Derek,

just popping into my mind.
you need to make the studs firmly to the base plate. bests is to make the thread of the studs a little longer, so you can use a contra-nut to secure the stud. When you remove the head the studs MUST remain firmly in the baseplate. otherwise the accuracy is lost, just as your friend fears.

good luck, Bertus

Bertus,

I'd thought of using the dowels from the cylinder/barrel joint between the baseplate and the head to maintain the accuracy.

Derek,

very good idea. that will work as well.
I believe you'll master this.

Bertus

Derek,

any news?

Bertus

Funny you should ask. I got the baseplate finished last night and I'm about to phone the engineer with the vertical mill today. Hopefully I will have it done in a few days.

Derek,

I'm (we) looking forward to see pics of evidence your engineering skills!!

Bertus

Bertus,

I didn't take any pics of the backplate before I took it to the machinist and since the 50mm thick alloy plate that I used belonged to him he'll want it back after the job's done, but I'll be sure to post a pic of the head with the finished conversion.

Derek

p.s. I got that pair of ST2 barrels and pistons too, so the 907 will be an ST2 under the skin by next spring

[/quote]
17 months old son, wife pregnant with some 50 days left...[/quote]

but this will be good later as they are close enough to play together.
i have daughter & son 18mths apart, well thought out job!!!

Bertus,

I now have an ST2 head with a tacho drive take off

Derek,

very well done!!
thanks for the picture. I'm sure you'll enjoy that mod.

now the next question; will she run this year or are you preparing for next year?
I'm eager to hear your opinion about the results.

Bertus

Next year Bertus, we had our first snow of the winter today

hi Derek,

weatherforecast here predicts also snow, which means the end of a season with very little driving.
it'll be better next year.

bertus

Hmmmmmmmmmm

Now - when I need my bikes altering where do I send them . . . to Derek or Bertus?

Rhino,

difficult decision. Derek is more or less in your area and showed evidence of machining parts
from me, on the other hand there are only stories......
I give a picture of a casting of a John Deere front axle hub. the rolling torque of the wheel bearings is set by machining the bearing contact surface to an exact set value. hard part of the job is getting it all square.
I was trained for conventional turning/ milling and CNC turning/milling and grinding.
when want me to machine parts, feel free to contact me

Bertus

I just found that the ST2 horizontal barrels doesn't have the M12(?) threaded holes that are used to bolt the front lower engine mounts to. All it has is an M6 threaded hole on the RH to take a stud for fixing the battery box mount. I wonder if these lower mounting points are really necessary?