LR3

This really is a multimedia model. There will be aluminum panels, RP pieces, a fiberglass body and resin parts for detail. The Madd Fabricator sent a batch of resin parts consisting of wheels front and back, brake rotors (bottom line of parts), battery, two fan motors (top two white parts) and the complete rear end assembly parts (top right). The resin detail is sharp and clean, other than cleaning a little casting flash from the wheel openings these parts are ready go.

The shock assembly consists of two end pieces and a spring. You need to supply your own 1/8" aluminum tube for connecting the ends. The 5/16" X 3.75" spring may be supplied as part of a hardware kit. It has been heated to cherry red and let to air cool. This removes the hardness from the steel to allow one to cut it and stretch/compress it to the size necessary for the 4 shocks. The approximate length for each spring is as follows. The front springs should be 3/4" long and the rear springs should be 1" long. Cut the springs to these lengths and then stretch or compress the springs for the final fit. It is recommended to cut these springs with a Dremel tool and a cutoff wheel. This will result in minimum distortion to the ends of the springs. Cutting them off with snips it is almost sure to bend the springs at the cuts. If more travel for the shock is desired the spring can be expanded as shown. The steel is very stiff so for as much expansion as I have shown on the left, one almost has to pull the spring apart one loop at a time with small needle nose pliers. Spring on the right is as provided.

Below is a picture, provided by Tim, of the frame assembly showing styrene rods to be added by the modeler. Here is an excellent reference drawing Tim has provided for checking the frame part positioning and identifying the dimensions of the styrene rods we need to obtain. This is a picture of the frame kit parts: radiator frame, front outriggers, pedal assembly, cowl bow and rear outriggers. The parts are mostly slip fit as the printer follows the CAD drawing so the outriggers require any primer and/or paint to be removed for fitting. I chose to finish paint the individual parts (pedal assembly will be painted before attaching) before assembly. If too much of the frame is assembled before painting I believe one will find it difficult to paint all the nooks and crannies without over painting or missing some areas. Also the pedal assembly requires other colors than black and I think it needs to be incorporated during assembly as it is inserted between the front outrigger and cowl bow. I am not sure one could pull the bow and outrigger far enough apart for insertion otherwise. Seems like the key part to initially set up is the cowl bow. Some kind of square is essential to insure the cowl bow is vertical to the frame. Once that is established it sets the attitude of the front outrigger and pedal assembly. The height at the front outrigger end point can be checked against Tim's Mechanical drawing. The other front outrigger can then be matched for position. The rear outriggers are to be horizontal and if the mating surfaces are clean they will naturally be horizontal. As everything is a slip fit it is easy to mate all the parts to evaluate the assembly process before actually gluing the individual pieces. Slow (thick) CA glue or epoxy is the best adhesive.

Probably the most complicated part to finish will be the frame. I just used primer coats sanding after each coat but Tim used the Ceramcaot technique and had a much easier time of it. I brush painted the areas with Cearamcoat I could not handily reach with a sanding stick. Cearamcoat is definitely the way to go particularly later with the cowl hoop and the radiator support frame. Note: Do not use toothpicks to hang parts treated with Ceramcoat as they will be glued in by the Ceramcoat and break off when trying to remove the part. Also it is not effective to use Ceramcoat after trying primer because primer seals the pores and the Ceramcoat then just adds a layer of material over all. The Ceramcoat seems to pull into the pores of the RP as it dries and maybe surface tension smoothes it out. Remove almost all the Ceramcoat from the surface with a Q-tip or paintbrush, including the stuff that “puddles†in the grooves and fillet areas. Hang the parts to dry when there is virtually no Ceramcoat on the surface of the part.

