This mornings project

[Mark Anderson]

Technically started the one on the right yesterday and finished both this morning. After seeing a post on here, I decided to build a dedicated crank measuring stand with dual indicators. Came out pretty nice. Made one for Hughes while I was at it. Nice brake from building boats.

 

[the german]

Looks great Mark !
You have definitely to much time on your hands

Happy Holidays !

Alex

 

[Mike Hughes]

Mark,
Thanks for that. It was on my to do list. With all the other projects going on around here it was going to be a while. Now it is all good.
Mike
Rotted club trailerdoor repair

 

[Terry Keeley]

Very nice, how much runout do you typically see at those points on a new crank? How the hell do you get it straight?

This is the main reason I don't want to run the "RS" style nitro motors, that and having to pull the crank apart to change the rod bearings.

 

[LohringMiller]

Is that a twin in the corner?

Lohring Miller

 

[SayMikey]

Technically started the one on the right yesterday and finished both this morning. After seeing a post on here, I decided to build a dedicated crank measuring stand with dual indicators. Came out pretty nice. Made one for Hughes while I was at it. Nice brake from building boats.


View attachment 332863

That Hughes guy is one lucky dude.

 

[Mark Anderson]

It is an inline twin Lohring. Proof of concept before we go off the deep end on the engine.
Hughes and I have gone back and fourth for years. When we build new toys, many times it is just as easy to build 2.

 

[Mike Byer]

Very nice, how much runout do you typically see at those points on a new crank? How the hell do you get it straight?

This is the main reason I don't want to run the "RS" style nitro motors, that and having to pull the crank apart to change the rod bearings.

In the lathe chuck with one end and tap the other with a lead hammer, usually .008 or so.

 

[Mark Anderson]

Very nice, how much runout do you typically see at those points on a new crank? How the hell do you get it straight?

This is the main reason I don't want to run the "RS" style nitro motors, that and having to pull the crank apart to change the rod bearings.

Terry, I shoot for under a thou. Zenoah cranks are mostly ok new, but I have found them 3-5 out. I have a very precision jig for assembling them that I got from Lohring. If it is too cold in the shop the plates bind on the pins.
Some times one half is twisted around the pin, sometimes the counter weights are not parrallel. So I may clamp or spread the counter weights or hold the crank and tap one counter weight with a brass hammer. The fist few take a bit, but after you figure it out, they go pretty quick. If an engine has a dunk, I will pull the crank and check it. When I refresh an engine the crank gets checked. New engines always get checked.

 

[XtremeRcBoats]

Great project Mark, I think you saw the same post on Jims. I sent Ronnie yesterday a PM about some specs of his Jig.
What thickness aluminium did you use, is that 1/4"?