Project costs

What it costs to build the complete motorized sting balance: the machined and 3D-printed hardware, the bought mechanical parts, and the electronics. Machined and printed parts use real quotes from JLCCNC and JLC3DP; the other lines are supplier estimates.

Cost breakdown

Not included: import duty, if it is charged as a separate tax line on the China orders (see from the quote to the final order); shipping for the JLC3DP pod order; labour; the test models; spare parts. If students machine the simpler plates and brackets in a university shop, the machined-parts line drops.

Hardware details

The custom metal parts are quoted by JLCCNC (36 STEP files uploaded as a first pass, without drawings) and the printed pod by JLC3DP. The sections below show the quotes, what is still to add before ordering, and every part.

The JLCCNC quote (2026-10-03)

The 36 STEP files were uploaded as a first pass, without drawings, so every line was priced with JLCCNC's defaults (all lines: Aluminum 6061, bead blast, ISO 2768 medium, standard (no drawing uploaded)). 34 lines were priced instantly; the base tube and the pitch rack are quoted by JLCCNC staff, which is normal for those shapes.

Economy build time (11 days) is about 8 % cheaper than Standard, and two coupons ($200 + $125) were offered on the order.

Separate order: the 3D-printed reference pod (WT-6C-004) is quoted by JLC3DP at $112.96 in PC-ABS. It has to be printed, not machined: its 0.060 in pressure channels run inside the wall. When it arrives, clear the channels and check every tap with the blow-through test on the drawing. Shipping for this order is not included here (it may combine with the JLCCNC parcel if ordered together).

From the quote to the final order

A few finishing steps turn the first-pass quote into exactly the parts on the drawings: the right materials for the three precision parts, the drawing tolerances, the two staff quotes, and anodizing. Expected effect on the price:

The machined-parts line in the cost breakdown is this total less the pod. Import duty: JLCCNC ships DDP and handles any US import tax at checkout. If it shows as a separate tax line rather than inside the shipping price, it adds about $1,990-3,285 at current rates (tariffs change often); a university purchasing office can advise on duty for lab equipment.

Part by part

JLCCNC quote: the real price for the line (quantity included, first-pass settings). China est.: the estimate for the part as drawn, calibrated to the quote. US: US marketplace (Xometry / Protolabs Network, shipping included). Shop: local shop at $65-105/h. Next step: what to set when ordering.

Ordering checklist

1. Materials: balance 7075-T651; sting and spindle 42CrMo (the standard Chinese grade equal to 4140); everything else 6061-T6.
2. Drawings: attach the PDF (Drawings page; cad/drawings/WT-6C-xxx.pdf in the project) and choose "per drawing" tolerances for the balance, sting, spindle, housing, caps, puck, sleeve, cheeks, racks, rails and drive bracket.
3. Drawing-only features: rack teeth (gear data tables) and the yaw rail V-edges.
4. Finish: clear anodize II; hard anodize III on the yaw rails; none on the balance; black oxide on the steel parts.
5. Quantities: head plate, cheek, cross spacer, drag and thrust uprights, axle and 2 in pulley x2; wheel spacers x4 each (the thrust pulley is the same part as the 2 in pulley).
6. Yaw carriage (5xx): order as a second batch once the bay floor is measured; everything else can be built and calibrated first.
7. Build time and coupons: economy saves ~8 % if 11 days is fine; apply the coupons at checkout.

About the two staff-quoted parts

• WT-6C-307 base tube: a 31 in length of 3 x 1.5 x 0.125 in rectangular tube. The instant quoter prices parts milled from a solid block, so a person prices it from bought tube. Easy alternative: buy the tube cut to length locally and drill the 18 holes in a school shop.
• WT-6C-402 pitch rack: its gear teeth are cut by wire EDM and two holes go into its edge, so it is priced from the drawing. Attach WT-6C-402 and ask for EDM teeth.

Electronics details

The electronics are priced from the itemized parts list on the Electronics & control page ($1,571 at typical 2026 supplier prices); the breakdown shows ±10 %. Motors and gearboxes are in the bought mechanical parts. By group:

A custom strain-gauge readout PCB is deferred; the first build uses off-the-shelf modules (see the Electronics page).

Supplier options (machined parts)

For reference, estimated totals for the parts as drawn: local shop at shop rates $9,124-14,827; US marketplace $12,741-20,344; SendCutSend for its 11 parts $963-1,876.

How the estimates were made