Finishing the new TDR material requires a different technique than before. The Aluminized (Grey) parts are very hard and not easily sanded down as the original RP material. The Nylon (white) parts are tough to sand and can leave a peach fuzz finish. Tim has found "It does "peach fuzz" if you sand it with the "grain", meaning with the layer lines. He has had the best luck sanding against "the grain" with emery boards. It seemed to smooth right down. He also used an X-acto knife to "shave" the few heavy grain lines. When he says shave, he means tilt the top of the knife IN the direction of movement. It seems to take the "peach fuzz" off." Tim has suggested a new technique below. It really saves finish time. I tried it and I also tried just using primer then sanding the parts. Tim's suggested method is faster than multiple layers of primer and sanding. One cannot achieve a really smooth surface with one primer coat. I was happy in some cases with three layers of primer and light sanding but in some cases I wound up with more layers of primer and light sanding. I think the difference was probably the thickness of the primer coat in each step. When dealing with the Nylon parts, like Tim, I also found that scraping (like spreading butter) the surface with an X-acto or scalpel smoothed the primed surface best. What we are doing is filling the void pits while just filing or sanding off the peaks to reduce finish time. We only need to remove the layer lines and work the surface, with a file for the Alumide and a sanding stick for the Nylon parts, to remove any loose stuff or any "peach fuzz" The material on the left in the picture is called Ceramcoat and comes in a wide mouth jar as shown or in smaller 4, 6 and 8 oz. bottles. I used the Ceramcoat on half the parts and the primer shown on the right on the other half. Tim's method is much faster but you do have to watch for drips. I fought his technique at first but if you do a few parts at a time and pay attention to drips or build up it works out to be the best procedure. Here is the process Tim found suited him best in his own words: 1) Do a quick light sanding/filing of the parts. (I like using my micro files) Also, look for any loose plastic residue in some of the small holes and crevices and remove it. 2) Pass a small, correctly sized, brass rod through a hole in the part. This is to give you something to hold the part by and to suspend the part during the curing process. I do not recommend using styrene rods, as they are not very stiff and are likely to sag and bend while the parts are drying. Brass is the best choice. 3) Submerge the part into a bath of something called "Delta Ceramcoat" All-Purpose Sealer. I found it in the paint section of my local Michael's craft store. This stuff is used to seal the porous surface of ceramic crafts, so it could be in the ceramic section too. It appears to be an acrylic substance that has a milky white color but dries clear. It comes in an 8 oz bottle. Submerge the part and let it soak up the liquid for about 30 seconds or so. 4) Remove the part from the bath, shake off the excess, then using a Q-tip just dab off any excess that is collecting in the crevices. Check back occasionally for drips or build up in any crevasses. 5) Wait about 45 minutes and then lightly wet sand. 6) Repeat steps 3 and 4 again. 7) Then hang the part and let it dry for 24 hours. 8) Using 220 grit wet/dry sandpaper WET sand the parts to remove any excess Ceramcoat that you find. I have not found the excess Ceramcoat to be a major problem as it shrinks quite a bit as it dries and does not result in any nasty hanging goobers or anything. If you find some spots that have excess buildup, just wet sand it away. NOTE: I do NOT recommend dry sanding this coating material. It seems to ball up and create goobers that need to be removed. 9) Shoot with a standard high build primer. Nothing thick, just a good wet coat of primer, and let it dry. 10) Sand and paint as normal. That is it. No major sanding. Just saturate the part with a sealer, wet sand, and paint. I do not know exactly what this sealer is made from. It appears to be an acrylic. It has no odor and it cleans up in soap and water. So it is really hobby room friendly. I would recommend building some kind of wooden rack that you can stick the brass rods into while the parts dry.

Strengthen the Frame To ensure the frame does not deform over a long period of time, Tim has suggested we insert a ¼" brass tube in the hollow frame rails. A ¼" brass tube from K & S would work great. The tube needs to span the distance from the rear most back suspension mount to the front most front suspension mount. It will be captured by the radiator frame but should be epoxied in place. Tim suggests these steps: 1) Test fit the tube in the chassis (no epoxy).

 2) Determine the length to cut the tube, remove and cut it.

 3) Test fit it back in the frame, (no epoxy)

 4) Test fit the radiator frame to the frame tubes with brass tubes in place.

 5) If all looks good, disassemble and remove brass tubes. 

 6) Mix up some 30 or 60 min epoxy and apply to outside of the brass tube. 

 7) Insert the brass tubing down into the frame tube.

 8) Push it all the way in with a scrap piece of tubing. 

 9) With a tooth pick, wad of paper towel, or similar remove any residual epoxy that is in the mouth of the frame tube.

 10) Stand the frame up so that the ends of the frame tubes remain open and free from epoxy as it sets. The radiator support mounts in these openings and they must remain clear.
 



New Parts - Different Material Another box of parts showed up today and I can see why this kit could well be bought in sub kits. The chassis and suspension consists of enough parts for three or four stand alone kits and we still have the engine, interior, body, wheels, etc., etc. The chassis is a work of art. Thankfully we don't have to put it together. I had problems trying to construct motor mounts for the Hemi 426 blocks when mounting them to the Deuce chassis. Note they are built in here! All the little holes for mounting hardware are in place and clean as a whistle. The material feels as strong as Tim mentions but I am not about to test its overall tensile strength. I am very heavy handed and it is nice to know I will not have any problems with long thin parts. I have not identified all the parts that have arrived so far but they are an initial mix of chassis, steering, motor and interior. Can't wait to start grouping them and begin the finishing process. I have been working on two finishing methods for the original stiff suspension parts and that should be covered next.

These parts feel very solid to me but Tim suggests applying some CA glue to the surface of the parts to add just a little bit more stiffness to the parts for long-term sag prevention. I have tried the process and discovered a few pitfalls. 1. Careful or you might be going to bed with an A arm glued to your finger. 2. The CA glue quickly wicks through the parts farther than one would think. I tried the old idea of toothpicks stuck in styrene to hold and dry the parts. You can do this if you only coat ½ of the part at a time and leave plenty of space between toothpick and where glue touches the part. Still I had a few toothpicks glued in place even doing this. 3. I had to cut off those toothpicks and drill out the residue. The wood is much softer than the RP material so careful use of a #62 drill in a pin vise will generate a pilot hole and then you can drill to the original hole size. I am pretty sure the RP material will push you into whatever wood is left because it is much stiffer than the wood. Just don't get in a hurry and angle the drill. Edit: Suggestions by Tim for a better method of using CA on the parts: 1) With the toothpic method, do half the part and let it dry on the toothpick. Just make sure the part is hanging down so maybe the glue will wick away from the toothpick 2) Better yet (no toothpick) lay the part down on some wax paper. Just make sure no glue is puddeling where it touches the paper and you can also tilt the part, lean it up against something, to minimize the contact patch with the wax paper 3) Use a CA kicker spray. The CA will dry instantly if you use this. You will just have to wash the part in some mild detergent to remove the kicker.

