New Old Continental Band Saw.............

[brino]

Okay this saw has been waiting far too long!

I will show a little bit of the motor controller in another post......I got lucky that this one just needed an analog voltage to vary the motor speed.

I knew I wanted to add a speed reduction between the motor and the saw input shaft. I went looking around for options and thought about pulleys and counter shafts. In the end, I decided to use a worm-gear speed reducer that I had picked up many years ago for another project that never happened. (I was thinking about building a dividing head loosely based on the Gingery design; but that project took so long to start that I ended up buying one in the mean-time).






I forgot to put a scale in the picture (again!), but the body that thing is about 5" wide, 6" tall and 3" thick.
The input shaft is 5/8" and the output shaft is 1". Both shafts have key ways.
That worm gear has likely been sitting in a box on the shelf for 15 years....time to put it to use.

Next I needed a coupler between the motor output shaft and the worm-gear input shaft.
The motor output shaft is threaded M14-2.0 on the end, but with a long 16mm shoulder.

I thought a Lovejoy coupling was what I wanted, they will put up with some misalignment.
However, I knew the local hardware store wouldn't have anything....and I also could not walk into the nearest most likely place to carry one (a fastener supply place in Ottawa) due to the pandemic lock-downs.....so I started to think about building one......

Once I got the idea of using a hockey puck, I just had to make one.
I cut two pieces of 1/4" steel plate, and turned some bushings to weld on.....and got this:

the motor (input) end:


the output end:


Those photos above were taken before the pins/tines were welded in......




A hockey-puck based homemade Lovejoy-type coupler!

Here's a test fit in the saw:



That is the band-saw input pulley at the top of the photo.

I welded a base onto those odd-shaped motor mounts and bolted both to a rusty piece of channel.

Here's a motor test:
View attachment motor_and_worm.mp4

Sorry about all the loose bits on the bench rattling around.

Getting closer........

-brino

 

[brino]

Next I needed a pulley for the worm-gear output shaft to drive a v-belt to the band-saw input pulley.
I've never cut a v-belt pulley before, but here we go......

I found a lump of ugly steel that I thought had a pulley hiding inside.....

it's about 3" diameter. I really just needed something that would have enough meat left after I cut the v-belt groove and the 1" centre hole.

I did find a pulley in there:



the entire V was cut with a parting tool, first as a deep groove, then with the compound set over to each side to nibble away the corners.
I did get some chatter in the bottom.

Cutting the key-way went better than expected. I was worried about cutting such a long keyway but after I made some new longer shims for the broach it went great. The broach bushing was about the same length as the pulley...

Don't you love it when the broaching goes properly:


That's from the 1/4" broach for the pulley.....last week I broke my 3/16" broach for the hockey puck coupler....the press jammed at one side and went at an angle.

-brino

 

[Janderso]

Nice save. That pulley is awesome.

 

[C-Bag]

Sux about your 3/16” broach. You know there’s so much I don’t know until it comes up to be done and until you mentioned cutting that pulley I hadn’t really thought it through. I wouldn‘t have thought a parting tool would work at an angle to do the side of the V. Mine don’t want to work that great cutting straight in.

 

[brino]

Hi Tony,

Sux about your 3/16” broach.

My broach kit is a cheaper import set originally bought at Busy-Bee tools. The job I was doing at the time paid for the kit.
I was going to provide a link, but it looks like they are selling less tooling now. :^(

I have replaced the 3/16" broach with another import one from KBC tools.

You know there’s so much I don’t know until it comes up to be done and until you mentioned cutting that pulley I hadn’t really thought it through. I wouldn‘t have thought a parting tool would work at an angle to do the side of the V. Mine don’t want to work that great cutting straight in.

I am sure there's a proper way to do it......I just followed what seemed right to me and what worked.

I had to look up the angle for the V, I used 38 degree included angle, so 19 degrees per side.
I faced one end, and drilled for and added the live centre.
I then cleaned-up the OD for the length of the part.
I used layout fluid and then marked four lines around the part from the freshly faced end; two for the bottom corners of the V and two for the tops of the V.
I cut a groove between the two centre lines to full depth of the V. This was wide enough to get calipers in to measure when to stop.

I tipped the compound to 19 degrees one side and still using the parting tool carefully tested nibbling off the corner.
That went well, so I just kept at it.
I was pleased to see that by the time the angle cut reached the flat bottom of the V that I was right on top of the layout line for the tops of the V.
I swung to the other side and repeated.

I test fit it with a belt I had on hand and made another shallow depth, slower-feed clean-up pass on the sides of the V.

I included a photo of my white-board sketch below.

I then removed the live centre support, and drilled and bored the 1" hole for the shaft.

I often do start parting on the lathe to define the end of the part and then take it to the band-saw to finish.
Here however, the parting tool was working so nice I parted the pulley off the stock fully in the lathe.
Note that I only needed about 1" of stick-out on the parting tool due to the centre bore.

You are right, I would NOT initially think of (or recommend) a parting blade for angled cuts, but when I tried it work well with no chatter.
There was also NO large feed pressures or any hint of the parting blade trying to bend or pull side-ways.
Be assured, if in looked, felt or sounded nasty I would have gone a different route.
I wish I knew what the steel was. It cut so beautifully I'd like to get more......

-brino

 

[C-Bag]

Thanks for running through your process for me Brino. I have so many shop made HSS lathe bits I bought in a garage sale I probably would have looked through them to see if I could find something that would have done the job. Probably started center cut with my parting tools like you did then gone to the custom bits. They have proven to be super handy and instructive as some of my favorites are not commonly seen in a book. Same with what came on my old shaper.

My broach kit I bought from Shars several years ago on sale and has proven to be able to do the jobs. Broaching the 4” long cast iron press body 3/8” I did was a job. The broach bushing I made in two pieces out of 12L14. Since reading about 12L14 here on H-M I’ve been making everything that doesn’t need to be special out of it because it machines so nice. I wonder if the chunk old steel you made your pulley out of was 12L14?

 

[Winegrower]

Great job, Brino! And a nice write up too.
I would like to do something like this and I envy an inventory of components like you had.
Your flex coupler is dang cool!

 

[FOMOGO]

Nice job Brino, could have easily been all pucked up by a lesser man. Any idea on your final speed range? Cheers, Mike

 

[brino]

I wonder if the chunk old steel you made your pulley out of was 12L14?

I was wondering the same based on recommendations here.
Thanks !

-brino

 

[brino]

Any idea on your final speed range?

Sorry for the delay, I needed some time to dig out the laser-tachometer and check both ends of my speed range.
Here's what I currently see:



The low-end 5 sfpm sounds too low to be useful......I may tweak the resistors on either side of the potentiometer to move the low-end up.

The high-end 137 sfpm should be great for me. I know most of the manuals (including Machinery Handbook and Starrett reference guide) show many blade speeds up around 200-300 sfpm and up to 400 sfpm for aluminum, but those are typically with coolant.

Now I just gotta find the shop time to get the motor mounted.

-brino