Darkhorse Universal Pinion and Sprocket Shaft Runout Tool Kit

[Ohio HD]

This is a great design. Simple, but really a great idea. DH has a fixture that will allow you to measure pinion and sprocket shaft runout for '70 and up Shovels, all Evolution, all Twin cam and all M8 motors. Just looking at this makes you realize just how over built all of the current runout tools are. I mean there is no pressure from a dial indicator to speak of. One bolt will hold the fixture just fine.


https://darkhorsemoco.com/products/man-o-war-sprocketshaft-run-out-tool

[Ohio HD]

So I changed the title of the post to add sprocket shaft. When I went to the DH web site to look at the tool they speak about it being able to also measure the sprocket shaft side. They also say they include five small cylindrical magnets to determine if the fine splines are cut off center on the sprocket shaft.

So now my curiosity is peaked and I ordered one. Stay tuned.   

[Ohio HD]

Here are the photos from DH where they use the fixture to measure sprocket shaft runout. I really don't know why they supply five magnetic pins, it would make more sense to me to use six. The pins would be spaced out evenly. See my drawing below, five pins vs. six pins. I hope there's some instruction in the tool kit that speaks to their reasoning for five pins. Otherwise I'll be calling them.











You cannot view this attachment.

[FXDBI]

One spare pin, you only measure 4 spots in 90 degree increments.  Bob

[kd]

I expect if you have an even number of pin you are in fact measuring the same deflection twice.  If you do the math, 4 = 2 points and 6 = 3 points when considering the off side being the opposite of the other.   An uneven number like 5 gives you 10 points of deflection around the circumference.

I notice there isn't a 90 degree angle on the gauge post contact spot when measuring.  IMO that would give a reduced deflection distance measurement. either.  You could probably calculate a more accurate deflection distance if you know the angle.

[Ohio HD]

I agree that you measure the defection deflection twice when they oppose each other. But that's how you find a low spot and a high spot, if there is one. I've actually mapped out a sprocket side reading with all 24 peaks and a dial indicator. A real pain in the posterior. But it gives an accurate picture of what you have.

[kd]

I agree that you measure the defection twice when they oppose each other. But that's how you find a low spot and a high spot, if there is one. I've actually mapped out a sprocket side reading with all 24 peaks and a dial indicator. A real pain in the posterior. But it gives an accurate picture of what you have.

I now map cylinders every 45 degrees and in increments of 1" in depth.  It's interesting how well you can get a true picture of the shape.  It helped me on one occasion trouble shoot and understand ring rotation stall.

[FXDBI]

I agree that you measure the defection deflection twice when they oppose each other. But that's how you find a low spot and a high spot, if there is one. I've actually mapped out a sprocket side reading with all 24 peaks and a dial indicator. A real pain in the posterior. But it gives an accurate picture of what you have.

Yes zero the dial rotate shaft 180 the reading is double the actual doesnt matter if its + or - that just tells you the direction of the bend. Do 2 sets of readings one for each set of 180 points take 1/2 of each reading and  that will tell you if its straight or how its bent. I have played around lots with the dials on my twin cam cranks both in the case and on V-blocks. Straightened and TIG welded the pin on my 4in crank ran it for a couple years. Pretty easy to move the dial pushing sideways on the shaft. I think a tight primary chain on a hot engine will put a set in it another good reason for a good warm up before getting on it. Enjoy the NEW tool Ohio.   Bob

[Admiral Akbar]

They need to supply a flat foot for the indicator and a knob instead of set screws for the indicator holder.

[Ohio HD]

You're right. I bought a set if indicator plunger ends, had two flat adapters with the kit.

We can make a poor mans handle for a screw. Drill a hole in a small plastic ball and epoxy it together. I guess if a man wanted to spent time on it you could make a small knurled aluminum barrel to epoxy over a screw.

Hell I might just use a 22 casing and epoxy it on a screw.

[Ohio HD]

I've got 15 pins total now, as I bought 10 more from DH. I need to measure a crank before splitting the cases, maybe this month if I get caught up. I'll use 12 of the pins.


You cannot view this attachment.