update on my fp7a + f7b project. Some months ago I completed the FP7A shell and mated it to a GP chassis. I wanted to add a F7B unit to the A unit so sourced a GP chassis and some parts I needed and finally over this Thanksgiving Weekend here in Canada I completed the modification to the GP chassis to shorten it to the length of an F unit chassis. Using the same method as David K Smith on his MP15 project, but I shortened only one end of the GP chassis to get an F unit chassis length I needed with GP power. I removed the small fly wheel and then drilled out the long end of the worm gear axle shaft with a #69 drill and then used a reamer to get a tapered fit to the ceramic shaft. And then press fit the worm to the shaft. This is delicate work as the ceramic shafts are very fragile. (I understand from Loren that current motors in used in production now have metal shafts) For removing the small fly wheel I used the NWSL box section wheel and gear puller but substituted a piece of brass "U" channel with a slot for the ceramic shaft for the plate to push against and used a custom pin made from a dentist dental reamer fitted into the end of the screw in the puller. In the pictures you can see the section I removed and the reconnection using a 00-90 screw down from the top of the chassis under the PCB with the lights. I made my cuts in such a manner that I left the retension post for the PCB in place. In the alignment process I used a shim of .040 inch styrene custom cut to fit the complete chassis when fully assembled. I screwed the two main chassis pieces in place, then screwed the two nose pieces to-gether and lid them onto the shim and aligned them up properly. I used a small piece of the .040 shim stock forward of the nose spacer to provide leverage to close the nose piece on the styrene shim. Otherwise it won't tighten up and stay in place for the next step. Once I had the nose piece aligned using steel straight edges I then put a drop of ACC in each cut line to hold the pieces in place and fill the gaps. Even cutting with the finest saw blades there is some loss of material in the cut. After a few minutes I repeated the process of filling the gaps with ACC. After letting it sit for half an hour I started the drilling process to provide the electrical connection between the two halves of the chassis. Without the screws you would only have power pickup from one truck not both as the ACC glue provides an insulator in the gap between the nose and the main chassis pieces. Once I had completed installing the screws I then used my excel scroll saw to cut the clearance from the fuel tank area to clear the front truck and used a file to clean up the cuts. A word of caution when drilling and tapping the 00-90 screw. If you go down exactly centered in the square lug on the main chassis you will come out of the side wall of the chassis in the area where the rear worm gear shaft bearing was located. This in itself is not a problem as you won't be using that bearing, but requires caution when drilling and tapping as this sort of location for te end of the hole can lead to breakage of the drill bit or later the tap. So you could really bugger the project if it happens. I used safe tap fluid for both drilling the holes and running the tap into the hole. I also back and clear the drill bit and the tap several times in the process. The screw I used was the one from MTL that we use for body mount couplers as they are the right length. The FP7A has a full pilot and body mount for 905 and I have filled in the lower head light as this soon to be CP engine only had the upper light. In the picture of the two units coupled to-gether you can see some of the pieces removed in the process of shortening the B unit chassis So the project continues.
Hi Dom; Sort of waiting to see what CP paint scheme we get the passenger cars in, but I think the older maroon and grey with script Canadian Pacific.
What all special tools do you need to shorten the frame Garth? I want to make a list of what I need to purchase to be able to shorten GP35 frames for F7 use. So far i got: NWSL Gear Puller to pull the flywheel What did you cut the frame with?
Rob, a Jewelers saw (like a Coping saw) or anything with a thinner blade. If you are taking out more that 1/16 inch, I would think and ordinary hacksaw blade would be fine, especially since the blade is much wider (depth of cut) that the Coping or Jeweler's saws which could have more skew. But once their out, a Mill would be nice to face them flat and square. Someone had several AZL FP45's on ebay last night for $156. Their's another workable chassis. Auction is over.
