Briggs & Stratton 6S - A Beginnig

[arnoldb]

Simply STUNNING Bill :bow:

Kind regards, Arnold

 

[b.lindsey]

Thanks Arnold. So far its fitting together nicely...as few little issues here and there but nothing too bad yet.

Bill

 

[Deanofid]

Thanks for the new pics, Bill. It looks fantastic!

 

[zeeprogrammer]

Every time I pop in here I have to say to myself...impressive, beautiful, excellent craftmanship...I usually end up muttering 'sheesh...someday I can do that'.

 

[b.lindsey]

Thanks Dean and Zee. Zee, I am a firm believer in the notion that once the basic skills are mastered (which you have accomplished), the rest is just a matter of chaining more steps or more set-ups together to do more complex things. Experience comes into play in helping plan ahead, seeing one or two or three steps down the road, remembering what worked before and what didn't,maybe avoiding a few mistakes (which I still make plenty of), or maybe doing things a bit faster (all evidence in this build log to the contrary) ;D The point is just keep after it...you CAN do it!!

That said, I had a fun time pinning the crankshaft together this afternoon...NOT!! It all went well just slowly. The thing about taper pins unlike straight dowel pins is that the deeper you ream the more surface area there is to ream due to the taper angle. I center drilled the crank arms, drilled through slowly with a 1/16" drill the enlarged each hole halfway through with a #51 drill (.067") which made the reaming go a little easier. The straight flute taper pin reamer is for hand use so I put it in a small drill chuck and turned it by hand in order to feel it better. Every 4-5 rounds I took it out, cleaned the flutes, and dipped it in some dark thread cutting oil for lubrication.An hour or so later I had both holes reamedjust to where the taper pins would fit all the way through. This is shown in the photos below. Photo 1 shows the drilling set-up, photo 2 the two drilled holes, photo 3 the reamer just coming through and photo 4 the entry side of the holes with the right hand hole alre3ady reamed

 

[b.lindsey]

The last three photos for now show the first pin kisy peeling out of the small end of the hole, both pins from the entry side, and lastly the small size of the reamer itself...doesn't look like 30+ dollars does it, but thankfully it survuved. The pins still need to be loctited in and the excess cut off from the entry side, and I still have to pin the crank gear to the shaft but need to locate it more precisely first and make a timing mark on that side of the crank. That will be another day though!

 

[b.lindsey]

Thanks for checking in Pat...but the saga continues. When I tried to fit the original shroud (the white cover) over the crank/flywheel/starter hub, there was interference between the front of the flywheel and the inner front side of the shroud That was easy enough to fix...just changed the Solidworks file and ran another RP model which worked fine. Actually the newer dimensions are closer to the prototype and this was at least a minor change. The results of the new one are shown in the photo. Yesterday morning I was going to attempt to fit the crankshaft/plate/shroud assembly into the crankcase and DRATS!!! the major OD of the crankshaft is 1.438 and the hole through the crankcase is 1.375" ....hmmm that ain't gonna work!! No doubt in the early design work on the crankcase I used a little design liscense trying to be conservative but at the same time not looking far enough down the road and seeing this roadblock. Since the holes for mounting the plate to the crankcase have already been drilled and the mounting ring already cut into the face of the crankcase (see photo 2) the options were/are as follows:

1)Enlarge the hole in the crankcase to 1.438" - possible, but that leaves too little material on the inside of the four mounting holes. This would also mean remaking the ring on the back of the plate which fits into this hole. Not a great option.

2) Cut down the center part of the crankshaft to 1.375" - also not a good option since that would basically eliminate the small shoulder above the crank pin. I did consider taking the full 1/16" in diameter from just the counterweights, but then the whole crank is not symmetrical and the weight may in fact be needed.

