Started on the cylinder block. I didn't have any 1-1/2" X 4" flat bar so decided to make it out of two pieces of 3/4" X 4" rather than order from the States.
I have just used the aluminium in the past for the cylinder but this time with the split block I decided to make cast iron liners for the cylinders. The initial plan was to have threaded caps on the ends of the cylinders to clamp them into the cylinder block as in the PDF Cross Twin 3a.
Good thing the planning was being done by the Mexican pool with a beer because the second version would just use brass plates on each end of the block to hold the liners in place. Much easier than threading!
Started by milling to two halves of the cylinder block in preparation for bolting them together.
Block halves now bolted together and ready to start the boring of the cylinders.
Cylinder block ready for the cast iron liners and then the retaining plates.
Cast iron sleeve liners cut from 1-1/2" bar. First time I have tried using liners in the cylinders. Got the cast bar from McMaster-Carr.
Nice stuff to machine but man was it dirty! That stuff gets everywhere!
I have hones on order to finish the inner surface of the sleeves.
Well the hones arrived this morning. I have to say that, for Canada, I am getting to like KBC almost as much as McMaster-Carr. They have a great selection of products and two day delivery to the door for a lot less than McMaster.
The two hones and some lathe tools arrived for $8 instead of the $40-50 from McMaster.
I ordered two hones, one at 120 grit and one at 240.
The cylinders are 1.100" and the 1-1/8" hones worked fine.
That's it for the cylinder block for now. Next will be the bearing blocks for the crankshaft.
Should be straight forward and a little rotary table work at the end to finish the top of the blocks.
Completed the bearing blocks for the crank. The crank will be 3/8 so I used a pair of 3/8 X 9?16 X 1/2 needle bearings.
Squaring up the 1/2" stock for the two blocks.
Drilled and reamed to 9/16 for the bearings.
Needed to use the rotary table for the tops of the two blocks.
At one point in the past I made a taper fitting for the centre of the RT that will accept a 3/8 pin.
The centre pin makes set up of the bearing straight forward. I now have a set of pins that step up or down from the 3/8 in the taper plug.
Used the side of the block to set up square at the 0 degree point.
I had to get an extended length mill from KBC to reach all the way through the 1/2" material. Decided on double ended and ordered two to cover my uncertainty milling with a 1/8 cutter 1/2" deep.
Turned out that I didn't need the three extra cutting surfaces - the first one lasted and I didn't break it!
Plunge cut in and around the 90 degree arc and out the other side and then did a cleanup climb milling pass to take off the last 5 thou.
Your mention of Crossheads puts me in an uncomfortable state, not you but my memory. I had a 9" diameter, #156 cast iron crosshead in a lathe, to turn the OD. got done, put the sling on the jib boom around the cross head, took out the center bolt, and the crosshead fell between the ways into the chip pan, taking my right hand with it. Mashed hell out of the first two fingers, end joint only. I spent a month on light duty, taking inventory. This had to be 30 years ago and it still makes my knees weak.
Started the Cross Head guides the other day by starting on the spacers required under and between the guides.
Soon ran into problems keeping all of the spacers the same length using my long spindle stop.
Took a deviation from the Cross Head to make up a 5C Collet stop shown in one of the other posts.
Much better results with the stop in the collet.
With the eight spacers completed, I could move on to the actual guides.
Started with 0.25" Aluminium flat brought to dimension and then just skimmed to flatten the faces. Unfortunately that then meant go back and do the spacers again as the guides were now no longer 0.25" thick.
Made new spacers to accommodate the very slightly thinner plate.
Started with the centre cutout. Every time I do this kind of cutout in the middle of a piece, I thank Tom Griffin for the hints on plunge milling instead of using the side of the cutter to do the bulk of the metal removal.
Cut the 1/2" wide tracks with a 7/16" mill. Ran down the centre line first and the stepped over to each side and climb milled the finished edge and the last 3 thou of the depth.
Slots came out nice.
Drilled the four corner holes to finish each guide.
Started on the crankshaft.
You can tell that hobbyists (at least me) have a low value of time! I needed a piece of 5/8" flat to make the web of the crank shaft.
All I had was a piece of 1" flat, 6" wide. So cut it roughly with the 4X6 and then start milling!
Eventually got it to size. NEXT TIME GO BUY A NEW PIECE OF MATERIAL!!!
