[Halld-tracking-hw] CDC Drawings

[Curtis A. Meyer]

10:00am is good  -- Curtis
Tim Whitlatch wrote:
> How about 10am?
>
> Curtis A. Meyer wrote:
>> Hi Tim -
>>  
>>       can we set up a meeting tomorrow morning at 11:00am to go
>> over all the drawings. We have a few questions that I will type in
>> below, and then a number of questions on what certain holes are
>> for that we can discuss.
>>
>> FeedThru/Donut:
>>
>>    1)  The groove for the glue has been slightly modified. This looks to
>>          be a good design as it avoids the chance of breaking a drill 
>> bit. We
>>          are however worried that the sharp edge will catch on 
>> insertion. Can
>>          we put a champfer on the sharp edge on the grooves on the 
>> donuts
>>          and the inserts?
>>
>>     2)  The vent hole on the donuts and inserts was increased in size 
>> to 0.035.
>>           We originally had it smaller to aid in construction so that 
>> it is obvious
>>            which hole the syringe goes into. They are a too close in 
>> size now to
>>             be able to do that. If it was increased for a 
>> manufacturing reason, then
>>             perhaps we should just make both holes the same size. 
>> Otherwise, we
>>             should shrink the vent back down.
>>
>>
>> End Plates:
>>
>>      1) One endplate is still labeled as 6mm carbon fiber. This needs 
>> to be fixed.
>>
>>      2) There are several places where 12/24 screws are used. This is 
>> a very odd
>>           size and difficult to get parts for. This should be changed 
>> to a standard
>>           size.
>>
>>      3) The grooves that are used to hold the shells have widths of 
>> 0.050 and 0.100
>>          inches. Do you have a suggestion for what we should use in 
>> these. Basically,
>>          we want to discuss the size of these.
>>
>>      4) The upstream endplate has 1 mil tolerances on the survey ball 
>> holes and the
>>           support rods. The down stream has 2mil tolerances. Why the 
>> difference?
>>
>>      5) The holes to attach the bearing blocks seemed to us to be 
>> very odd sizes. Perhaps
>>           the match a known unit, but seeing them as drawn, they 
>> seemed  odd. One is
>>           15-thou over a 1/4 and the other is 0.188 inch.
>>
>>      6) It does not appear to us that there are marks on the 
>> endplates to indicate the
>>           first hole in each layer. There is a call-out to the 
>> manufacturer as to which they
>>           are, but it is not obvious that they are marked on the plates.
>>
>>      7)  There is probably a good reason for this, but we noted that 
>> the holes for support
>>            standoffs and gas at the outer diameter are placed at four 
>> different radii. The
>>            numerical values for these seem to be random numbers. The 
>> question is can these
>>            be at round "english" numbers.
>>
>>      8)   We are not sure what a number of the holes are, but the 
>> twelve  5/16" threaded holes
>>             at 23.15" radius confused us. What are they?
>>
>>   Cheers -- Curtis,
>>
>>   
>


-- 
Prof. Curtis A. Meyer		Department of Physics
Phone:	(412) 268-2745		Carnegie Mellon University
Fax:	(412) 681-0648		Pittsburgh PA 15213-3890 
cmeyer at ernest.phys.cmu.edu		http://www.curtismeyer.com/