Length of skive for leather belt to drive grinder
 

I am about to make a leather drive belt for an old universal grinder
and think it ought to be a glued joint so as to run smoothly. It
seems reasonable to me that the length of the skive depends on the
thickness of the belt and I was thinking that 5 to 10 times the belt
thickness would be good. But I looked on the internet and found
everyone talking about the length in inches and more inches than I
thought was necessary. The belt is about 3/16 's thick so 5 times
that would be about an inch and ten times it would be just under 2
inches.

So does anyone have experience with making leather drive belts with
relatively short skived joints? Is making the skive 10 times the belt
thickness reasonable?

I happen to have some kevlar roving and was thinking of laying in a
little of that in the glue joint. Not a whole lot, but maybe enough
so that about 50% of the joint is covered with kevlar. I seriously
doubt that anyone has experience with doing that, but would appreciate
comments on why that is a good idea or why it is a bad idea. The
kevlar would be oriented so the strands are running the length of the
belt , not across the belt. My thought is that the kevlar would
prevent stretching which might make the glued joint stronger.

Now there has been a lot of discussion about asking questions in RCM,
so if you do not want to spend any time in answering these questions,
feel free to not reply.

In searching the internet, I found some stuff the Tee-Nut had written,
but did not find his web page on flat belt drives.

Which reminds me. Tee-Nut used to drink New Castle Brown. i recently
had some Brooklyn Brown which I enjoyed even more than the New Castle
Brown. But both are good stuff in my book.


Dan

Length of skive for leather belt to drive grinder
 

" fired this volley in news:965b46a0-
:

So does anyone have experience with making leather drive belts with
relatively short skived joints? Is making the skive 10 times the belt
thickness reasonable?

Dan, that seems really short. I had an old F.E. Reed lathe for years,
one that powered off an overhead line shaft. I have made several belts
for it, both for the main drive and for the longitudinal feed.

The belting manufacturer recommended something around 5-6" for a 3/16"
thick belt, but some of the old texts I read had you making the skive of
a length such that it would pass half-way around the largest pulley in
the system, regardless of what length that was. I tried both at one time
or another, and both always worked; so I presume the shorter skive is
satisfactory.

But my 'shorter' skive was a whole lot longer than your longest 10X
figure.

I also used alligator clip unions, and they worked just as good, but of
course with the repeated clickity-click (which some old machinists told
me sounded like a mother's lullaby to them! G)

LLoyd


LLoyd

Length of skive for leather belt to drive grinder
 

Length of skive for leather belt to drive grinder
 

"Steve W." fired this volley in news:kl9uda$20f$1
@dont-email.me:


3/16" thick leather should have a skive closer to 6"


Dan, that's now two for 6".

Lloyd

Length of skive for leather belt to drive grinder
 

On Wed, 24 Apr 2013 17:25:19 -0700 (PDT), "
wrote:

I am about to make a leather drive belt for an old universal grinder
and think it ought to be a glued joint so as to run smoothly. It
seems reasonable to me that the length of the skive depends on the
thickness of the belt and I was thinking that 5 to 10 times the belt
thickness would be good. But I looked on the internet and found
everyone talking about the length in inches and more inches than I
thought was necessary. The belt is about 3/16 's thick so 5 times
that would be about an inch and ten times it would be just under 2
inches.

So does anyone have experience with making leather drive belts with
relatively short skived joints? Is making the skive 10 times the belt
thickness reasonable?

I happen to have some kevlar roving and was thinking of laying in a
little of that in the glue joint. Not a whole lot, but maybe enough
so that about 50% of the joint is covered with kevlar. I seriously
doubt that anyone has experience with doing that, but would appreciate
comments on why that is a good idea or why it is a bad idea. The
kevlar would be oriented so the strands are running the length of the
belt , not across the belt. My thought is that the kevlar would
prevent stretching which might make the glued joint stronger.

Now there has been a lot of discussion about asking questions in RCM,
so if you do not want to spend any time in answering these questions,
feel free to not reply.

In searching the internet, I found some stuff the Tee-Nut had written,
but did not find his web page on flat belt drives.

Which reminds me. Tee-Nut used to drink New Castle Brown. i recently
had some Brooklyn Brown which I enjoyed even more than the New Castle
Brown. But both are good stuff in my book.


Dan

Machinery's Handbook 22nd (1985) says 4" for leather belts less than
4" wide. MH 10th (1941) shows 5" for 1-2" wide. 6" for 3-4" wide. No
mention in either of belt thickness, which surprised me. I imagine the
recuction in length has to do with better glues.

There's no mention of splicing leather belts in the 26th ed.

--
Ned Simmons

Length of skive for leather belt to drive grinder
 

In article ,
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

Dan, that seems really short. I had an old F.E. Reed lathe for years,
one that powered off an overhead line shaft. I have made several belts
for it, both for the main drive and for the longitudinal feed.

Two FE Reeds (one Inc. circa 1880s, one Makers, which I assume is
earlier) and a Faye & Scott here.

I also used alligator clip unions, and they worked just as good, but of
course with the repeated clickity-click (which some old machinists told
me sounded like a mother's lullaby to them! G)

Unless you are running an antique display that needs to be properly
antique to some time before the clip lacing (what Lloyd calls alligator
clip unions) they are superior in practical use, IMHO. They run
smoothly, and you don't have to cut the belt or take the spindle out if
you need to move the motor or tool (or just the tool, if you are
adequately antique to have a lineshaft bolted to the ceiling beams to go
with it - none of mine do, and it would be hard to replicate unless I
found an old one that hadn't been ripped out for scrap or run without
maintenance before being left to rust for 80 years...)

Depending on how your clips fit the belt, they make either no noise
(belt surface keeps the clip, sunk into the belt just a hair, off the
pulley surface) or a small clicking noise if the clip is at or above the
belt surface.

Skiving and lacing (you might be gluing without laces?) is more of a
home project than clips are, so that may make it better for you if you
don't have a good belt shop handy. I looked at doing it, but found that
a belt shop that could handle flat belting was not really all that far
away. Your "old mill services" availability may vary, but you also may
need to look a little to find it even if it is there.

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

Length of skive for leather belt to drive grinder
 

Ecnerwal fired this volley
in :

clip lacing (what Lloyd calls alligator
clip unions)

yeah...blush, I just could NOT bring that term into my head. Yes,
LACING.

The smaller belt on the longitudinal drive of that F.E. Reed was skived,
glued, and SEWN. (only a little 3/4" belt, so not much to glue on)

LLoyd

Length of skive for leather belt to drive grinder
 

On Apr 24, 6:25*pm, " wrote:
I am about to make a leather drive belt for an old universal grinder
and think it ought to be a glued joint so as to run smoothly. *It
seems reasonable to me that the length of the skive depends on the
thickness of the belt and I was thinking that 5 to 10 times the belt
thickness would be good. *But I looked on the internet and found
everyone talking about the length in inches *and more inches than I
thought was necessary. *The belt is about 3/16 's thick so 5 times
that would be about an inch and ten times it would be just under 2
inches.

So does anyone have experience with making leather drive belts with
relatively short skived joints? *Is making the skive 10 times the belt
thickness reasonable?

I happen to have some kevlar roving and was thinking of laying in a
little of that in the glue joint. *Not a whole lot, but maybe enough
so that about 50% of the joint is covered with kevlar. *I seriously
doubt that anyone has experience with doing that, but would appreciate
comments on why that is a good idea or why it is a bad idea. *The
kevlar would be oriented so the strands are running the length of the
belt , not across the belt. *My thought is that the kevlar would
prevent stretching which might make the glued joint stronger.

Now there has been a lot of discussion about asking questions in RCM,
so if you do not want to spend any time in answering these questions,
feel free to not reply.

In searching the internet, I found some stuff the Tee-Nut had written,
but did not find his web page on flat belt drives.

Which reminds me. *Tee-Nut used to drink New Castle Brown. *i recently
had some Brooklyn Brown which I enjoyed even more than the New Castle
Brown. *But both are good stuff in my book.

Dan

A LOT is going to depend on what you use for glue. You're loading the
joint mostly in shear, which is usually the worst direction for most
glues. The 1" wide belt for the SB 9" has a joint about 6" long. A
long skive is always better than a short one, more surface area for
the glue. Belt thickness is irrelevant. I wouldn't be putting in
anything besides glue in that joint and you need to make sure the two
halves fit very closely. Last new belt I made up, I used a block
plane to do the shaving and tacked both halves to a board to plane
them side by side. The glue recipe I found in an old machinist's
helps and hints book would have made decent model airplane cement, so
I got a tube of Ambroid and used that. Lasted 20 years until I had to
break the belt joint to dismantle the lathe to move it.

Stan

Length of skive for leather belt to drive grinder
 

On Thu, 25 Apr 2013 10:47:16 -0700 (PDT), Stanley Schaefer
wrote:

On Apr 24, 6:25*pm, " wrote:
I am about to make a leather drive belt for an old universal grinder
and think it ought to be a glued joint so as to run smoothly. *It
seems reasonable to me that the length of the skive depends on the
thickness of the belt and I was thinking that 5 to 10 times the belt
thickness would be good. *But I looked on the internet and found
everyone talking about the length in inches *and more inches than I
thought was necessary. *The belt is about 3/16 's thick so 5 times
that would be about an inch and ten times it would be just under 2
inches.

So does anyone have experience with making leather drive belts with
relatively short skived joints? *Is making the skive 10 times the belt
thickness reasonable?

I happen to have some kevlar roving and was thinking of laying in a
little of that in the glue joint. *Not a whole lot, but maybe enough
so that about 50% of the joint is covered with kevlar. *I seriously
doubt that anyone has experience with doing that, but would appreciate
comments on why that is a good idea or why it is a bad idea. *The
kevlar would be oriented so the strands are running the length of the
belt , not across the belt. *My thought is that the kevlar would
prevent stretching which might make the glued joint stronger.

Now there has been a lot of discussion about asking questions in RCM,
so if you do not want to spend any time in answering these questions,
feel free to not reply.

In searching the internet, I found some stuff the Tee-Nut had written,
but did not find his web page on flat belt drives.

Which reminds me. *Tee-Nut used to drink New Castle Brown. *i recently
had some Brooklyn Brown which I enjoyed even more than the New Castle
Brown. *But both are good stuff in my book.

Dan

A LOT is going to depend on what you use for glue. You're loading the
joint mostly in shear, which is usually the worst direction for most
glues.

Picking nit g: Actually, shear is the strongest direction for most
adhesives in most circumstances. It may not be with rubbery adhesives,
depending on their bulk tensile strength. With a thick glue layer,
bulk tensile strength becomes shear strength. With a thin one, it
usually is not. The limit in those cases usually is adhesion.

I don't know what's used for bonding leather belts these days, but the
reason for long skives, as you say, is to give a lot of shear area. If
they're going to give way, it's generally at the ends of the lap,
because the peel strength of most adhesives is inferior to shear
strength. The specific load (load per unit area) is highest at the
edge of a lapped joint of flexible material.

A key example is the way they rivet-bond aluminum aircraft skins. As
with a leather belt, the limiting factor is lifting (peeling) at the
flexible edges. Most of the strength of those joints is the adhesive
in shear, but they put some rivets along the edges to prevent peel.

The 1" wide belt for the SB 9" has a joint about 6" long. A
long skive is always better than a short one, more surface area for
the glue. Belt thickness is irrelevant. I wouldn't be putting in
anything besides glue in that joint and you need to make sure the two
halves fit very closely. Last new belt I made up, I used a block
plane to do the shaving and tacked both halves to a board to plane
them side by side. The glue recipe I found in an old machinist's
helps and hints book would have made decent model airplane cement, so
I got a tube of Ambroid and used that. Lasted 20 years until I had to
break the belt joint to dismantle the lathe to move it.

Stan