What the part has to do
- Grip a carbon or aluminium tube that runs under nominal and out of round.
- Carry motor thrust and landing loads into the structure without slipping.
- Survive a galvanic joint between aluminium and carbon, usually while wet.
- Release when a technician needs to change an arm in the field.
Material and finish
7075-T6 for most clamps, because the ears take bending every time the clamp is torqued. 6061-T6 where the clamp is lightly loaded or has to be welded. Titanium Grade 5 where the joint is permanently wet and weight matters.
Hard anodise type III as standard on anything that flies in weather, with the bore masked or machined after coating. Type II for indoor and cinema aircraft.
The features that decide it
Tolerance these. Let everything else on the drawing run to the general tolerance, because it costs money and changes nothing.
Bore diameter and roundness
Cut before the slot is separated, so the bore is round and concentric rather than machined into a shape that closes crooked.
Slot closure
The gap has to be larger than the closure needed for your smallest tube, or the clamp faces meet before the tube is gripped.
Clamp width and edge break
Spreads the grip across the composite instead of concentrating it in a band that crushes the wall.
Screw boss thread engagement
Thin ears strip if the thread is short. Boss or insert, decided on the drawing.
What we hold
| Feature | Held |
|---|---|
| Bore, before separation | H7 or ±0.02 mm |
| Bore, after separation | Measured and reported, both numbers |
| Slot width | ±0.1 mm |
| Everything else | General tolerance |
Normal production figures for this shop, not a best case. Full tolerance reference.
What we need to quote it
- Measured outside diameter of twenty of your actual tubes, in two planes
- Tube supplier, because the spread differs between them
- Screw size, count and assembly torque
- Whether there is an insulating sleeve, and its thickness
- Finish, and whether the bore is masked
Send what you have. A STEP file and a quantity are enough to start, and the rest sharpens the number.
Read before you draw it
Tools for this part
Run your part through them and send the answers with the model. It makes the quote sharper and the questions fewer.
Questions about arm and boom clamps
Can you match a clamp to a tube I already buy?
Yes, and it is the only way to get the fit right. Send measurements of twenty tubes from your supplier, in two planes at both ends and the middle. We dimension the bore from that spread, not from the nominal diameter.
Do you machine the slot or saw it?
The bore is machined while the clamp is still solid and the slot is cut afterwards, because a bore cut into an already split clamp is not round once it closes. The first article reports the bore before and after separation.
Quote this part
Send the model and the quantity. Price, lead time and any question that would cost you money if we guessed come back within 24 business hours, EXW, in USD.
Need the full form with tolerances, finish and documents? Open the RFQ page.
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Open