Valley Forge Robotics
Valley Forge
Robotics
Request → Tools → Toolpath
Non-indexable only

Valley Forge Tooling

Describe what you want to machine in plain English. Get instructions, purchasing links, and visuals you can sanity-check.

Scope: non-indexable tools only (solid drills, taps, end mills, chamfer tools, cutting fluids).

Your request
Priority
Safe is slower but more forgiving.
Current plan source: Built-in
Threaded blind hole: 1.00" deep, 1/2-13 UNC in 316 Stainless
Turns a vague request (“make a threaded hole”) into a concrete recipe: drill the correct size, break the edge, then tap with the right style and lubrication.
Safety notes
  • Always confirm parameters against your machine rigidity, tool manufacturer guidance, and shop standards.
  • If you’re new: start conservative, watch chip shape, and adjust gradually.

Feeds & speeds

Lock what you care about; everything else solves around it.
Machine limits
Operation controls
Key math
  • RPM = (SFPM × 3.82) ÷ Diameter(in)
  • Drill feed (IPM) = RPM × IPR
  • Tap feed (IPM) = Tap RPM ÷ TPI

Key parameters

sanity-check numbers
Tap drill
0.4219in
Starter hole size for the tap.
Drill depth
1.1in
Includes a little extra depth for drill point.
Chamfer tool
0.75" × 90°
Example tool spec for breaking the edge (countersink/chamfer tool).
Drill SFPM
25SFM
Surface speed at the cutting edge (often treated as a speed limit).
Drill RPM
226RPM
Derived from SFM and drill diameter.
Drill IPR
0.003in/rev
Feed per revolution.
Drill feed
0.68IPM
Feed = RPM × IPR.
Tap TPI
13TPI
Threads per inch (drives tapping feed).
Tap RPM
80RPM
User-adjustable; feed must correlate.
Tap feed
6.154IPM
Feed = RPM ÷ TPI.

Depth over time

Z plotted across program progress
max Z: 0.100min Z: -1.100
This is a quick sanity-check visualization. If you see an unexpected deep plunge, investigate before running the program.

Toolpath stats

quick geometry checks
Total path length
5.00 in
Moves (segments)
7
XY bounds
X: 0.000 → 0.000
Y: 0.000 → 0.000
Z range
max: 0.100
min: -1.100

Instructions

beginner-friendly steps
1) Drill the tap hole
Tool: 27/64" (0.4219") twist drill (material: Cobalt)
What: Drill a 0.4219" hole to ~1.1" deep (includes a little extra depth).
Why: A tap can’t create a hole — it needs a correctly-sized starter hole. Too small = broken tap. Too big = weak threads.
Watch-outs
  • 316 stainless work-hardens. Don’t let the drill rub. If chips stop, back out, clear chips, and re-enter cutting.
2) Chamfer the hole edge
Tool: 0.75" × 90° countersink / chamfer tool
What: Lightly break the top edge of the hole using a countersink/chamfer tool (example: 0.75" × 90°).
Why: This helps the tap start straight, reduces burrs, and lowers the chance of chipping the tap on entry.
Watch-outs
  • Too much chamfer reduces thread engagement at the top. Keep it small.
3) Tap the threads
Tool: 1/2-13 tap (spiral flute recommended for blind holes) + tapping fluid
What: Use a spiral-flute tap (pulls chips up) to tap to depth.
Why: Tapping is a common failure point. The right tap style + lubrication dramatically reduces the odds of breaking the tap.
Watch-outs
  • If torque spikes or the tap feels like it’s binding, stop and clear chips. Don’t force it.
  • Use proper tapping fluid. Stainless + dry tapping is a common failure mode.

Tool list

each step uses a different tool
T2
27/64" Cobalt Drill (M42) — Better for Stainless
  • Diameter: 0.4219 in
  • Tool material: Cobalt
T3
3/4" 90° Countersink / Chamfer Tool (Deburr + Tap Start)
  • Countersink: 0.75 in major dia
  • Included angle: 90°
T4
1/2-13 Spiral Flute Tap (Blind Holes)
  • Thread: 1/2-13 UNC
  • TPI: 13
  • Pitch: 0.076923 in/rev
  • Workpiece: 316 Stainless
FLUID
Tap Magic (Cutting Fluid) — for Tapping Stainless
  • Use for tapping (especially stainless).
This is the missing “context” that makes the recipe, procurement, and any code output make sense.
Tap calculations
Tap math is simple but easy to mess up: Feed = RPM × pitch. Pick what you want to solve for, then adjust the other inputs.
Solve for
Default is Feed, so when you change RPM the feed updates automatically.
Converted (for “machines in standard”)
Pitch (in/rev)
Feed (mm/min)
Math (4 decimals)
pitch_in = pitch_mm ÷ 25.4 = ÷ 25.4 = in/rev
feed_ipm = RPM × pitch_in = × = IPM
(equivalently) TPI = 1 ÷ pitch_in =
Example: M3x0.5 → pitch is 0.5 mm. We convert that to ~0.019685 in/rev (~50.8 TPI) so you can sanity-check a tapping feed in IPM.