Done and ready to start drilling the three shaft holes.
Decided the best way to ensure alignment of the three pieces of the web was to drill in one piece and then cut it apart for the three pieces.
Drilling and reaming for the 3/8" shafts.
Nice slip fit on the 3/8 drill rod used for the shafts.
Didn't try to do a shrink fit as they will be Loctite glued and pinned with spring pins at each joint.
Cut the first side piece off the main block. Notice that to preserve registration among the holes, they were marked to maintain the same orientations.
As a result of the saw cut, I now have one machined face on the TL side and a saw cut face. Before cutting the second side off, the saw cut face on the main block had to be machined to allow me to keep the square orientation of the holes in the main block. After milling the cut face it was returned to the saw to remove the other side piece.
Re-milling the centre block to keep the face square to the holes.
Cutting the second end piece off the main block. Had to set up blocking to clamp the short piece in the saw!
Milled both end pieces to keep the same thickness. (and save some time!)
Three blocks completed and ready for trial fitting. Note that I did manage to hold the orientation the same. (Major win!)
Trial fit with the three shafts.
The centre block will now have to be cut down to the angled connector.
Angle cuts laid out on the centre block. The block was set in the vise using a 1/8 parallel laying flat on the jaw to align with the scribed line.
The second cut is done with the initial cut face on a parallel.
Ready to start the assembly. All parts will be washed in acetone and then the two small shafts will be glued to the end webs using Red Loctite. They were left over night to harden before using the adhesive on the centre web.
Crankshaft all glued together. It will sit overnight before trying the drilling and reaming for spring pins at each of the seven joints.
Exactly Terry. I have built a number of his designs.
Lately I have started using his design as a start and redrawing, modifying and figuring out how to make.
Gives something for an activity while hiding from Canada's winter down south.
Turning a crank from solid turned out to be a little more tasking than I had originally imagined.
Started with the idea of using a parting tool to cut the slots for the two journals.
Started making up the blank from some hot rolled flat bar.
Face milled down to 5/8 inch.
Centre drilled each end for the three rotational axes.
Cutting the first journal.
Got part way and decided that this was a very scary way to make these slots. That blade is sticking out a long way.
About two seconds after that thought, the edge of the blade caught the blank and everything went to hell in a handbasket.
Time to re-think and start over.
Decided that a new tool was in order. I purchased some rectangular tools 1/4 X 3/8 and 1/4 X 1/2
Ground two ends of one of the 1/4 X 3/8 tools to be what was essentially heavy parting tool ends.
One end to cut left and the other right. I put about a 1.5 degree angle on the face of the tool with the idea that the actual journal could be finished by cutting from the centre to each side.
Finished side view of the double ended tool.
Also thought that bandsawing the blank ahead of turning would help the cause.
Sawed out the first journal area and then started on the other before thinking that it would flex.
Made up a spacer to eliminate the width of the saw cuts.
Started cutting with the new tools. Cut very well down the sides of the slot.
Getting near the dimention for the journal and the wide tool dug in and the blank lasted not at all!
Decided that the wide end to the tools could be improved on so ground the ends to leave just a small (1/16") flat on the face.
Again bandsawed out the journal space to get started. No additional saw cuts this time!
Everything was going well for the first little bit. Got the slot cut to the proper dimension, leaving the journal at 0.625" and then started reducing it to the target 0.375" finished dimension.
Just a little in-attention and there went another blank after about another two hours of work. Getting somewhat frustrated with this stupid idea of cutting cranks from solid pieces. This time it tore up the dog and the centre in the headstock.
Starting again on the first journal slot.
Cutting the sides is getting to be routine now.
Switched back to a 1/4" flat nosed tool to finish the journal to the final 0.375" dimension.
To avoid it digging into the job, I put the lathe out of gear and turned the spindle by hand. The freshly sharpened tool would shave off less than a thou at a time, leaving a nice finish.
Made up an aluminium spacer for the first journal slot and started on the second.
Finishing off the final dimension of the second.
Now, just need a second spacer and I can get started on the centre shafts.
That is a very cool project!... But what I really appreciate is your photos of the machining in action! As a complete novice I am learning a lot from your posts and seeing how you are setting things up and how you are doing the machining. And the blank that got ruined... very cool that you shared that! There always seems to be more to learn from something that went awry then when everything works out perfectly the first time.