I am in the process of taking 2 lifelike GP20 frames and installing them on some Atlas GP30 shells. The shells are not a snug fit but this looks do able. What would you recommend to fill in between the frame and the shell to make this a more snug fit? As is the shell easily lifts off .This is my first Nscale engine kitbash so I hope it works.If it does I just got 2 GP30 for about $60 that have pretty close to scale speed.
I can think of a couple of methods. I'm sure there are better ones. A) Use thin strips of sheet styrene to build-up the inside of the shell at the walkways. You can only get a more snug fit, as too much will spread the shell. B) I have not tried this, but I heard you can use small dabs of clear latex caulk at the front and rear. Lower the body shell into place and position. Let sit overnight until the caulk sets-up. Now you can pick the loco up by the body shell without it moving. If you need to remove it, just take a small knife or screwdriver and pry the caulk away. It just takes a long time to put the shell back on. Hope this helps.
Randy, The GP-20 wheelbase and the GP-30 are not exactly the same with the gp-20 being a tad shorter. Southern Digital makes a custom frame that allows you to use the liflike mechanism in an atlas GP30/35, they go for around $10. This may help solve the loose fit problem.
Thanks Mopac 1 and Andy for your help.Does Sourthern Digital have a web site I remember seeing a Ad for them somewhere?
May I suggest covering the frame with Suran Wrap and scotch tape it just over the wheels, to stay in place. Wash the shell to remove any oil, finger prints, and dirt, then dry it. (You may wish to use tooth pics to center the shell around the frame before the caulk sets up). Now when you apply clear latex caulk, it will stick to the shell, form around the frame as needed, but not stick to the frame. Try a drop on the Suran first! If the brand of caulk you want to use does stick to the Suran, you will know to unwrap the frame before separating the shell and frame. I have never had any of the latexes or silicones stick to Suran Wrap, but I have heard that someone used something that did stick to it, so test it. Carefully cut the scotch tape and slip the frame out of the shell, leaving the Suran in place for now. Put the frame aside out of the way. Gently pull the Suran Wrap loose from the latex caulk [BUT] (there are a couple of brands that may stick to the Suran also). Those you must cut around the caulk and leave the Suran on the caulk, it wont matter. It is a good idea to dust the caulk with a face powder or Talcum powder, to "kill" the rubbery surface of the caulk so it can slip. Either way, you may easily lift the shell off when needed, and will easily slip back on. It is maybe better to drill two holes to mount the shell with screws, than depend on lifting the whole engine with just the shell. Sometimes the frame comes loose even on the snap on type, letting the frame/motor fall to the floor. (This happened at a hobby shop!) By bonding small blocks of plastic inside the shell in out of the way places so they sit on the frame, and marking the frame, it is rather easy to drill a TAP SIZE hole all the way through the frame and block at the same time, then run your tap through both frame and block to attain absolute accuracy of alignment. THEN, separate the shell and frame, and drill the BODY size hole through the frame. When shell and frame are re-assembled, the holes will always be perfectly aligned, and the screws may be tightened just snug enough to hold in place, yet be removed at will. [ 04 September 2001: Message edited by: watash ]</p>
Good Luck Randy, Let me know how it turns out- I bought a couple GP-20's too with similar intentions of powering some Atlas GP-35 shells inexpensively and with the added bonus of the good running Lifelike mechanism. I too tried the fit and had the same problem of looseness, and the short wheel base just did't look quite right. I heard of the frames on the Atlas forum from a guy I think was John Heathman. Apparently the standard Southern digital frame kit for an Atlas GP-35/30 will work. John recommended adding a little length to the contact tabs, especially if going DCC. I am working on painting and detailing the GP-35 shells and will be trying the frames myself soon.
