Table-Top or Toolpost Shaper

Here's a "working" concept of a small shaper. The design goal is for it to work in the lathe via a toolholder in the toolpost or, on a small table-top fixture. The main use will be for cutting fairly small keyways in pulleys or gear bores. I'm also using this project to learn Fusion 360 after many years of Alibre CAD.

The design is based on the classic Whitworth "Quick Return" slider/shaper mechanism. This is the first time I've used a CAD program for all the conceptual diagrams. I did not use a pencil or notepad for hand sketches like I usually do. I used pencil/paper only for a handful of trig problems and also to calculate the position, torque and speed of the slider rod given the small gear motor that was selected for the project.

This diagram is no-where near what it will finally look like. This diagram only shows the mechanical model to prove-out the basic design. My design goal was to have a shaper that had an adjustable stroke up to 3.25". Fusion 360 has stress analysis and simulation abilities and this conceptual model was used to verify the range of motion and stress areas. The computer model actually "works", in that the motor shaft can be turned and all members move accordingly. It was a fun little project to learn Fusion 360.

For reference, in this model, the slider rod is 8.5" long. The block that holds the slider is theoretically pinned in this model as is the motor and the plate that the assembly is mounted on.
Shaper Concept.JPG

The gear motor will be here in a couple weeks along with a fresh supply of small bearings. I'll work on the model until I'm happy with the "final" design and then I'll build it. Most of the components you see are in their final form but, the enclosure, clapper box and self adjusting mechanism is not even started yet. That will be pretty cut-and-dry.

I'll post a few more pictures at various milestones as things progress.

Ray
 
I have a slotting attachment for my #2 Brown & Sharpe mill, it uses a simple adjustable stroke crank; for the tool you are planning, why over complicate it with the quick return motion? For the limited work it will be doing, it would likely not really save very much time in cutting.
 
I have a slotting attachment for my #2 Brown & Sharpe mill, it uses a simple adjustable stroke crank; for the tool you are planning, why over complicate it with the quick return motion? For the limited work it will be doing, it would likely not really save very much time in cutting.

The real goal was to learn Fusion 360. This project had the right mix of simplicity and complexity to learn a new CAD package. Aside from that, the Whitworth mechanism is a classic and historic mechanical design. I'll make a working/functioning model just for grins.

Ray
 
There are some old plans floating around on the interwebs of a very small shaper for mounting on the cross slide of a lathe. It uses a scotch yoke design, not a whitworth mechanism and had a fixed stroke. I can't find them right now, but the concept looked quite neet. I have a small gearmotor and some vague future plans to build one to mount on the lathe. I thought about using a milling attachment, such as the one sold in kit form by MLA to mount it on, giving it vertical movement as well. Looking forward to seeing how this turns out.
 
Here's a "working" concept of a small shaper. The design goal is for it to work in the lathe via a toolholder in the toolpost or, on a small table-top fixture. The main use will be for cutting fairly small keyways in pulleys or gear bores. I'm also using this project to learn Fusion 360 after many years of Alibre CAD.

The design is based on the classic Whitworth "Quick Return" slider/shaper mechanism. This is the first time I've used a CAD program for all the conceptual diagrams. I did not use a pencil or notepad for hand sketches like I usually do. I used pencil/paper only for a handful of trig problems and also to calculate the position, torque and speed of the slider rod given the small gear motor that was selected for the project.

This diagram is no-where near what it will finally look like. This diagram only shows the mechanical model to prove-out the basic design. My design goal was to have a shaper that had an adjustable stroke up to 3.25". Fusion 360 has stress analysis and simulation abilities and this conceptual model was used to verify the range of motion and stress areas. The computer model actually "works", in that the motor shaft can be turned and all members move accordingly. It was a fun little project to learn Fusion 360.

For reference, in this model, the slider rod is 8.5" long. The block that holds the slider is theoretically pinned in this model as is the motor and the plate that the assembly is mounted on.
View attachment 269933

The gear motor will be here in a couple weeks along with a fresh supply of small bearings. I'll work on the model until I'm happy with the "final" design and then I'll build it. Most of the components you see are in their final form but, the enclosure, clapper box and self adjusting mechanism is not even started yet. That will be pretty cut-and-dry.

I'll post a few more pictures at various milestones as things progress.

Ray
Absolutely very interesting I'm amazed that you can do that in the learning phase I'd like to learn Fusion 360, but I have no idea where to start, just looking at it scares me. I was over 40 before I new how to turn a computer on.
 
Great project Ray. I'm in for the ride.

I didn't know the Whitworth mechanism by name so looked for some animations. Below are two variants that show how it works.


 
Absolutely very interesting I'm amazed that you can do that in the learning phase I'd like to learn Fusion 360, but I have no idea where to start, just looking at it scares me. I was over 40 before I new how to turn a computer on.

Hi Bob, nice to hear from you again.

If you are comfortable enough with computers to use a word processor (such as Microsoft Word) to make drawings or presentation software (such as Microsoft PowerPoint) then, with a little practice, you can learn to use a CAD program. For Fusion 360, someone from this list recommended a YouTube instructor named Lars Christensen. He does about the best job of teaching to absolute beginners.

I had previous background first with SolidWorks then with Alibre CAD. When I was running my own consulting business, I purchased/used Alibre and many of the additional add-on packages. Learning the first one is a little tricky but after that, it's really not hard to learn others. In the past, I've taken a good handful of training courses and at times, paid hourly for 1:1 instruction to be able to complete certain tasks.

The point is, do not be discouraged because I was able to do this while learning Fusion 360. I had a good running start.

Whitworth Quick Return... An absolute classic mechanism that is typically used as a study case in the 3rd or 4th year of "traditional" mechanical engineering school. The mathematics that describe the motion is... well... really cool. Whitworth was educated but I don't know if he possessed the math background to accurately describe and predict the mechanism's motion. If he did, then he gets a gold star next to his A+. -Take that back... 2 gold stars.

Ray
 
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