Re: BCAL base plate

[Tim Whitlatch <whitey@jlab.org>]

Thanks George. We will update the base plate drawing and send it out so 
Alberta can put in their 2 cents.

Cheers,

       Tim

George Lolos wrote:
> Hi Tim:
>
> The top (inner) 8 mm plate will be narrower than the bottom plate and 
> just slightly wider than the top matrix layers.  Something like 9 cm 
> wide.  Its length need not also be as long as the base plate, just 
> long enough to be able to be trimmed together with the matrix to the 
> final length.  I will need to calculate dimensions more precisely but 
> a length of closer to 400 cm (with careful alignment with respect to 
> markers) will do.
>
> I hope this gives some early feedback,
>
> Cheers,
>
> George
>
>
>
> Tim Whitlatch wrote:
>
>> Hi George,
>>
>> Also, the inner 8mm plate will need to be oversized. The length can 
>> be the same as the base plate, should the width be the same amount 
>> wider as the base plate (based on the tapered layup)?
>>
>> Regards,
>>
>>          Tim
>>
>> George Lolos wrote:
>>
>>> Hi Tim:
>>>
>>> The two full prototype modules we built so far had the following 
>>> dimensions for the Al base plate:
>>>
>>> Thickness: 2.54 cm (1").  I guess this will increase now to better 
>>> match the mounting requirements.
>>>
>>> Length:  Minimum length was 415 cm for Module 2 for a final 
>>> (machined length of matrix of 390 cm).   The reason for the extra 
>>> length is to accommodate the length of the base lead layer of ~ 410 
>>> cm that was then trimmed (after epoxy curing) to ~ 400 cm that 
>>> defined the length of the "unfinished" matrix length.  The fibers, 
>>> of course, are longer at ~ 410 cm.   This arrangement allows for a 
>>> comfortable margin of 10 cm for trimming and polishing the two ends 
>>> to a precise 390 cm final length of module.   A longer Al base plate 
>>> will do but serves no purpose.
>>>
>>> Width:  I guess this is the most critical dimension.  We have used 
>>> Al base plates of 15 cm width.  This allows the base Pb sheets of ~ 
>>> 12.8 cm width to be aligned in the center with space on either side 
>>> to use with aligning jigs or pins.  Such width has worked well and 
>>> minimizes Al waste.
>>>
>>> As for the tooling features needed, you're asking the wrong person.
>>>
>>> I hope the above helps.  If we're going to make progress on 
>>> machining a prototype we will need to organize now since with summer 
>>> holidays etc., time will fly and arranging for enough critical 
>>> people to work together will become more difficult.
>>>
>>> Cheers,
>>>
>>> George
>>>
>>>
>>> On 22-May-08, at 2:18 PM, Tim Whitlatch wrote:
>>>
>>>> Hi George,
>>>> It would definitely be helpful to machine a prototype. We need to 
>>>> establish what the initial size needs to be for layup (before final 
>>>> machining with lead). Also the tooling holes need to be worked out. 
>>>> How much extra material is needed on the edges for layup? Also what 
>>>> are the tooling features required? This can be marked up on a 
>>>> drawing and we can incorporate it into the design.
>>>>
>>>> Cheers,
>>>>
>>>>       Tim
>>>>
>>>> George Lolos wrote:
>>>>
>>>>> Hi Jan, Gilbert and Tim:
>>>>>
>>>>> I think we should touch bases again on the issue of precision and 
>>>>> tolerances in machining the Al base plate, as we discussed last 
>>>>> month.   Shall we proceed with machining one plate to full 
>>>>> specifications including alignment reference points to verify 
>>>>> precision and establish the technique?  If the three of you agree 
>>>>> to proceed, then we can discuss the details of when and perhaps 
>>>>> plan for the next meetings.
>>>>>
>>>>> Cheers,
>>>>>
>>>>> George
>>>>>
>>>> <whitey.vcf>
>>>
>>>
>
>
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