Author Topic: A31 support plate of cam spindles  (Read 2553 times)

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Offline roberto

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A31 support plate of cam spindles
« on: 08 Feb 2015 at 18:59 »
Hi,
I am working on an A31 motor.
The support plate of the cam spindles is missing.
Has someone a drawing for me, to reproduce this part?
Is it made of steel or aluminium?
Hor thick is this plate?
What dimension have the 3 screws?

Thank You for assistance
Roberto

Offline Doug

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Re: A31 support plate of cam spindles
« Reply #1 on: 09 Feb 2015 at 23:13 »
Hello Roberto,

I have an A31 awaiting restoration. If you cannot locate these parts, I can make you a drawing. The parts should be the same through the 1936 250/350cc models. The plate is steel. I should also have a sample of the bolts.

-Doug

Offline Dave

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Re: A31 support plate of cam spindles
« Reply #2 on: 10 Feb 2015 at 23:38 »
This post from Roberto was made during a change of server by the hosting company and missed being transferred from the old server to the new server. Fortunately, Doug received a notification email with the text so we are able to continue the conversation.

Quote from: Roberto
Hello,

I think, i will make a laser cut sheet metal part for this. The outside contour i get, when I enlarge the grafic on the copier. I presume the support plate is 4-5 mm thick. The exact dimension would be helpful.

The distance of the cam spindles is difficult to measure exact. I measure 85,7 +/- 0,2 mm. Can it be, that the nominal distance is 3 3/8" (85,72 mm)?

The dimension of the 3 fixing screws seems to be 3/8" x 24G. Where can I get this screws !?

Roberto

Offline Doug

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Re: A31 support plate of cam spindles
« Reply #3 on: 10 Feb 2015 at 23:45 »
Roberto,

The cam spindle distance is a function of the gear centers. It is 1.6666 inches above and below the crankshaft. The other mounting bolts distances are nominal fractions.

The mounting bolts are 5/16-25, a proprietary Douglas thread.

I sent you a PM regarding drawings.

-Doug

Offline roberto

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Re: A31 support plate of cam spindles
« Reply #4 on: 27 Feb 2015 at 14:12 »
Thank you Doug for the drawings!
I made a dxf file of the drawing so I could order a laser cutted sheet metal part.
It fits pefectly!

If someone needs this dxf file - please let me know.

Instead of the 5/16x25 bolts I used M8x1  (not for purists, but it works...).

Best regards
Rupert