Transcript Types of dimensioning - NW 14-19

Dimensiynu
Dimensioning
……………….BS 8888
Dimensiynu Cyfochrog / Parallel Dimensioning
Nifer o dimensiynau yn
cychwyn o un llinell tafliad
Several dimensions
originating from one
projection line
……………….BS 8888
Dimensiynu Cadwyn / Chain Dimensioning
Dim ond ei ddefnyddio
os nad yw’r darn yn cael
ei effeithio gan
goddefiant cynyddol
Only to be used if the
object is not affected by
the accumulation of
tolerances
……………….BS 8888
Dimensiynu Cyfuno / Combined Dimensioning
Dimensiynu sy’n cyfuno
cyfochrog a chadwyn
Dimensioning that combines
parallel and chain
……………….BS 8888
Dimensiynu Cylchoedd / Dimensioning Circles
A) Dimensiynu tu fewn i’r cylch / dimensioning internally
B) Dimensiynu tu allan i’r cylch / dimensioning externally
C) + D) Dimensiynu tu allan os yw’r cylch rhy fychan /
External dimensioning if the circle is too small
……………….BS 8888
Dimensiynu Radiws / Dimensioning Radii
A) Dimensiynu gyda canol y radiws ar y gwaith / dimensioning with the centre
of the radius on the work
B) Dimensiynu radiws heb angen lleoliad canol y radiws / dimensioning a
radius that doesn’t require the location of the radius centre
C) Dimensiynu radiws sfferaidd / Spherical radius dimesioning
……………….BS 8888
Dimensiynu Tyllau / Dimensioning Holes
……………….BS 8888
Dylunio Edau / Drawing Threads
A) Pan yn dylnuio edau or pen,
maer llinell adau yn cael ei
ddangos gan cylch sydd wedi
torri
A) When drawing threads end on,
the threaded line is shown by a
broken circle
B) Yn aml fydd edau yn cael ei
ddangos tu fewn i rhan gan llinell
wedi torri
B) Frequently a thread will be
shown inside a part by a broken
line
C) Dyma sut i ddylunio edau ar
ddyluniad trychiadol
c) This is how to show a thread
on a sectional drawing
……………….BS 8888
Dangos GARWEDD ar luniadau Peirianneg - Showing ROUGHNESS on Drawings
Mae’r gwybodaeth isod wedi ei tynnu or British Standards 1302
ar gyfer labelu diagramau er mwyn ddisgrifio garwedd
BS EN ISO 1302:2002 Geometrical
product specifications (GPS).
Indication of surface texture in technical
product documentation
The information below is taken from the British Standards 1302
for labelling diagrams to describe the surface finish:
Esiampl o ddiagram yn dangos y symbol ar gorffeniad
Example showing the symbol being used on an engineering
drawing
Esiamplau gwerthoedd Ra gwahanol / Rules of Thumb for surface finish in Ra values
Turnio garw – medru gweld y marciau / Rough turned with visible toolmarks....Ra = 12.5μm (micro.m)
Peiriannu llyfn / Smooth machined surface....Ra = 3.2 μm (micro.m)
Greindio / Surface Grinding… Ra = 1.6 μm(micro.m)
Gwynebau Lapio Llyfn / Fine lapped surfaces.... Ra= 0.025 μm (micro.m)
……………….BS 8888