startin' on a Webster

[Brian Rupnow]

How are you going to make your own gears? Do you have a set of gear cutters or are you going to grind a single tooth cutter and do it that way.--Brian

 

[Paulsv]

Plans and parts for the propane valves are also available from Jerry Howell's website:

http://www.model-engine-plans.com/engineplans/bookshelf/demandvalve.htm

 

[dgjessing]

Thanks for all the advice you guys - I'm mulling things over . I'm planning on cutting the gears with a single tooth fly cutter kinda thing.

More work on the head today! Drilled the plug hole (undersize for now) and bored the cylinder recess in the four jaw on the lathe:

I then moved the chuck & part to the rotary table on the mill without disturbing the setup. It was not quite parallel to the table with the RT set to zero, so I used a dial indicator to find parallel:

... then used a piece of tape with a pencil line on it to show a temporary new zero mark on the RT:

Finished drilling and counter boring the screw holes and the recess for the spark plug (remember I've got an extra 1/4" thickness which I plan to cut cooling fins in):

I then milled the notch for the frame member and drilled and tapped for the connecting screws, the removed the excess thickness where the cooling fins will not be:

And here's the whole thing so far set together:

 

[Blue_Rock]

Hi Dave, nice progress with your build... I'm enjoying your thread! Looks like you will overtaking me before too long. Keep up the good work.

 

[dgjessing]

Fins!

Yes, one of the cuts is in the wrong place - I mistook .225 for .250 : Let's just ignore that, OK?

 

[rebush]

Dave: I'm really enjoying the picture and description of your build as you go. I've always picked things up quicker by seeing something done than by reading about the same procedure. Your doing a great job and thanks for sharing. Roger

 

[dgjessing]

Not a heck of a lot new:

Cut a piece for the base, but everything is just sitting there in the picture. Drilled and tapped the cylinder for the head bolts (does a 4/40 screw qualify for the name "bolt"?), drilled the transfer port, and drilled and tapped the valve block mounting holes.

I've worked out the details of the timing gears using a cutter I've already got. Mine are going to be a bit larger in diameter than what the plans call for, which will shorten the exhaust valve rocker arm somewhat.

Now I'm thinking about a Jan Ridders style vapor carb arrangement. But that's down the road a ways; plenty of time to change my mind on that

I was disappointed not to find a Webster example at the NAMES show this past weekend

 

[Blogwitch]

Dave,

I do like it when people stray from the religious 'have to built it exactly to the plans' route and start to 'fiddle' things along by using what they have, rather than spending more money on items they will most probably never use again.

The finned head on there looks like it really belongs, and I am sure your gears will be just fine.

Keep it up.


John

 

[dgjessing]

Laid out the holes in the base on the bottom with pencil, since that's the reverse of the drawing, and I wanted to make sure I didn't screw it up on the mill. Actual location of the holes & counter bores done with the DRO on the mill:

(There is a piece of plywood under there to protect the mill's table)

And here is the assembled underside. I used all 10-24 cap screws instead of the 6-32 and 10-32 flat heads specified:

So there you have it so far:

I also picked up an M10x1 tap and did the spark plug hole today. Kinda neat to have a big assembly to look at instead of just a bunch of parts ;D

 

[rhitee93]

You are chugging right along. I am enjoying the build so far!

 

[vcutajar]

Dave

I am following your build also. I never stop learning new things.

Vince

 

[ozzie46]

I'm following along too as the Webster is on my "to do" list. You're doing a good job.

Ron

 

[dgjessing]

Thanks, everybody!

Worked on the crankshaft today. First made the bronze bushings and found a piece of 5/16" steel for the shaft:

I then roughed out the crank web and drilled and reamed holes for the shaft and crank pin:

The setup to mill the crank web sides equal:

Welded the web to the shaft:

... and cleaned that up on the lathe:

Next I brazed in the crank pin:

And here is the (*more or less) finished crankshaft in place:

* I've actually got a bit more work to do on the crank pin - it's a little crooked... I'm thinking I'll turn it down in diameter a little to fix that. I hope to do that with a boring head on the mill, cutting the outside diameter. Unfortunately though my mill won't turn in reverse, so I'm going to have to come up with a "left handed" boring tool to do it.

 

[Blogwitch]

Dave,

To get around that sort of problem if ever you need to do it again is to turn the spigot that goes into the hole slightly smaller.

Then put a straight knurl on the spigot so that it is a tight fit in the hole. Press the two parts together in say your vice, and then silver solder from the back.

The press fitting will hold the crankpin exactly square because of the shoulder you have machined on it, and the silver solder will fill up the knurled recesses on the back, making sure that the pin stays put.

John

 

[dgjessing]

I had a nice snug fit until I welded the shaft - the heat from that produced some scale inside the hole which needed to be sanded out. I should have saved reaming the crank pin hole until after the weld job... :

 

[cfellows]

Looks like you're making good steady progress, Dave.

Chuck

 

[bearcar1]

Man I do like those fins in the cylinder head, Dave. I'll be watching with interest as I think that you will have a few more surprises for us to look forward to.

BC1
Jim

 

[dgjessing]

Well this was kind of a nail-biter...

Starting to cut:

Done, 1/1000 th at a time:

Much better! Now on to the connecting rod!

 

[dgjessing]

Did the odd size big end on the lathe. Kind of an odd setup too, but hey:

Also kinda odd, I marked the major diameters of both ends on the lathe by holding the rod in this arbor. Just barely cleared the bed...

Then lots of milling, sanding and fitting later, here we have it:

That nylon washer is temporary. I now need to make a new main bushing for the crank end that has the appropriate extra length sticking out of the frame to hold the crank in the right place.

 

[rhitee93]

Nice
That lathe setup for the big end sure looks intimidating. From the pic it doesn't look like it clears the bed