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parting board - 12/16/2007 12:45:36 PM   
HO-229



Posts: 228
Joined: 4/30/2004
From: California, MD, USA
Status: offline 		If the plugs left & right half sections have alignment pins that have 99.8+ to100% fidelity in alignment, I see no need for a parting board?

I do not see the parting board adding any value unless the plug is of a one piece construction am I missing something?

My mould halves have alignment pins that join the two halves & to the board that will support it, doing so I have extremely high fidelity

Anyone care to comment


< Message edited by HO-229 -- 12/16/2007 9:05:19 PM >
       Post #: 1

RE: parting board - 12/16/2007 1:17:40 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		If you can supply a picture of your method I might agree with you.

Until then I will advocate the use of a parting board. The use of the parting board results in a flat accurate flange along the joint faces of the mold halves. I join my fuselage halves in the mold, alignment accuracy is paramount. This flange provides an area for alignment pins and clamps for the two halves of the mold. The flange also adds stiffnes to the mold halves. My flanges are always thicker than the glass around the mold form.

Without the flange how do you align the mold halves (Not the plug halves) and where do you place the clamps for the two mold halves?

Ed S

(in reply to HO-229)
       Post #: 2

RE: parting board - 12/16/2007 4:02:31 PM   
SCALECRAFT


 

Posts: 1409
Joined: 1/7/2002
From: MONTEBELLO, CA, USA
Status: online 		229

Where are you alignment pins located if you have no parting board on your molds??

Steve

(in reply to Ed Smith)
       Post #: 3

RE: parting board - 12/16/2007 4:28:57 PM   
seanreit



Posts: 6764
Joined: 4/17/2002
From: Cedar Park, TX, USA
Status: offline 		Even when I create a Left and Right mold from scratch, there is a Faux parting board to face the mold:

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(in reply to SCALECRAFT)
       Post #: 4

RE: parting board - 12/16/2007 5:02:45 PM   
HO-229



Posts: 228
Joined: 4/30/2004
From: California, MD, USA
Status: offline 		HALF SECTION ALIGNMENT

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(in reply to seanreit)
       Post #: 5

RE: parting board - 12/16/2007 5:15:32 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		I think the picture showed the plug halves, correct? The plug, one piece or two piece is not the issue. Mold alignment when joining the fuselage halves is the important factor.

There is a very good reason why every fuselage mold I have made and seen has a flange around the joint face created by a parting board.

Believe me, I will welcome any new ideas that will make things easier and more accurate.

Ed S

(in reply to HO-229)
       Post #: 6

RE: parting board - 12/16/2007 5:21:05 PM   
HO-229



Posts: 228
Joined: 4/30/2004
From: California, MD, USA
Status: offline 		Ed,
This technique is also used for the mould flange & its pin. Alignment I believe is ensured beyond any parting board fidelity.
This technique is only for half section plugs

(in reply to Ed Smith)
       Post #: 7

RE: parting board - 12/16/2007 5:38:58 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		HO-229,

You have lost me completely. Show me a finished product.

Ed S

(in reply to HO-229)
       Post #: 8

RE: parting board - 12/16/2007 5:46:52 PM   
HO-229



Posts: 228
Joined: 4/30/2004
From: California, MD, USA
Status: offline 		Ed,
Steps
Drill left half fuselage for pins
Insert pins
Impress right side fuselage
Drill right side fuselage
Impress Mould flange (left & right @ the same time) (clamped together)
Drill mould flange
Drill mould flange rim for flange to flange alignment

Mate left & right fuselage with dowel pins
Sand or fill plug to match

Utilizing dowel pins insert left half on mould flange half
Do the same for the right

(in reply to Ed Smith)
       Post #: 9

RE: parting board - 12/16/2007 7:36:19 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		HO-229

I think I am beginning to see the light. I will describe it as I see it, correct me if I am wrong.

The two plug halves have alignment pins/holes.

Remove the pins and screw both plug halves down to a flat surface that has been prepared and waxed.

Lay up two mold halves. Remove from the flat surface. We now have two mold halves with a flange with the plugs stuck inside..

Without removing the plug halves from the molds slide the two together on the aforementioned alignment pins.

Clamp tight together and drill the mold alignment pins. Remove the plugs and we now have two mold halves that
should be aligned.

This procedure has merit. It is always a pain to produce a parting board that fits the plug centre line perfectly. The secret here is to ensure that the flat surfaces the plugs are srewed down to are perfectly flat.

Correct??

Ed S

(in reply to HO-229)
       Post #: 10

RE: parting board - 12/16/2007 7:40:06 PM   
HO-229



Posts: 228
Joined: 4/30/2004
From: California, MD, USA
Status: offline 		Ed,
This will make it clear as mud

I’m a picture person

You could screw the plug to the boad but I do not think it will be required.
The dowel pins & a little pressure work well

Remember these flange boards are clamped together while these holes are being drilled

No movement is authorized or you will end up with junk

concerning flatness... not a major big deal, fill voids with fill

you can look at my post that shows an example of the process (Nacell)

http://www.rcuniverse.com/forum/m_6513663/anchors_6676773/mpage_1/anchor/tm.htm#6676773



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< Message edited by HO-229 -- 12/16/2007 8:26:08 PM >

(in reply to Ed Smith)
       Post #: 11

RE: parting board - 12/17/2007 4:44:22 PM   
wkevinm


 

Posts: 141
Joined: 9/17/2004
From: Sherwood Park, AB, CANADA
Status: offline 		HO-229

A very ambitious project obviously you are experienced with complex projects, from what I see your flange serves the same purpose as a parting board, only it appears you make your male plug in 2 pieces. What is the advantage of doing this as opposed to building the plug as one piece and setting in a parting board.

Kevin M

(in reply to HO-229)
       Post #: 12

RE: parting board - 12/17/2007 6:22:09 PM   
HO-229



Posts: 228
Joined: 4/30/2004
From: California, MD, USA
Status: offline 		Kevin,
First, all this stuff is subjective & the user defines what is best for his/her needs.

I find the following to be true in my case, it would be best for you to form your own opinions

The below are my comments/opinions

1) I do not concern myself with complex alignment jigs
1A) The FRL & shape at the subject FS station is all that matters
2) It is easy to find a flat surface upon to do the build utilizing the half method scheme
3) Errors are easily corrected utilizing the half method scheme prior to fabricating the mirror image side
4) fidelity is ensured if not guaranteed
5) I am defining the project from own plans & drawings, I am not utilizing someone else's plans.
6) The parting board scheme has only the level of fidelity of the craftsman manufacturing it
7) simple
8) less time & material to manufacture
9) It does not matter were the powel pins are located or how many
10) joining/separating the left & right halves is quick & facilitates sanding & filling

I believe the parting board technique has its place if reproducing aircraft that are whole

Hope this helps

Regards,
Dave

(in reply to wkevinm)
       Post #: 13

RE: parting board - 12/17/2007 6:35:07 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline
quote:

You could screw the plug to the boad but I do not think it will be required.
The dowel pins & a little pressure work well

Remember these flange boards are clamped together while these holes are being drilled

No movement is authorized or you will end up with junk

concerning flatness... not a major big deal, fill voids with fill


I do not agree with some of the above. When joining fuselage halves in our out of the mold an accurate split line is of paramount importance.

A bowed flange or voids will create unsolvable problems with fuselage alignment.

Ed S

(in reply to HO-229)
       Post #: 14

RE: parting board - 12/17/2007 7:01:52 PM