Making a Degree Wheel

[Chris-PA]

Since I've been playing with porting I've wanted a degree wheel, but I've been to cheap and lazy to get one. Recently I've been playing with some 42cc Poulan engines and noticed some strange things, and I decided I needed to measure it. Naturally, I could not bring myself to by one, and also I wanted something chainsaw sized.

The first thing I needed was a disk of some sort, preferably something compact. Now where would I find such a thing? Why of course, a Compact Disc (yes, that was a set up). So I drew a degree disk in AutoSketch (and a little in CorelDraw to get the fonts centered), ans printed it to size on adhesive label material in the laser printer at work.

Then I needed some way to mount it. I tried a couple of things that didn't work, and then I just turned this at work out of a piece of 3/4" aluminum round stock:

It uses some nylon 4-40 screws as set screws so that it won't mar the crank.

Now to figure out what's up with this Poulan engine.

 

[chadihman]

Very nice! I just bought a wheel cheap and also turned my own adapter. My adapter is not as universal as yours. I drilled the center and tapped it to the metric threads on the stihl crank. No wobble though. I didn't trust making my own wheel.

 

[zogger]

Hey, thats slick! Can you post that image you used so it can be printed out life sized? Good use for these coasters here...

I am thinking without a lathe, you could just make several to fit whichever crank they need to be attached to, then use appropriate sized rubber bushings made to size to slide on and fit tight, and glue them on the disks. Then just label them.

 

[Chris-PA]

Hey, thats slick! Can you post that image you used so it can be printed out life sized? Good use for these coasters here...

I am thinking without a lathe, you could just make several to fit whichever crank they need to be attached to, then use appropriate sized rubber bushings made to size to slide on and fit tight, and glue them on the disks. Then just label them.

Thanks!

I'll have to look at the file formats allowed. I want to revise the artwork to show angles plus & minus 180* from zero rather than 0 to 360. This is more typical of how they are discussed here.

Also, I made this one to fit over a 10mm sprocket bearing surface, which seems pretty typical on my smaller saws.

 

[w8ye]

You can buy a vinyl adhesive backed transfer 8" decal from McMaster Carr for $13.95 and stick it to an aluminum plate and hub of your choice.

Here is a link but you will have to pick out the transfer from the degree selection . . .

McMaster-Carr

You don''t have to use an aluminum plate. I've used lite plywood and paper degree wheels from searching with Google. I've mouned them with just the flywheel bolt and no hub.

 

[w8ye]

From this link, they have the stick back ones up to 24" diameter. The 10" is under $10

Adhesive-Backed Dials Outer

 

[Philbert]

There have been a few related threads, including some ideas and graphics to download.

One of the ideas was to use a 3-jaw chuck from/for an electric drill to attach the degree wheel.

Philbert

http://www.arboristsite.com/chainsaw/87920.htm

http://www.arboristsite.com/chainsaw/130069.htm

http://www.arboristsite.com/chainsaw-stickies/177311.htm

 

[Chris-PA]

Those are nice. While larger diameter is better for accuracy, in this case I wanted something smaller as it worked nicely with the little clamshell engine. The accuracy is fine for this work anyway. I actually used some adhesively backed white mylar we use at work.

 

[Chris-PA]

This is how I want to change the markings (from one of the old threads Philbert linked, a comment by w8ye - http://www.arboristsite.com/chainsaw-stickies/177311.htm#post3072234 ):

EDIT - Oh, I looked for an old drill chuck but I couldn't find the drill I was planning on sacrificing. I wonder where I put that thing?

 

[axlr8]

Very nice! I just bought a wheel cheap and also turned my own adapter. My adapter is not as universal as yours. I drilled the center and tapped it to the metric threads on the stihl crank. No wobble though. I didn't trust making my own wheel.

Do you have the motion pro one?! I got mine on the bay for under 16....shipped.. thing is sweet!

 

[Philbert]

CDs are cheap. Print off a bunch and pass some out as prizes at your next GTG!

Philbert

 

[nmurph]

Making your own is great, and very admirable if you can pull it off. The problem is that if the mounting hole is off-center even a few tenths it will put the readings off several degrees, enough to affect the outcome of a porting job. I can't remember which member (Scooter, Frank, or Wiggs come to mind) showed how critical centering the mounting hole was to accuracy.

 

[w8ye]

I was in the back warehouse at work and there was some machinery back there waiting to be amortized out. Some parts had been already been robbed for other machines.

I happened to notice degree wheels all over the packaging machine for use in set up. They were 8" and the center hole was bigger than I desired. So I got a counter clockwise one and made a small aluminum disk from sheet for a new smaller center hole. It has worked well for the last 30 yrs.

 

[Chris-PA]

Making your own is great, and very admirable if you can pull it off. The problem is that if the mounting hole is off-center even a few tenths it will put the readings off several degrees, enough to affect the outcome of a porting job. I can't remember which member (Scooter, Frank, or Wiggs come to mind) showed how critical centering the mounting hole was to accuracy.

That was the problem with everything else I tried, and is why I turned it on a lathe. There is almost no play to the disk, and it fits nicely on the 10mm shaft. And even a 3-jaw chuck can have some wobble

 

[Patrick62]

CDs are cheap. Print off a bunch and pass some out as prizes at your next GTG!

Philbert

Nuts to that, I wonder how many would sell on ebay?

 

[cmarti]

Good job WHW, way to be creative. I am stealing your idea and combining it with a drill chuck. I have widened ports, but have been afraid to go any further. It will not hurt to just measure.............:rolleyes2:

 

[Chris-PA]

It will not hurt to just measure.............:rolleyes2:

Oh yes it will!:msp_biggrin: Oh what the heck, it's too late once you start grinding anyway!

 

[Moparmyway]

Good job WHW, way to be creative. I am stealing your idea and combining it with a drill chuck. I have widened ports, but have been afraid to go any further. It will not hurt to just measure.............:rolleyes2:

What kind of gains did you notice from just widening the ports ?

 

[chadihman]

Do you have the motion pro one?! I got mine on the bay for under 16....shipped.. thing is sweet!

Yup on the bay

 

[cmarti]

What kind of gains did you notice from just widening the ports ?

My 4620 got louder. In all serousness, not sure. I lost the bog in the cut with an 18" bar buried, stronger but no speed demon. I might have got that from the muffler mod. I did both at the same time:dunno: I actually like the saw now, It had struggles stock with a 20" bar