Hello folks, I built a sawmill a couple years ago and all the manual
moving of logs has got me a bit depressed. Now I'm thinking about
building a log loader which is basically a front loader like arm with
a grapple. I haven't started designing or building this yet just
thinking it out a little.

At the hinge points I will be using hardened pins but I'm not sure of
a couple things.

1. how to size them (if someone could point to an equation let me
know) or I'll just way oversize them and forget calculating them.

2. should these pins be in bushings and if so what material should
these bushing be?

I've been trying to get a close look at front loaders but haven't seen
any around lately LOL.

Any assistance would be appreciated.

Thanks

On Mon, 27 Aug 2007 13:48:22 GMT, Modat22 wrote:

At the hinge points I will be using hardened pins but I'm not sure of
a couple things.

1. how to size them (if someone could point to an equation let me
know) or I'll just way oversize them and forget calculating them.

2. should these pins be in bushings and if so what material should
these bushing be?


Machinery's Handbook has the information you need in the section on
plain bearings. Since this is a slow speed app, you're interested
primarily in the load bearing (pressure) capacity of materials rather
than PV (pressure x velocity) limits. Ability to run in the presence
of dirt is also presumably a consideration.

--
Ned Simmons

As an engineer, years ago, I became quite fond of the term, shamelessly
plagiarized. Find a grapple and copy it. Worth your time to look around.
You'll do even better if you find two different models and take the best
from each.

Nearly all units like this have 1" pins. Use McMaster Carr W1 grade for the
material. I've not seen bushings on backhoes and loaders. I suspect you
won't on grapples either.

Karl

On Aug 27, 6:48 am, Modat22 wrote:
Hello folks, I built a sawmill a couple years ago and all the manual
moving of logs has got me a bit depressed. Now I'm thinking about
building a log loader which is basically a front loader like arm with
a grapple. I haven't started designing or building this yet just
thinking it out a little.

At the hinge points I will be using hardened pins but I'm not sure of
a couple things.

1. how to size them (if someone could point to an equation let me
know) or I'll just way oversize them and forget calculating them.

2. should these pins be in bushings and if so what material should
these bushing be?

I've been trying to get a close look at front loaders but haven't seen
any around lately LOL.

Any assistance would be appreciated.

Thanks

Just don't forget the grease fittings.

dennis
in nca

On Mon, 27 Aug 2007 13:48:22 GMT, with neither quill nor qualm,
Modat22 quickly quoth:

Hello folks, I built a sawmill a couple years ago and all the manual
moving of logs has got me a bit depressed. Now I'm thinking about
building a log loader which is basically a front loader like arm with
a grapple. I haven't started designing or building this yet just
thinking it out a little.

At the hinge points I will be using hardened pins but I'm not sure of
a couple things.

1. how to size them (if someone could point to an equation let me
know) or I'll just way oversize them and forget calculating them.

That's my preferred plan. Better too strong than too weak, right?
Weight is the only other consideration. Find balance, Grasshoppa.


2. should these pins be in bushings and if so what material should
these bushing be?

These guys might be of service:
http://www.backhoeplans.com/
http://www.ubuilditplans.com/webpage4_page2.htm
http://cdp-backhoe.com/plans.htm

Or just buy cheapies from HF. Call to find part numbers.
http://www.harborfreight.com/cpi/cta...emnumber=93167

------
We're born hungry, wet, 'n naked, and it gets worse from there.

On Aug 27, 9:48 am, Modat22 wrote:
Hello folks, I built a sawmill a couple years ago and all the manual
moving of logs has got me a bit depressed. Now I'm thinking about
building a log loader which is basically a front loader like arm with
a grapple. I haven't started designing or building this yet just
thinking it out a little.

At the hinge points I will be using hardened pins but I'm not sure of
a couple things.

1. how to size them (if someone could point to an equation let me
know) or I'll just way oversize them and forget calculating them.

2. should these pins be in bushings and if so what material should
these bushing be?

I've been trying to get a close look at front loaders but haven't seen
any around lately LOL.

Any assistance would be appreciated.