Tools for the GP to F chassis conversion I used an Excel scroll or Excel saw frame found at most hobby stores with their finest wire blade and you may need several to do this job. pin vise (2) one for taps and one for small numbered drill bits. NWSL "The Puller" 45-4 with custom ground push pin standard dentist reamer with head removed and shank ground down with dremel tool and cut off disc. I set the dremel tool in a vise and set it spinning and the put dentist reamer in another dremel and set it spinning and then held the turning dental reamer shank slightly above parallel with spinning disc and let it grind away until my digital caliper said the point was small enough to push the ceramic shaft of the motor out of the flywheel/coupling. The reason for only using the shank of the dental reamer is that the formed head while sharp is brittle and will shatter under a comperssion load while the stainless tool steel shank won't shear under comperssion . The other end of the dental reamer fits into the end of the screw in the NWSL puller screw. Two small files one flat and the other half round jewellers type hand file .040 styrene shim stock to use as a spacer when working on joining the two section of the chassis. #drill bits 68 69 and tap drill for 00-90 and a counter sink or use any drill bit that is a bit wider than the head of your screw. tap for 00-90 and it would be nice if you had a starter tap and a bottom tap for this job. Safe tap lubricant to drilling and taping. piece of brass angle wide enough to go around the flywheel coupling you are going to pull.
I tapped the shaft out of a MT flywheel by using a 1mm (or whatever size the MT shaft is) broken drill bit. I made a plate with a slot in it to support the flywheel and used a small jewelers hammer. Just another way to do it.
The cuts I made were first horizontal level with the top of the nose back under what will become the pads left on the original part of the chassis. The next cut was made with the chassis on its side with the retention post for the PCB down on the bottom at your work surface and make the cut down the face of tab as if you were going to cut the retention post off. However when I get down to the retention post for the PCB stopping short of cutting the post off. Then I turned the chassis upside down and using the partial cut finish the cut down to the bottom of the retention post and the nose piece should come free. The third cut was from the bottom just forward of the slot for the motor spring towards the end of cut number one. Here I cut a bit wide and dressed both the nose and the cut number 3 for a good flat match with a jeweler's file. Checking for the right truck center distance. When you assemble the nose to the existing chassis under the tabs line up the bottom of the nose piece with the bottom of the rest of the chassis and I used .040 inch styrene stock to make a piece to go between the two halves of the main chassis with a section sticking out where the nose is the go. I then put a small piece of the .040 material in the gap ahead of the chassis screw so when tightened on the piece in the main part of the chassis it clamps on it and will hold the alignment. You want as tight a fit as you can get down the length of the chassis. There will be a small gap between the pad on the main chassis and the end of the nose piece below it. I just used ACC to fill that gap but did not put in so much it attached itself to the >040 material once the glue set up I remove the .040 material and filled the cut gaps alround. Now your are ready to drill and tap for the screw going through the pad into the nose. Once this is done then a do the cuts for clearing the back of the truck in the new nose.
Just like most of train folks, I don't run clean, shiny car and this is my next project. It made from Robert's Woodchip car kit he released last couple of months. This is a " make over "car. Hien.
I'll have to talk to Mike but what trucks did you use and what did you use to connect the trucks and articulators? Thanks, Dave
Dave, the trucks are held by the same bolsters in the car. The car is milled using a dremel motor. The bottom of the articulated joint has a rod, and the top part has a hole. The trucks on the end are truck mounted coupler, but the ones on the joint, the trucks used are the ones used on a body mounted coupler.
From the '60's to the '90's My Truckee Layout has gone from the early 1960's now to the early 1990's with a few additions and some time to finally weather things up. Bill Mock Ummm, pardon the shifted pipe load. It looks like that Local Manifest will be sitting idle for a while.
Bill: This is about the most realistic scenery I have seen in a long time...especially the weedy open field area. NICE WORK. ...don
Hien, great re-work of Rob's kit. You have all the real world inspiration just 3 blocks away from the tracks ! .
Wow! I just LOVE that "red pipe" load! Wow! Does that thing speak volumes!!! Most Excellent! Hobo Tim :we-biggrin:
