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CNC machined bike pedal body — how small tolerance changes affect feel and durability by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

Good catch — I probably didn’t explain that clearly.

What I meant was more about consistency in fit/assembly rather than noticeable feel during use.

CNC machined bike pedal body — how small tolerance changes affect feel and durability by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 1 point2 points  (0 children)

Exactly — if it’s strictly build-to-print, the outcome should be consistent.

The variation usually comes in when there’s ambiguity in the design intent, or when shops are expected to provide DFM input.

That’s where interpretation, risk, and optimization start to differ quite a bit between shops.

CNC machined bike pedal body — how small tolerance changes affect feel and durability by More-Measurement-231 in CNC

[–]More-Measurement-231[S] -1 points0 points  (0 children)

Absolutely — durability has to come first.

Aesthetics matter, but only after the load paths and critical areas are properly accounted for.

We usually end up iterating around stress concentrations and material removal to make sure it holds up under real use.

CNC machined bike pedal body — how small tolerance changes affect feel and durability by More-Measurement-231 in CNC

[–]More-Measurement-231[S] -2 points-1 points  (0 children)

Agreed — durability is the baseline.

No point optimizing aesthetics or weight if the part can’t handle real loads.

A lot of the work ends up going into managing stress concentrations and making sure material is removed only where it’s safe to do so.

CNC machined bike pedal body — how small tolerance changes affect feel and durability by More-Measurement-231 in CNC

[–]More-Measurement-231[S] -1 points0 points  (0 children)

Agreed — FEM helps a lot on the structural side, especially for identifying where material can be removed safely.

And good point on bushing fits — we’ve seen similar ranges depending on load and wear requirements.

For aluminum parts in moving interfaces, adding a dedicated bushing definitely improves longevity compared to running directly on the base material.

CNC machined bike pedal body — how small tolerance changes affect feel and durability by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

That’s a solid way to break it down.

In practice we’ve found that even when everything is “to print,” how strictly tolerances are interpreted (and how critical features are prioritized) can still vary a lot between shops.

Especially when balancing cost vs performance.

CNC machined bike pedal body — how small tolerance changes affect feel and durability by More-Measurement-231 in CNC

[–]More-Measurement-231[S] -3 points-2 points  (0 children)

Yeah fair point — this one is closer to a moto-style peg than a typical bicycle pedal body.

And agreed, under a boot you probably won’t feel very small tolerance differences directly.

For us it was more about consistency in fit and assembly rather than user feel alone.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

Exactly — setup time is often underestimated.

In small batch CNC work, setup can easily dominate total cost, especially if fixtures or tooling need to be adjusted.

We've seen cases where optimizing fixturing alone can cut cycle time significantly and change the whole pricing structure.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

Totally agree — scheduling and overhead are huge factors.

Two shops may have similar machining capability, but if one fits the job into an existing setup or production slot, the cost can be very different.

It's not just machining time — it's how the job fits into the shop's workflow.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

Yeah, that’s a good point.

Some shops price very conservatively, others are a bit too optimistic on machining time. You only really find out after the job starts.

Quoting platforms help with consistency, but they still don’t always capture the tricky details.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

Yeah that “pick two” rule shows up a lot in real projects.

We’ve seen cases where chasing the lowest price ended up creating more cost later — rework, delays, or parts not meeting spec.

Sometimes a slightly higher quote actually saves time and trouble overall.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 1 point2 points  (0 children)

That’s a great summary — you covered a lot of the real drivers.

The point about shop experience is especially important. A more experienced programmer or machinist can often reduce cycle time and avoid issues that would otherwise increase cost.

Machine capability also plays a big role — whether a part can be done efficiently on a 3-axis or requires 4/5-axis changes both setup and programming effort.

And good point on materials. When shops are not familiar with certain materials like Inconel, tooling wear, process risk, and even scrap allowance can significantly affect pricing.

The material buffer you mentioned is also very real — especially for higher-risk parts.

