Setting stroke on Douglas Shaper

[Shawn]

I recently posted about having bought a Douglas shaper but wanted to make a new post with the title so it's easier to search for any other members who might be having the same head scratcher as me. On the SB shaper I own the length of the stroke is set against a scale engraved right on the scotch yoke. It's a simple affair to set the stroke for anything from 1" to 7" with the scale. The Ram starting and stopping points is set with a locking lever on top of the ram, again simple enough.

With the Douglas Shaper their is a scale but it is a brass plaque that is mounted on top of the dovetail on the main casting. In some photo's of various Douglas Shapers I have seen an indicator attached to the locking lever for the Ram position. I can't for the life of me see how this scale is to be used for setting stroke length? I'm sure there is a system but I can't figure it out. Just to clarify, I can change the lenght of the ram stroke but I'm kinda guessing as I go. Shapers are slow enough without having to wait for it to cut 20% air.

Here is a photo I borrowed from Tony's site showing a Douglas shaper with the red indicator arm hanging down from Ram position clamp.



Thanks for the help
Shawn

[dallen]

you have a photo of the yoke inside the door, Darren may be able to shed some light on this for you.

DA

[Shawn]

I borrowed this photo from Mayhem's post about his Douglas Shaper but the guts of mine look identical.



After looking at the photo I'm starting to wonder if loosening the ram and pushing it as far back as it would go while the yoke was horizontal like it is in the photo, maybe that indicator bar would make sense? seems like a rather involved way of setting the stroke lenght though.

Thanks
Shawn

[f350ca]

Shawn, I think my Logan is set up the same. You hand crank it to the maximum forward of the stroke. The reading off that pointer is your stroke length. On the logan you unlock a nut on the crank pin and pull or push the ram to the stroke length you want. (at maximum forward stroke the slot the crank pin runs in is horizontal). Lock the crank pin, then unlock the lever on top of the ram and position your stroke.
Hope that makes some sense.

[dallen]

I think Greg has it figured out,

DA

[Mayhem]

I was hoping to find the answer here, as I'm as lost as Shawn is on this one! I must admit, with everything else that has been going on, I've not actually had time to play with the shaper since I last posted about it.

[Shawn]

Thanks Greg, that sorted it out. The Douglas needs to be at the back of the stroke for setting the stroke length. At that point the scotch yoke forms a T and the pointer shows the stroke length that is set, loosen the bolt and slide the ram to adjust. I knew there had to be a simpler way than what I was doing.

Cheers Guys
Shawn

[Shawn]

Ok here's another question. Looking at the photo of the scotch yoke on Mayhems shaper and the one on mine there is a significant difference in the length of the dovetail that is attached to the large gear. I don't understand the point of having it longer than half the diameter of the gear?

I'll stop with the questions for tonight : )

Shawn

[Shawn]

So the new switch is wired up and everything is working. I was having some issue with the mechanism that drives the auto advance for the table being loose and much louder than I thought it should be. That was a simple fix though as someone had installed the taper pin in backwards. I cleaned the pin up and turned it around in the hole. My next issue I'd the sliding brass block that drives the yoke is quite undersized and does not return or advance the stroke without a gentle clank. Its probably 10 thou under sized on both side. My first thought is to use the original block which is taller than it is wide and cut it down for a 1-2 thou clearance fit. There wouldn't be as much surface area pushing against the drive arm but at least it will be tighter. Any thoughts on doing this? I figured if it didn't work I could always start from scratch with a proper sized piece of stock, just have to find one.



The sound in the video doesn't seem to be times right with the movement but I can see and feel the backlash in the sliding block. The ram stops at the end of the stroke then clunks as it get pulled back. It  does the same on the forward stroke. Any thoughts? Does my suggestion of turning the block clockwise 45 degrees and machining it down on two sides for a tight fit seem feasible? I'll try and stop at the scrap dealer tomorrow and see if he has some brass that might work as well. 








Cheers, thanks for looking
Shawn

[dallen]

make a new one from some NiBrAl, stuffs tougher then some steels and made to wear. how big is the block that's in there now 1.5 X
1.5 X 3/4 inches or somewhere around that.

The one in my Cincinatti does the same thing but its made from Cast Iron is is about 3 inches square and 4 long.

Myself I wouldn't mess with the original one, but that's just me.

DA