Hi everyone,
This is a project that Maury (Lone Star Engine Works) and I have been working on for a while now and we finally have enough progress we are able to share it with you. This pump is being scaled and modeled using an original magazine advertisement from 1892 that I purchased off eBay a number of years ago.
The Pump and drive components have been modeled in Solid Works and the all the patterns are being made using CNC milling machines. I have the 3d models mostly complete and Maury has been taking my models and doing the necessary operations to turn them into patterns, adding machining allowance, draft, core prints, and scaling for shrinkage. We both have been making patterns and core boxes. Maury will take the individual pattern that we have made and make mold boxes for them and get them ready for the foundry.
My shop time isn’t always what I would like it to be so I haven’t been able to contribute as much on as I had hoped to. I have been able to make the base pattern and core box and Maury has done the rest of the pieces.
I going to show some of the work I have completed to date and Maury hopefully is also going to add to the thread and show some of his awesome pattern making and foundry skills.
And in case you have missed it here is a link to my build thread on the Pacific vapor engine the will be running the Goulds pump.
http://www.modelenginemaker.com/index.php?topic=1326.0
Here is a scan of the original advertisement the was the starting point for this project
After many hours of modeling and some head scratching here is mostly finished 3d assembly. I still have a few details to add.
My brother who is an Auto CAD master was a huge help, he took a scanned image from the original add and scaled it to match my engine (as well as he could) then created top, front and side views of the pump. I used these 2d drawings as a base to create the 3d model in Solid Works. Without his help I’m not sure I could have done it.
This a part of a screen shot from AutoCAD showing some of his line work, that allowed us to be able to pull measurements of the pump parts. The problem was this is not a true isometric drawing and the engine is really stretched out of proportion relative to the model, mostly in the vertical axis. By using known dimensions of my model and transferring them to the drawing he created scale factors, so depending on where vertically on the pump a measurement was taken it could be corrected to take care of the scaling issues. I feel he hit it pretty close.
Once the CAD models were getting close I printed one to see how it would look alongside the engine. I was happy with the proportions of the assembly.
Just for grins I decided to give the printed model a coat of cast iron gray paint and add some hardware.
Starting work on the base pattern; here is the first roughing operation of the base. The material is high density polyurethane modeling board.
.200” depth of cut and .05” step over gets the bulk of the material out of the way in short order.
Then using a 1/8” carbide ball end mill the base is surfaced using .002” step over. Then a 1/16” ball end mill was used to go in and create some of the small fillets around the bosses.
I had decided to make the base pattern in two pieces then glue them together. Here the base has been flipped over and the cavity where the core print will reside is being roughed out.
After the roughing operation it is surfaced using ¼” carbide .03” radius bull end mill.
The sharp corners were machined using a 1.5deg tapered end mill to match the draft angle of the core print.
A ½” ABS dowel was used to align the parts and core print part is glued in using 5 minute epoxy.
Here is the finished pattern ready for its trip to Maury’s shop in Texas.
Here is the second operation of the core box for the base. The core box has draft (the long sides) so the core can be removed and that was machined in on the first operation using a tapered end mill.
Here is the finished core box also ready to go on a trip.
That is pretty much all I have at this time. Maury is also going to add some pictures so we get to see more of his great work.
Thanks for checking in,
Dave
