Trouble Fitting Swing Arm to Gearbox Cradle

Thanks Les for your encouragement. When my temperament settles down I will get back to the shed and the work at hand. Maybe tomorrow afternoon.

Cheers
Don

thunderbolt said:

BTW you can see the machining marks on the cradle now the coating is removed.

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BTW, the cradle of the flood bike looked almost exactly like this, with a thick coating of paint and rough edges around the pivot holes showing the thickness of the paint. The machine has never been apart until I broke it down to pieces, so whatever paint or coating is on there came from the factory in 1973.

I wonder how smooth that machining is. Looks like the blades of a file, and we know what they are good for.

Dereck

kerinorton said:

I wonder how smooth that machining is. Looks like the blades of a file, and we know what they are good for.

Dereck

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The machining is smoother than it looks. If it was filed then he is a better hand tool man than me. It would have had to have been filed in a circular motion.

Some more progress today, a few pics for those following the the thread.

All the powder coat has been removed and left with the bare cradle to be masked and painted.








Next job will be to but some bolts and washers to mask up the engine bolt holes on the cradle and mask up the swing arm area and isolastic parts of the cradle.

Cheers
Don

Ron can you give a further explanation of the paints you have mentioned above please. "A good coat of epoxy primer" -- is this brushed on, spayed on from a can or spray gun, etc.

"Lay down an epoxy primer and black acrylic urethane topcoat" -- again is this spayed on or brushed? If sprayed what is the procedure. I will have no trouble removing the powder coat - if the CRC is left long enough the epoxy just crinkles up and practically falls off. I did not leave it quite long enough on the first side I did and a bit of scraping was involved, but on the second side it just fell off.

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To the clean, bare steel I prefer DP90LF (Black) or DP50LF (Gray) primer and DP402LF Catalyst (by PPG), but others have had excellent results with Southern Polyurethanes (SPI) epoxy primer. For color I like PPG Concept DCC9300 Black Acrylic Urethane. Both primer and color are sprayed with an HPLV gun.

I would coat all surfaces with the primer and color, but in the swingarm bearing area only use enough paint to give a solid color. This will be considerably less film than the powder coating.

by thunderbolt » Tue Feb 14, 2017 2:28 am

kerinorton wrote:
I wonder how smooth that machining is. Looks like the blades of a file, and we know what they are good for.

Dereck


The machining is smoother than it looks. If it was filed then he is a better hand tool man than me. It would have had to have been filed in a circular motion.

Some more progress today, a few pics for those following the the thread.

All the powder coat has been removed and left with the bare cradle to be masked and painted.

What I said was, that the surface looks like the surface of a file. It has to be perfectly smooth or the hat bushes will become toast. [ ie the bronze bushes will wear out ]
Dereck

kerinorton said:

What I said was, that the surface looks like the surface of a file. It has to be perfectly smooth or the hat bushes will become toast. [ ie the bronze bushes will wear out ]
Dereck

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Sorry Derek for misquoting you. Unintentional. I'm going to the shed now to check how smooth the machined surface really is.

Thanks Don

SeeleyWeslake said:

It doesn't seem to have been mentioned yet.
We can't quite see all the cradle in the pictures but you need to do the powder coat removal thing on anywhere there is a bolt head or washer or nut face as well as the area where the engine and gearbox cases meet with cradle. If you don't, things like the engine mounting bolts will work loose in use with bad consequences. I'm a bit surprised AN supplied the cradle with so much powder coat on it. I guess it stops it rusting when sitting on the shelf.

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Here is the cradle after it has been stripped of all the powder coat and resprayed with two pack apart from the parts masked up as suggested above by Seeley.







Also had the oil tank painted at the same time. It pays to have a good mate as a spray painter.



Just waiting on the shim to arrive in the post, cut it to size and then refit the bushes and hope it all fits well without any play in the swing arm - then it can go in the freshly painted frame.

Cheers
Don