There have been few, if any, times I have felt privileged in my 80 years but this is one of them. Just as I was trying to convince the wife some of our social security should be budgeted for a new TDR model Don asked if I might be interested in building and debugging one of the first prototype 427 roadster kits. As I answered YES 2 microseconds later I could not believe my luck. I have built just about every kit TDR produces except the Allison (no way would the wife stand for that expenditure) and I think this kit will be THE bell ringer. As you will see there is a new process that I hope Tim might discuss as we go along. What a difference with the material. The parts seem to have a much higher resolution finish. Round and slanted surfaces are smooth. Through holes are sharp and clean. The material on these first parts seems much harder (stiffer?) than the other kits. Still need to do sanding on parts that represent steel rod or tubing but I bet there will be no need for sanding cast parts like engine blocks. One really great thing about this new material is that dropping the parts is no longer a catastrophe. I have a habit of dropping parts and I shattered some of the parts on the Deuce IFS/IRS and did so many on the first Offy I had to buy two kits. I have inadvertently dropped a few of these parts already from chest height to a tile floor with no problem. (Don't start tossing parts around at random but you don't have to have a heart attack as a part slips from your hand.) I just received initial parts for the wheel suspension assemblies. These are the front spindle parts including shock end pieces. There is a hole the FULL length of the spindle that is about 0.047" diameter and is a slip fit for a 00-90 bolt. (Can you imagine that!, printing an inside hole that diameter with no obstruction.) Right now I torn between possibly using two ½" long bolts inserted into the spindle from each end to hold the assembly together or possibly buying some 0-90 rod to run the full length of the spindle. We will see as the model progresses. The rod with nuts would capture the A arms best but the hex head cap screws (bolts) may finish better and the ½" length may have enough friction to hold the parts. We will see when we get that far along. These are the rear wheel mount parts including shock end pieces. This is the radiator frame.

Once the aluminum is bent to shape does it require any type of bonding (ie. solder) to maintain shape or position?

The modeling world will never be the same from here on out!!!

Technology advances. This years computer makes last years lame, etc. I got one of the first model sets when it came out and went through the learning experience at the time. Actually I kind of enjoyed the challenge. It was state of the art at the time. Now the art is advancing. It went through offering resin parts after an expert really worked over the original and made resin masters I guess. Now a new technique seems to be emerging with the new complete roadster they are discussing. Some parts will apparently come from a new RP technique. I will buy into the new roadster parts when they become available and probably a year or so from now they will have achieved an even better technique and I will buy into that also. I won't look back each time. I will just feel it is pioneering.

Somebody is an A#1 modeler because I sure could not get DRAKE to stand out like that on the front housing when I did the old style.

How about a list of parts from the existing catalog that will be used on the new 427? like brakes? etc??

Lordy Lordy - still my beating heart. I am in love again. Don't know how I am going to afford it but this is one I have to start getting a peace at a time!!!

Cato - how did you attach the woven tubing. Everything I tried wicked down the tube and stiffened it. I liked woven better than wire but could not work with it.

Professional recovery Cato.

That is one beautiful paint job Cato. I am glad you didn't post before me, I would not be able to follow this build. You really have this car researched to perfection.

Really a great model. I like the weathering. I may have to rethink my finish. Unless you guys can come up with more sea stories I guess this closes the thread. Been fun talking to you.

Waiting - waiting

OH - I CAN ENJOY THAT. Gosh what a beautiful model and the way you have it displayed is perfect. Hey you guys - keep the sea stories coming.

That is amazing as RP printers have resolution restrictions just like digital paper printers. The printers to which you refer must have been in the class of at least a 300dpi printer. I bet TDR would love to know the make and location so they could get a quote.

Keep up the racing dialog - I am enjoying it. The last sports car races I attended were at Riverside CA watching Porsche Speedsters chase Corvettes (which is why I thought the GT40 would be bigger than the 935.) Cato - if you haven't tried to wire up the rear deck be sure to round off the attachment post. I have a way of breaking just about every delicate part and in trying to hook the ring over the post I broke it. Also you have to file down the bulkhead thickness where it goes over the frame attachment pig. That is a very thin peg and the bulkhead is too thick to slip between the frame and peg end. I also broke one of these before I discovered the problem.

Not bad for a 40 year old car with the same wheel base as a porsche.

I did not have a feeling for the actual size of the GT40 until I placed it beside my Porsche 935. I thought it was a boat until then. Be interesting to hear some relative 935 to GT40 specs and discussion. There must be 30 years difference between the technology.