Thanks

I built a front end loader a few years ago and got a sawmill running
earlier this month.

The simplest way I know to move logs is shear legs set up at one end
of the sawmill track so you can lift logs out of a truck or trailer
and lower and position them on the track. I used 2" pipe for the shear
legs with a chain fall hanging in the center and block-and-tackles
tied to large trees on either end to pull the rig from side to side.

The front end loader is built on a Sears GT18 garden tractor, which is
too small to lift 400 - 700Lb oak logs. It's already blown both front
tires moving wet snow.

I used O-1 drill rod for the pivot pins and brass water pipe for the
bushings on the front end loader, although as someone else noted
commercial loaders run steel on steel and grease daily. The biggest
problem was retaining the pins. I TIG welded flat plates on one end
and bolted the plate to the frame but several of the welds broke at
the end of the heated zone. I packed the rest in charcoal and annealed
them, losing a little surface finish but ending the breakage.

Jim Wilkins

In article ,
Modat22 wrote:

1. how to size them (if someone could point to an equation let me
know) or I'll just way oversize them and forget calculating them.

2. should these pins be in bushings and if so what material should
these bushing be?

The bigger the pin, the lower the (unit) pressure. That makes for
happier bearings. My backhoe (which makes pretty good log mover with
some hooks and chain) is bushed, but it's bushed with steel on most of
the serious points. Some of the steering is bushed with bronze. Grease
daily - partly for lube, partly to keep moving the dirt out. I rebushed
some points with a steel-backed teflon bearing of very high PV from MSC.

If it's bushed, even with plain steel, you just drive out the bush and
put in a new one - simple. Often the bushes are also hardened, and you
replace bushes and pins as a set - they may also be soft, and you
replace just the bush most of the time.

If it's not bushed, or (thank the idiot that had my backhoe before I was
dumb enough to buy it) worn so far that the wear is outside of the
bushing, you need to weld it up and line-bore it - a pain in the
buttocks, specialized equipment, etc...

--
Cats, coffee, chocolate...vices to live by

"rigger" wrote in message
oups.com...
On Aug 27, 6:48 am, Modat22 wrote:
Hello folks, I built a sawmill a couple years ago and all the manual
moving of logs has got me a bit depressed. Now I'm thinking about
building a log loader which is basically a front loader like arm with
a grapple. I haven't started designing or building this yet just
thinking it out a little.

At the hinge points I will be using hardened pins but I'm not sure of
a couple things.

1. how to size them (if someone could point to an equation let me
know) or I'll just way oversize them and forget calculating them.

2. should these pins be in bushings and if so what material should
these bushing be?

I've been trying to get a close look at front loaders but haven't seen
any around lately LOL.

Any assistance would be appreciated.

Thanks

Just don't forget the grease fittings.

And just as important is to USE those grease fittings.

Can't tell you how many times someone comes in the shop to have a bearing
like thing bored out "because the damn thing is made so cheap, it doesn't
last" only to find out that the thing hasn't seen grease since it was
built....10 years ago.

Mike

On Mon, 27 Aug 2007 22:27:16 GMT, Ecnerwal
wrote:

The bigger the pin, the lower the (unit) pressure. That makes for
happier bearings. My backhoe (which makes pretty good log mover with
some hooks and chain) is bushed, but it's bushed with steel on most of
the serious points. Some of the steering is bushed with bronze. Grease
daily - partly for lube, partly to keep moving the dirt out. I rebushed
some points with a steel-backed teflon bearing of very high PV from MSC.

If it's bushed, even with plain steel, you just drive out the bush and
put in a new one - simple. Often the bushes are also hardened, and you
replace bushes and pins as a set - they may also be soft, and you
replace just the bush most of the time.

If it's not bushed, or (thank the idiot that had my backhoe before I was
dumb enough to buy it) worn so far that the wear is outside of the
bushing, you need to weld it up and line-bore it - a pain in the
buttocks, specialized equipment, etc...


Hadn't thought about using hardened bushings, that's a really good
idea and pretty easy to do.

Thanks everyone for the replies.