Gerard's Shaper Design
#41
(11-21-2012, 11:09 PM)f350ca Wrote: Jason, post 19 shows the mechanism. i think its called a Scotch yoke. The slider can be adjusted out from center on the rotating disk to vary the stroke length. Neat mechanism, it cuts with the pin on the top half of the disk and returns faster with the pin on the bottom half.

Hello Greg,
In the interests of accuracy, I don't mean to offend by contradiction. The quick return shaper mechanism isn't really a scotch yoke, there are similarities with the sliding block running in a slotted component, but the big difference is that a scotch yokes number one claim to fame is it's perfectly even sinusoidal speed profile where both the return and forward strokes are the same, and the actual correct name for the shapers mechanism is the "Whitworth Patent, quick return shaper stroke" Catchy, isn't it?

In reply to another post, Yes the shaper is credited to James Nasmyth in 1836, however there are examples of shapers and planers that predate the Nasmyth version, and I believe that the Nasmyth didn't have the quick return mechanism which was applied to the shaper by that hero of machine tool designers Joseph Whitworth, who was a student of Nasmyth as well as Maudslay, My memory doesn't stretch to the Patent date of the QR mechanism. but it should be noted that the original QR mechanism didn't use the vertical/near vertical slotted link with the sliding block, but rather was less effective using only a crank disc and conrod that was mounted above the ram rather than in the column, the column style shaper like Gerrards, with the internal QR mechanism, came some time later, the earlier versions had a table that moved up and down but not sideways instead the ram complete with QR mechanism traversed sideways in order to cut plane surfaces.

This traversing ram style can often be seen when older hand shapers find themselves on EBay.

Best Regards
Rick
Whatever it is, do it today, Tomorrow may not be an option and regret outlasts fatigue.
Reply
Thanks given by: EdK
#42
Some more pictures of Gerard's shaper progress.

Ed

   

   

   

   

   
Reply
Thanks given by:
#43
Thanks Ed, any updates on Gerard himself?
sasquatch, proud to be a member of MetalworkingFun since Jul 2012.
Reply
Thanks given by:
#44
(03-01-2013, 07:10 PM)sasquatch Wrote: Thanks Ed, any updates on Gerard himself?

Yes, here.

http://www.metalworkingfun.com/showthrea...4#pid18694
Reply
Thanks given by:
#45
Thanks Ed, i did see that, was just hoping Gerard was not having health issues.
sasquatch, proud to be a member of MetalworkingFun since Jul 2012.
Reply
Thanks given by:
#46
(03-02-2013, 09:00 AM)sasquatch Wrote: Thanks Ed, i did see that, was just hoping Gerard was not having health issues.

I was concerned of that also but it's not so. He does a lot of volunteer work and has just been very busy with that.

Ed
Reply
Thanks given by:
#47
It's coming along nicely. Thumbsup
Smiley-eatdrink004
DaveH
Reply
Thanks given by:
#48
Hello Guys
Here I am back after a long time. The last three months we have completely renovated the bathroom and my garage so I had little time in my workshop to work on my shaper. On the pictures you can see I need to paint still the walls. I did not quite sit still and have the gearbox now fully ready. I was a little afraid to make the gearbox. I had no drawings or pictures so I had to draw and calculate everything from scatch. The gearbox works perfectly. The gear shifters work very smooth. I am very happy that everything went well. I also have made the base plate and the stand. Attached some pictures.
   
Gearbox in high speed position

   
Gearbox in low speed position

   
lower gear shifter

   

   
Machine stand

   
Base plate with in the middle the two holes for the table lift mechanism.
Reply
Thanks given by:
#49
Again very impressive work Girard, thanks for posting the great pics again. We were hoping you were just busy with other projects. The shaper looks just fine, nice work!!
sasquatch, proud to be a member of MetalworkingFun since Jul 2012.
Reply
Thanks given by:
#50
Gerard,

Thanks for posting the pictures. That tool is really turning out to be a piece of art. Thumbsup

Ed
Reply
Thanks given by:




Users browsing this thread: 3 Guest(s)