Shortly I will be maching a builtup crankshaft for a model single
cylinder engine. The suggested method in the prints is Loctite and
tapered pins or silver soldering. I want to try the Loctite method for
a start. What I am looking for are sugestions regarding methods of
construction that will result in a true running shaft. For example how
best to clamp the parts while the tapered pin holes are drilled and
reamed ie Loctite first then pin or Loctite after all driling and
reaming. The shaft will be .625" how much clearance and what type of
Loctite? Any and all sugestions are welcome.

Jack

rock wrote:

Shortly I will be maching a builtup crankshaft for a model single
cylinder engine. The suggested method in the prints is Loctite and
tapered pins or silver soldering. I want to try the Loctite method for
a start. What I am looking for are sugestions regarding methods of
construction that will result in a true running shaft. For example how
best to clamp the parts while the tapered pin holes are drilled and
reamed ie Loctite first then pin or Loctite after all driling and
reaming. The shaft will be .625" how much clearance and what type of
Loctite? Any and all sugestions are welcome.

Jack

How many throws on the crank?

Make a jig. Think along the lines of a vee block with notches cut to
clear the webs.

Dig around online, and see which of the locking products best suit
your needs.

Look for High strength, close fit, and permanent, as the working
words. Temerature resistant, too.

It used to be easy. Green was for permanent installs, and you needed a
torch to get it apart. Now they have a pile of similar products, all for
slightly different criteria.

Locktite, and others, make a lot of different sealers, lockers, and
shaft adhesives. I cannot recall the number of the product I used for
installing knobs on handles, but it did not take long to set, and has
held up for a year or so of use in our shop.

Cheers
Trevor Jones

Loctite 660

what type of
Loctite? Any and all sugestions are welcome.

Jack

rock wrote:

What I am looking for are sugestions regarding methods of
construction that will result in a true running shaft.

How does it look like? Does it have disks or just arms on the side?
It is a good procedure to make both sides as one part and the split them
(part off, splitting saw). If you machine it from cold drawn steel, stress
relief it before machining.


For example how
best to clamp the parts while the tapered pin holes are drilled and
reamed ie Loctite first then pin or Loctite after all driling and
reaming.

Do you have a drawing? Split con-rod?
There are some tricks how to get it true running with the right setup while
machining. But it depends on how the crank looks like.


The shaft will be .625" how much clearance and what type of
Loctite? Any and all sugestions are welcome.

It doesn't help that much to Loctite and have a press-fit. A perfect
chemical press-fit (AKA Loctite) needs a gap of 0.05 .. 0.1mm (read the
specs!).

It's best to learn to make real press fits. :-)


Nick
--
The lowcost-DRO:
http://www.yadro.de