Aluminum forward engine mount.

hobot said:

Part of the appeal of slightly modified Commandos is farm equipment technology
spanking moderns where it matter in character and handling bliss.

A note of caution, Al is not good at hi stress vibration or pounding or rubbing impacts. Ms Peel's 6061 T6 cradle is 5/16" thick and her bolts are 7/16" holes.
Hope its over kill but lower front of cradle is known failure point to handle.
Repairs usually add a double thickness up there. Your mileage may vary.

Click to expand...

Thanks for the words of warning. Any wider than .250" and I'll have to machine a recess for the outrigger. Once I've done the program it will be easy to set up to run a set of steel plates, (Riddled with "Hobot" holes for lightness), just in-case.

Will, Ms Peel cradle is 5/16" and I made Maney outrigger fit by taking off meat from back side of dual ajusters and fastening nuts. May work out at .25" though so carry on. I wonder if a swiss cheesed steel version would equal Al in mass or worth the drill bits to find out. I hope to make a center stand and crash bars out of thick wall Al tube. Every bit adds up to ease lift bike up again, with a some limbs not fully functional if at all.

Aluminum is great at bearing loads that are spread out over a large area but maybe not so good at dealing with 5/16" engine bolts and 7/8" swingarm spindles. I would be more worried about stretching then shuffling out the holes than bending the plates. Replicating the stock design in aluminum might be asking for it without some modifications, but it's a great opportunity for some elegant solutions and cool stuff.

Hobot,
No drill bits will be harmed. Turret punch press will delete the mass with a few clicks of the mouse. On the shop floor after loading materiel and pressing start, the pieces will appear after about a minute, as seen on the cad screen with only a few rough edges to sand off.
Bob,
Original P11 plates were made from 1/4" aluminum., but did eventually go oval. Better present day aluminum to try and it only takes minutes to replicate new ones in aluminum or steel after programming is done.

I'll start a new thread when I get a chance at work to program my own projects in a few weeks.

Will

Will, Bob, Al cradles in Nortons is an ancient accepted practice, which revealed long term issues of just replacing with Al in same dimensions as steel plates. As you note its not so much the whole structure at risk but the hi stress points like mount holes. I'm just a messenger from many long term mentors. Ride expert Bob Patton above has been a major one. Run it till holes wallow out some then re-bore for 7/16" bolts, like I did to Ms Peel as a preventive. Her cradle has SS top hat bushes for the center stand pivot - if I ever figure out how to do one to clear the vital to me Patton rear rod linkage - hinge handling load transformer that is worth maybe 20 extra hp or 45 lb less mass - in corner-sweeper speed entry>apex>exits advantage.

7175 T6 is denser heavier than plain Al of 6065 TS, but I use it for high load carriers like drive sprocket and brake rotor adapters. A cradle out of 7075 might weigh almost as much as steel in same dimensions and cost a lot more than 6061.

I don't know what a turret punch is. For my fancy stuff I have it water jet cut.
I'm on look out for fairly hi riser hnadle bars, plenty of short ones out there.
May have to weld up some like they do headers to lose another 1/2 lb or so.
Same with center stand and crash bars on frame and forks.

RGM alloy yokes have to be bigger size than the steel version so only 'gains' less than 1/2 lb off but looks hi tech. Sheet steel yokes are the strongest lightest way.

The first picture was a happy accident, I had this in my toolbox and thought, I wonder. Works awesome. I drilled a bunch of perimeter holes, broke out the center and used it to finish off the hole. Quick and easy.

How fine a find! I'm amazed by what I luck out on when needed, so often makes me wonder about fate's good side showing up more often than not. hobot

I could remove/install gearbox on my Combat, once the rear breather moved to TS cover. Didn't know it was an issue on non Combats, huh. If it was me I'd beef up the plate over the engine bolt holes. Even steel cradle famous for that failure site.

The tranny came out fine with the engine in place on my MKIII.

If I was making alumium front or rear mounts, I would hard anodize them. The steel caps that go on them will otherwise fret them, altering your shim clearance.