[Halld-tracking-hw] CDC Drawings

[Tim Whitlatch]

Hi Curtis, Below are answers based on our discussion this morning;  Tim

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?
>
>   
Add chamfer to groove edge on all metal parts.

>     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.
>   
Make all holes .043
> End Plates:
>
>      1) One endplate is still labeled as 6mm carbon fiber. This needs to 
> be fixed.
>   
stay carbon plate
>      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.
>   
Slava found SS inserts in Mcmaster.  Custom studs will be installed.
>      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.
>   
1mm assumed for inner ring. Will look at available thickness. Outer also 
2mm will look at available thickness
>      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?
>   

They should both be the same .002 or bigger
>      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.
>   

for 3/16 roll pin. other for 1/4 screw.
>      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.
>   

note added to ensure this
>      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.
>   
There is some reason to these numbers based on Slava's layouts.
>      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?
>   

For bolting a ring to tie wrap cables to.
>   Cheers -- Curtis,
>
>