Terry Harper

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About Terry Harper

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  • Birthday 11/13/1963

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  1. Terry Harper

    locomobile 38 bearings zinc or bronze?

    Bronze backed Babbitt would be my guess. which would leave you the option of making or re-using the existing bronze shells or omitting the shells and going with a traditional non-backed Babbitt bearing. Interestingly I have come across one motor that had inserts that were completely Babbitt (see photo) This was for a 1909? Jackson. They used dowels to locate the inserts. However, I very much doubt Locomobile would have gone that route.
  2. Terry Harper

    My 1910 Mitchell "parts car" project

    That looks great Joe! Makes me want to get back to finishing my manifold - the castings of which are collecting dust on the work bench.
  3. Terry Harper

    My 1910 Mitchell "parts car" project

    Hello Joe, On your vane pump could you use a simple spring loaded bypass valve? Here is the drawing for the service pump for the Wisconsin. This is the lower half or service pump and the gears. Of importance is the passage on the upper right tapped 7/8-18 for a adjustable spring loaded plunger (note the offset cross-passages). When the pressure exceeds the set amount it forces the plunger back and allows the excess to bleed back into the pan. Its a very low pressure system (5-10 psi) more dependent on volume than velocity. While this looks like a complex piece it would be fairly easy to simplify and re-configure.
  4. Terry Harper

    3D Parts Printing

    3D printed metal parts are feasible and have been used from sometime in other hobbies such as the Live Steam hobby and some industries - I believe awhile ago one manufacturer received certification to 3D print certain parts for use in turbine engines. However, as pointed out it has to start with an accurate 3D model. I teach CAD and in particular we work extensively with parametric modeling and additive manufacturing and CNC technologies. The printing is the easy part! Its modeling the component and determining tolerances and fit that takes a lot of time which adds up to a lot of cost if your paying someone else to do it. Fortunately 3D scanning technology is available and works wonders when applied to reverse engineering and quality control. Recently I had a part scanned at the University Of Maine Advanced Manufacturing facility. Could I have it 3D printed in metal? yes. but the size of the print would make the cost prohibitive. The plan is to use the resulting 3D model to develop 3D printed/CNC patterns and core boxes and then use traditional foundry work to cast the finished part. It may sound more complex than printing the part but its more cost effective since with the exception of the foundry work I can do most of it myself. Here is a video: Here is a project we developed a few month ago and gives you a good idea of the work flow: Using patent drawings and measurements from original parts we reverse engineered a proprietary magneto coupling used on early Wisconsin engines (the big T-head watercooled models) Once the digital 3D model was created using Autodesk Inventor Professional, the shop drawings were developed and a mockup was 3D printed. The digital 3D model was than copied and modified to including such features as draft, shrinkage and machining allowance. We could have 3D printed the patterns but we chose to mill them out on the CNC mill so the completed files were imported into Fusion 360 where we added tool paths etc. than exported as G-Code to PathPilot which is the operating system for our CNC mill. Next its off to the foundry and then to be machined.
  5. Terry Harper

    My 1910 Mitchell "parts car" project

    Hello Joe, We all have varying degrees of "good enough" Some people are satisfied doing the least amount possible - others - like you, (and me to a more limited extent) have to do the job to the uppermost limit of their experience and skills sets. For some of us that challenge if you will and need to achieve perccision results is all part of the fun and satisfaction. For example I have a friend who has been building an experimental aircraft for the past seven years. Achieving a phenomenal level of craftsmanship and the act of building is a passion for him that trumps the actually flying! In the pragmatic approach are you really gaining any value by going the extra bit in this instance? Probably not. But, you are building a new manifold which is the perfect time to go just that extra bit more to correct a fault. The stud - yes - but I don't think I would worry to much about the ports being out of round. In fact, I am think about the same approach - plug the offending hole and drill a new one. Alan, I am not sure. You would think that each jug was gang bored using a fixture so they would be all the same. I do know that at some point they changed from a elaborate cast aluminum manifold to the assembled brass.
  6. Terry Harper

    My 1910 Mitchell "parts car" project

    Joe, I think that's rather typical. On my big Wisconsin, which is supposed to be high quality, one of the studs for the intake manifold on the middle cylinder block is way offset from the centerline of the port as well. The funny thing is almost every one of the PT series engines I have examined has the same issue - all the intake manifolds have the same hole enlarged and offset yet each of the blocks is supposed to be interchangeable.
  7. Terry Harper

    Speedster Builds.............