3) Remaking the crankcase/plate/mounting ring - not a chance

4) Enlarge the crankcase bore to 1.425" and shave a mere .006-.007" off of the OD of the crankshaft - This leaves a little more material on the inside edge of the mounting holes and keeps the symmetry and crankpin shoulder of the crankshaft. It will still require remaking the mounting ring on the back of the plate but that is a pretty minor penalty for this lack of foresight. So this is the direction I am going to try...stay tuned

 

[b.lindsey]

Am hoping to get started on the correction to the crankcase today. Meanwhile I figured I would need something on the wooden base to house all the ignition components (planning to use the CDI ignition from S/S Machine & Engr.) so more of the brown stuff to make a little box for that. It looks HUGE in the pictures but in reality it is only 3" high x 5" long x 3" deep. Once the rest of the engine is sitting on the base it shouldn't look quite as disproportional. Anyway, here are a few pics of that.

 

[NickG]

Wow, got brown stuff envy now! Is that glued together or some sort of lap joint similar to frame? :bow:

Nick

 

[b.lindsey]

Hi Nick, the box is just held together with butt joints and glue, sorry, no fancy dovetails or lap joints. All it has to do is look decent and hold together. Wouldn't want it to detract from the engine once its in place now would I? :big:

Bill

 

[arnoldb]

True eye-candy every time I check in Bill :bow:

Sorry to hear about the crank clearance; I'm sure you'll soon have that sorted out though!

Kind regards, Arnold

 

[Deanofid]

That skid and box are going to look great with the engine, Bill. Thm:

 

[joe d]

Bill

Looking good. So: what did you finally use for the finish?

Joe

 

[b.lindsey]

Thanks for looking in Arnold, Dean and Pat. Joe I tried the Varethane using foam brushes and it seemed to work out very well. In the pictures of the box above it had only been stained at that point. I also did the finishing at work where it could be left in a warmer environment overnight as well.

Bill

 

[b.lindsey]

Hasn't been a productive week and had to be in Houston for 4 days as well, but have managed to get back to where I was. The crankcase opening was bored out and a new bushing retainer was made to fit the larger hole. The crank diameter was reduced just enough to fit the new hole...checked it this time before assuming....duh! Anyway now back to the crankcase so I can start hanging the various components off of it so it will start looking like the engine it is supposed to be.

 

[steamer]

Geeez Bill that's looking Awesome!.....I'm digging this build for sure.

When and If you get plans together ....I'll be in line.

Dave

 

[b.lindsey]

Thanks Dave, and yes theere are plans,but still being finalized as the build progresses.

Bill

 

[steamer]

Ya know bill...I can still smell the rank oil on the inside of that old briggs when I too it apart some 30..mumbble mumble mumble years ago......I bet I took it apart and put it together about 15 times ....just to say I could....cool build!

Dave

 

[b.lindsey]

Dave, my Dad used to bring home old air compressors and i would do the same thing,,,take them apart and put them back together over and over. I was probably 7 or 8 at the time so I guess something "took."

As for this evenings post. I did get a start on the backside of the crankcase, locating and milling to depth (how much they will stick out) the various bolsters on that side of the crankcase. Then I scribed a few lines more to indicate where NOT to mill away material...mostly where the angled webs willl be located. Figured this would be a good idea sine i've already tried to kill this thing off once. :big: Not too much to show yet but a couple of pics none the less.

 

[b.lindsey]

Switching sides of the crankcase I began milling our the area where the tappets and valve stems meet...whatever one might call that area. Its tough to get much machine time as all the senior engineering students have been working diligently on the prototypes for their projects and that has priority as it should. But small steps are better than none so the crankcase if lighter by a half ounce or so anyway. (photo 1).

I have also been working on the idea of printing decals on 3M clear permanent adhexive label stock. I found some with full 8 1/2 x 11 sheets and since they can only be run through the printer once I laid out a whole sheet of 6 sets so if it does work I will have some to play with ans see how durable they are, etc. These were all done in AutoCAD, two of them fit on the air cleaner (one on top and one on the side) and the other is the logo decal that will fit on the shroud. They print fine in color on regular paper but I don't know yet if they will print well on the clear stock, and how opaque they will be. In any event its been a fun little diversion while waiting on some machine time. I will try printing them on the label stock tonight so keeping my fingers crossed : The sheet layont is shown in the .pdf file by the way.

View attachment B&S Decal Layout1 (1).pdf