Stepped holes callout
Stepped holes callout
(OP)
Hi,
In attached print, how do you like the stepped and chamfered holes callout? I'm trying to come up with a callout simple and clear. Do you think the the callouts shown in first sheet is clear, or I have to do it like the second sheet shows?
In attached print, how do you like the stepped and chamfered holes callout? I'm trying to come up with a callout simple and clear. Do you think the the callouts shown in first sheet is clear, or I have to do it like the second sheet shows?





RE: Stepped holes callout
If Y14.5 then c'sink holes should be dimensioned per sheet 1 (included angle)
If no c'sink holes (there are chamfered holes) probably you want them with length x angle or length x length.
Sheet 2: too busy IMHO
RE: Stepped holes callout
Regarding dimensioning/tolerancing of the holes either approach would be acceptable, but I personally prefer the approach used on sht 1. However there are a few specific issues with what you show on both sheets. First, I agree with greenimi's comment regarding c'sinks vs chamfers. If all you require is a corner break at the hole edge then call it out as a chamfer. Also, the way your positional tolerance block is located in the hole callout the tolerance applies equally to both the hole and the c'sinks. If you only intend for the positional tolerance to apply to the hole, then the hole dimension should be listed first with the tolerance block immediately below it. If you require a looser positional tolerance for the c'sink features you can add a separate tolerance block just below each of those callouts. You also should add a prefix (such as 4X) describing the number of locations the callout applies if there is more than one. Lastly, since the hole location dimensions on sht 2 are shown as basic you need to add a positional tolerance block somewhere on the drawing for the associated features.
RE: Stepped holes callout
Tunalover
RE: Stepped holes callout
RE: Stepped holes callout
I assume your drawing may be "intentionally incomplete", but if it really is busy, create separate section for your elaborate hole and dimension it there. It will make it easier to interpret, and (which is often ignored) easier to make future revisions.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Stepped holes callout
________________________________
Ryan M
Quality Engineer
3d Printer Hobbyist
RE: Stepped holes callout
_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5
RE: Stepped holes callout
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Stepped holes callout
Tunalover
RE: Stepped holes callout
Specifically, I'd check out Fig 1-38, page 17, for a start. Notice that there is a reason for the order of callout which is a general "order of operations". While the actual order the part is manufactured may differ, and the callout in no way binds anyones hands on which order to install those features, it makes for a good "rule of thumb" so it's easily read. You start with the smallest diameter and work your way to the largest, so to speak.
Sometimes, such in the case of some spotfaces, it is actually cut /opposite/ but there should be some consistency, at least, and not a completely chaotic manner of writing simply because exceptions exist, but I digress.
_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5
RE: Stepped holes callout
The figures show alternate ways to show the holes. The left options show how to do it with one section view. The right options show how to do it with two views (plan and section). My preference is to do it with one section view.
I agree that the order of the features optimally are in the order that they are performed, but any order is technically OK since the drawing is generally an end-item document without processes and the orders they are applied.
Tunalover
RE: Stepped holes callout
_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5
RE: Stepped holes callout
I revised the print based on the first sheet:
1. a separated detailed view showing the most complicated hole.
2. call out those angled features as chamfers. BTW, what exactly is the difference between a chamfer and c'sink? I only have a feeling that c'sink is only for components like flat head screws.
3. in the stepped hole callout, through hole goes first, then larger hole.
4. about the SEP REQT, a rule of thumb here is when the features mate with different parts, SEP REQT is attached.
5. I guess the callout for number of places of same feature is never agreed by companies. I heard different stories. Here I show the number applied to the view, not to the whole part.
Any further comments?
RE: Stepped holes callout
However, what is not needed on this print is datum feature references B(M) and C(M) in profile callout applied to two planar surfaces lying at basic distance 20 from datum plane A, and in consequence SEP REQT beneath that feature control frame.
RE: Stepped holes callout
Two hole patterns are functionally unrelated to each other and functionally unrelated to the central hole so only two of the FCFs need the SEP REQT note. It would be understood that the single hole is a SEP REQT and the note is unnecessary.
I do agree that the profile of a surface tolerance should have no reference to datum features B and C.
Tunalover
RE: Stepped holes callout
Your suggestion (with 2 not 3 SEP REQT notes) will just mean that the callouts applied to both patterns have to be met as separate requirements. In my opinion it will not provide clear instructions whether the 3rd callout is to be checked as another sep reqt or as a sim reqt with one of the callouts applied to the patterns.
Addition of 3rd SEP REQT note eliminates potential confusion once and for all.
RE: Stepped holes callout
The SEP REQT vs. SIM REQT is annoying sometimes when you have many patterns on it. A example, if a part has pattern A and B functionally related to each other, pattern C and D related to each other, pattern E and F related to each other. But these 3 groups are not related among each other. How are you gonna play with the SEP REQT notes?
RE: Stepped holes callout
If that does not look good to you, you can always use a text note to clarify design intent.