    Alan, I spoke to Don today. He's waiting for winter to end just like me! At this point a little global warming would be most welcome! In regards to the valve shrouds - As Don and I discussed, since there are some differences between the early and later engines I am going to 3d print 2 halves that I can ship out to you to try. I should have these on the way to you by the end of next week. Once we know that these will work Don can drop the patterns off at the foundry that's near him and get a price for you. T.
  8. Terry Harper

    1922 Elcar K6 Coupe Ultra Rare For Sale

    I am glad to see this survivor and I hope it goes to a good home. I have always been interested in Elcar - they produced some interesting and powerful automobiles for the time. This discussion reminds me of the Locomobile Junior 8 that was recently for sale. In the case of the Locomobile we had a wonderful survivor from a low volume, high quality prestige manufacturer and yet it took forever to move out of the low ball numbers. As with this Elcar would it ever be worth a big buck professional restoration? No but sensitively restored by a DIY type person and it would be both rewarding and unique. For a further discussion on Elcar: http://forums.aaca.org/topic/286100-elcar/
  9. Terry Harper

    My 1910 Mitchell "parts car" project

    Joe They sure made things more complicated than they needed too! Its like every pipe they decided just HAD to cross over to the other side of the block! I can't help in regards to the exhaust manifold other than if you were to cast it the pattern wouldn't be too difficult. You would need a follower to maintain the part line due to the inward angle at the down pipe connection. My beast is a different problem - The one piece manifold is interesting. It actually connected to a cone shaped blast pipe (similar to that used in a steam locomotive) projecting into a tin shroud/stack. You can see all the welds and repairs - that's from the expansion and contraction due to the distance between the blocks. The other pieces are the stacks that replaced it. The complete unit has a heater box attached. If I end-up with it in a speedster I thought about running three cast iron horizontal stacks with that neat rectangular profile out through the side of the hood but somehow I think people would have a problem with the side of their cars being blow torched (aka Beast of Turin!)
  10. Terry Harper

    1925 Locomobile Junior 8 For Sale

    Al, I keep looking at this Locomobile. In my mind its a fantastic survivor and would be worthy of a sensitive restoration (enhanced oily rag perhaps?) Would it be worth dropping big bucks for a professional restoration? No. But, it sure makes sense if your a skilled do-it-your-selfer. Alas, it will have to remain a dream for me. Hopefully it will find a good home.
  11. Terry Harper

    My 1910 Mitchell "parts car" project

    Hi Alan, On my Wisconsin PT the manifold is brass tubing. The OD IS 1-3/4" with a .065 wall thickness. Interestingly the pipe connecting the cylinders is all one piece with holes bored to correspond with the T-fitting for cylinders 3 & 4 and the t/elbows that connect to the lower pipe. The fittings are simply bored to diameter and slid onto the tube and soldered in place. Unfortunately I didn't know that until I got to look inside an original and got my hands on a factory drawing so my fittings are simply counter bored at each end and the pipe is short sections cut to fit. Fortunately once its all together no one will know the difference other than me!
  12. Terry Harper

    Speedster Builds.............

    Hello Alan, I have to get on his case too! He owes me two more sets of valve shrouds (Wisconsin model "A") and some water fittings as well! Typically he hibernates during the winter but I don't want him to forget! On the other hand his price is beyond fair so I don't like to push too hard! T.
  13. Terry Harper

    My 1910 Mitchell "parts car" project

    Joe, That is fantastic! There is a lot of time and wonderful craftsmanship represented there! Bravo!
  14. Terry Harper

    Speedster Builds.............

    Hello Alan, This is the setup I will be using. I have the castings for the brackets - just (as usual) need time to get at them! The brackets simply take the place of a screw in each of the cover plates. Its hidden by the hood but you can see the tube carrying the wires down to the magneto and a poor quality but overall view
  15. Terry Harper

    Manufacture part from CAD file?

    Very nice! On your 3D printed pattern - don't forget draft (slope to the vertical sides perpendicular to the direction of pull) this allows the pattern to be pulled easily from the sand. The typical angle is from 2-1/2 - 3 degrees from vertical. Also you will need to add allowance for machining. For example if you have a surface that needs to be milled or faced flat we would add 1/16" or more to the thickness to allow enough material to be removed that will allow removal of all imperfections without having the finished part end-up undersize after machining. A foundry that comes highly recommended is Cattail Foundry run by the King family in Pennsylvania. They are also very good at using original parts as the pattern.