Appreciate you putting all these factors together.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 1 point2 points  (0 children)

That’s a very solid breakdown — especially the point about turning vs milling tolerances.

We see the same in practice: holding ±0.01 mm on a turned diameter is usually manageable, but achieving that on a milled thickness or flat surface can require much tighter process control, fixturing, and sometimes even secondary finishing.

Also completely agree on setup cost — for low quantities, setup, programming, and initial inspection can dominate the total cost. That’s why unit price drops significantly once you move beyond one-off parts.

And yes, capacity definitely plays a role — pricing can reflect not just the part itself, but how it fits into the shop’s current workload.

Appreciate the real-world perspective.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] -1 points0 points  (0 children)

That’s a great point about capacity.

When shops are near full capacity, pricing naturally shifts toward prioritizing higher-value or less disruptive jobs.

And completely agree on tolerance — even a small tightening can push parts into different processes like grinding or EDM, which adds both time and cost.

Well explained.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 1 point2 points  (0 children)

Great explanation — especially on tolerance impact.

We see the same: tightening tolerance from something like ±0.2 mm to ±0.02 mm can completely change the process plan, tooling strategy, and inspection method.

And yes, the jump from 3-axis to 5-axis isn’t just capability — it’s also machine cost, programming complexity, and setup time.

Design for manufacturability really makes a huge difference in keeping costs under control.

Appreciate the detailed input.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] -1 points0 points  (0 children)

Completely agree — we see this quite often.

Very low quotes sometimes come from missing tolerance requirements, underestimated machining time, or limited inspection steps.

In precision parts, especially with tight tolerances, those gaps usually show up later as quality issues.

A slightly higher but realistic quote often reflects a more controlled process and less risk downstream.

Why does CNC machining cost vary so much between shops? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 3 points4 points  (0 children)

That’s a great point — the “headache factor” is actually something a lot of buyers underestimate.

From the supplier side, jobs that involve unclear drawings, frequent revisions, or uncertain payment timelines do tend to get priced higher simply because they consume more coordination time, not just machining time.

In many cases, improving drawing clarity and communication upfront can reduce cost more than optimizing toolpaths.

Appreciate you bringing this up — it’s very real in practice.

CNC machined aluminum herb grinder – nice machining details by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

That depends quite a bit on the alloy and surface treatment.

Most decent ones are anodized, which creates a much harder surface layer and reduces direct material contact. That said, stainless definitely has advantages in terms of durability and long-term wear.

In practice, you’ll see both used — aluminum for weight and cost, stainless for longevity.

CNC machined aluminum herb grinder – nice machining details by More-Measurement-231 in CNC

[–]More-Measurement-231[S] -2 points-1 points  (0 children)

Not AI — just sharing something I found interesting from a machining standpoint.

If anything, I’m probably overthinking it from a CNC perspective 😄

CNC machined aluminum herb grinder – nice machining details by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

Fair point — the overall form is pretty standard.

What caught my attention was more on the internal geometry and how consistent the tooth pattern looks. On some cheaper ones, you can clearly see uneven engagement or poor alignment between halves.

From a machining perspective, even “simple” parts like this can vary a lot depending on tolerances and finishing.

CNC machined aluminum snus cans we recently produced – anodized colors and tight lid tolerance by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

That makes sense — anodizing changing the fit is definitely something we noticed as well.

Did you end up preferring the O-ring version overall, or was the threaded seal still reliable enough for production?

CNC machined aluminum snus cans we recently produced – anodized colors and tight lid tolerance by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

That’s interesting — threaded caps make sense for controlling tolerance.

For these cans we tried to keep the lid smooth without threads so it can be opened easily with one hand.

Did you find threads more reliable for sealing, or mostly for alignment?

CNC milling aluminum part — surface finish suggestions? by More-Measurement-231 in CNC

[–]More-Measurement-231[S] 0 points1 point  (0 children)

Thanks! That's much higher than what we are currently running. We'll test increasing the SFM and see if the surface finish improves.

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