer if desired. Factory fitting is recommended however as several issues may emerge when fitting in the field. First, the OEM square root blade holders are not fabricated to tight tolerances and up to 3mm misalignment is possible between blade pin and pivot blocks. In the factory, the spring tube is assembled into the blade holder with the flange being welded only after all the parts are aligned.
The customer can repeat this process provided they have the facilities to suspend the spring tube and blade holder prior to welding of the flange. Alternatively, the flange can be welded in the factory and a pack of shims supplied for the customer. The customer should also be aware that the screws securing the original spring tube to the blade holder are frequently seized or broken. If this is the case, the screws will have to be drilled out and the hole re-tapped. For these reasons, factory fitting is advised.
Mk1 blade holders use 4 off M8 screws to secure a 4 hole flange in place of the 10 hole flange illustrated above. These fasteners invariably fail which is why EWP moved to the 10 hole version. In this case, we can supply a 6 hole flange plate that uses M10 cap head screws. Note that the customer will be responsible for drilling and tapping the blade holders. Again, factory fitting is advised and will likely be the cheapest option in the long run.