Procurement

live product options + outbound links
Drill • Cleveland
27/64" Cobalt Drill (M42) — Better for Stainless
Cobalt is a safer default for stainless.
tool material: Cobaltgood for: 316 Stainless, Stainless Steel (generic)…
Search term
Suppliers
Open supplier search
SupplierLink
MSCSearch “Cleveland 27/64" Cobalt Drill (M42) — Better for Stainless”
GraingerSearch “Cleveland 27/64" Cobalt Drill (M42) — Better for Stainless”
KBCSearch “Cleveland 27/64" Cobalt Drill (M42) — Better for Stainless”
McMasterSearch “Cleveland 27/64" Cobalt Drill (M42) — Better for Stainless”
Chamfer Tool • Generic
3/4" 90° Countersink / Chamfer Tool (Deburr + Tap Start)
A small chamfer helps the tap start straight and reduces burrs.
Search term
Suppliers
Open supplier search
SupplierLink
MSCSearch “Generic 3/4" 90° Countersink / Chamfer Tool (Deburr + Tap Start)”
GraingerSearch “Generic 3/4" 90° Countersink / Chamfer Tool (Deburr + Tap Start)”
KBCSearch “Generic 3/4" 90° Countersink / Chamfer Tool (Deburr + Tap Start)”
McMasterSearch “Generic 3/4" 90° Countersink / Chamfer Tool (Deburr + Tap Start)”
Tap • OSG
1/2-13 Spiral Flute Tap (Blind Holes)
Spiral-flute taps are a strong default for blind holes (chips come back out).
Search term
Suppliers
Open supplier search
SupplierLink
MSCSearch “OSG 1/2-13 Spiral Flute Tap (Blind Holes)”
GraingerSearch “OSG 1/2-13 Spiral Flute Tap (Blind Holes)”
KBCSearch “OSG 1/2-13 Spiral Flute Tap (Blind Holes)”
McMasterSearch “OSG 1/2-13 Spiral Flute Tap (Blind Holes)”
Cutting Fluid • Tap Magic
Tap Magic (Cutting Fluid) — for Tapping Stainless
Strongly recommended for stainless tapping.
Search term
Suppliers
Open supplier search
SupplierLink
MSCSearch “Tap Magic Tap Magic (Cutting Fluid) — for Tapping Stainless”
GraingerSearch “Tap Magic Tap Magic (Cutting Fluid) — for Tapping Stainless”
KBCSearch “Tap Magic Tap Magic (Cutting Fluid) — for Tapping Stainless”
McMasterSearch “Tap Magic Tap Magic (Cutting Fluid) — for Tapping Stainless”
Alternatives
Drill • Generic
27/64" HSS Jobber Drill (Tap Drill for 1/2-13)
Budget option. Slower. If stainless is giving you trouble, move up to cobalt.
tool material: HSSgood for: 1018 Steel, Carbon Steel (generic)…
Search term
Suppliers
Open supplier search
SupplierLink
MSCSearch “Generic 27/64" HSS Jobber Drill (Tap Drill for 1/2-13)”
GraingerSearch “Generic 27/64" HSS Jobber Drill (Tap Drill for 1/2-13)”
KBCSearch “Generic 27/64" HSS Jobber Drill (Tap Drill for 1/2-13)”
McMasterSearch “Generic 27/64" HSS Jobber Drill (Tap Drill for 1/2-13)”
Tip: Start with the “primary” picks, then compare live options across suppliers if lead time or pricing matters.
Advanced: program + backplot(optional)
Backplot g-code

Backplotter

Program
Supports G0/G1/G2/G3 + expands G81/G83/G84 (best-effort)
Visualization
Playback
0
Speed
1×
Position
X0.0000 Y0.0000 Z0.0000
Modes
Inch (G20)Absolute (G90)G17G54?Tool T—
Spindle: OFF
Feed: — IPM
Line 5
Tip: if a “real” program looks like a dot/line in XY, switch to the Z view — drilling/tapping is mostly vertical motion.

Program

Controller: Haas (Fanuc-style)
“Machine” is a controller-style skeleton. “Plot” expands canned cycles so the backplotter matches reality.
Tip: if your machine code uses G81/G83/G84, switch to Plot for visualization.
Safety note: Verify tooling and parameters against manufacturer data and shop standards.