| Hofmann Engineering 1/3 scale Power Hacksaw Casting's Kit ___________________________________________ First Impression The castings looked good when I first looked at them , Then I got My wall casting kit and could not believe how much better Ron's castings are!! The iron castings are almost completely free of pin holes . The brass casting's are clean and beautyfully cast out of a very strong & pretty brass! The castings Machine great and finish to a smooth & shiny surface! The Only thing that I did not when I first looked through the kit , was the box & packing that it was shipped in . The box was too weak for the weight of the kit, and was split down two corners. The castings were wrapped in brown paper that had riped and almost shreded itself. But none of the castings were hurt or missing! ___________________________________________ Prints The prints are well drawn and clear .I did find a few small gliches in them , but nothing that could not be figured out . A couple things that I think could be improved on are : (1) The assembly drawings are to small and need more detail, Especially on the lift tower asimbly. (2) Also neaded is a list of bolts & nuts ,Listed by size and quanity. ___________________________________________ MACHINING ___________________________________________ Base Frame The base frame was very easy to machine! I set it ,and fly cut the top, then layedout all of the holes and marked what size they were to be drilled & taped , after the holes were all done I cut the "T" slot for the vise. __________________________________________ Main Slide Frame This Is a bit more complicated than the base frame! To start with I opened the dovetail slot up to size&depth. Then I layed out and drilled all of the holes that I could get to from this side. Then I cut the dovetails.Next I turned the casting over and drilled the holes on the back ,ans then set it on edge and drilled the holes in the top edge. _________________________________________ Sliding Blade Mount Frame This is probably the hardest part to machine , The setup is hard because of the shape of the casting! You nead to cut the slots for the blade holders , square up and machine the dovetailed section all in the same setup so that they will be true to eachother! One problem that I had was that after all parts were machined I realized that the rod would not clear the reinforcement web on the casting , and I had to braze the holes up and redrill them .125in lower on the casting. All other Work gave no problems . _________________________________________ Shafts All of the shafts are easy to make! I made the 3 steel shafts out of hard pins. _________________________________________ |
| Pully The pully was easy to machine and the casting ran VERRY true! I just machined it all over and then filed the crown on it. ___________________________________________ Lift Cam Very simple , Drill & bore shaft hole,drill & tap setscrew hole, then true up the cam shape on a belt,or disk sander! ___________________________________________ Lift Tower This is The hardest part to understand the print for , But if you study the print very carefully and fully understand it before you start to cut metal (I did not do this and had to ask Ron a few dumb qustions) It is easy to machine! _________________________________________ Crank Pin It is easy to make as it is drawn, but I made Mine easyer by drilling&taping the center of it and used a piece of allthred , instead of haveing to cut two sets of threds! __________________________________________ Main Bearing Block Allthough This looks complicated it is not! This is easy to machine . Just remember that on the 2.500 dim. between the two biggest holes , that this sets the backlash of the gears! I would use a tolerance of +.002 and -.000 ! Also the 1.000 hole should be machined .997-.998 and then laped or honed to fit the slidemount/crank gear shaft bushing!!! This fit neads to be VERRY close (like a ringless piston in its bore) _________________________________________ Slide Mount/Crank Gear Shaft Bushing This is an easy turning exercise ! Cut to 1.001 and polish to size! _______________________________________ Vise Screw Block I am shore Ron will fix this But the dimensions on the print nead to be reversed. the hights of .250 and .375 nead to be reversed to get the casting to be able to be machined ! _________________________________________ Vise Jaws/ Sliding & Fixed They are both easy to machine ! I put the sliding jaw in the "T" slot on the base , mounted the screw block and transfered the hole for the vise screw so that it would be shore to line up exactly! _____________________________________________ Sheet Metal Parts I AM NO GOOD AT SHEET METAL WORK!!!!!!! That being said : I was going to build my stand out of 1/2X1/2X1/16 angel iron and box tubing, But after Ron encourged me a lot I finaly bit the bullet and tryed to make them out of sheet metal . To my suprise they turned out good! The guards were easer to make than the stands and they turned out good also !! So if I can make them out of sheet metal then anybody can!!! ___________________________________________ All Other Parts All of the other parts Are Easy to machine and do not nead any discription or tips for makeing them! ___________________________________________ All In All This is a VERRY good kit ! I give It a 9.5 out of 10 and HIGHLY recomend it!!!! George Hunt Tool&Die Machinist Miniature Engineer If you have any qustions about this kit then email me at: huntfamgjc@yahoo.com contact Ron Hofmann at: hofmann_eng@msn.com |