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  #1  
Old 08-31-2020, 11:40 PM
Tgrzes Tgrzes is offline
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Default Ferrara Tanker

Hi everyone. I’m new to the forum and new to building in 1/14 scale. After seeing all the great builds in this forum, I decided to give it a try. For my first attempt, I’m looking to build a 2500 gallon Seagrave tanker/tender from a Globeliner. My department is currently spec’ing out a new Seagrave to replace our 2003 Seagrave, so it will be interesting to see which is finished first. My plans include a working deck gun, .9 gallon tank, drafting capability and dump valve with portable pool. So far, I have a rolling chassis with new frame rails, extending the wheelbase 4 inches and adding 2 inches to the front end. I’ll try to start posting pictures soon as soon as I figure out how.
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  #2  
Old 09-01-2020, 08:55 PM
jerry56 jerry56 is offline
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Default Re: Seagrave Tanker

this sounds like an interesting project.... What are you using for the rolling chassis.
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  #3  
Old 09-01-2020, 10:29 PM
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Default Re: Seagrave Tanker

I love to see more fire trucks here. Looking forward to seeing progress pictures. Also, today I learned that US fire crews use portable pools to distribute water.
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  #4  
Old 09-02-2020, 09:41 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

I'm starting the build based upon our existing 2003 tanker below, then I'll starting incorporating things from the new tanker over the next year as the manufacturer starts providing drawings and pictures.


So far, it's mostly a stock Globeliner chassis except for the longer frame rails.


I decided to keep the motor/transmission forward, so I made a longer drive shaft.


I plan to carry just under a gallon of water, which is about 8 lbs, so I need to stiffen up the rear suspension. Any suggestions on how to do that would be greatly appreciated - stiffer leaf springs, add a leaf, heavier springs in the shocks, etc.

Last edited by Tgrzes; 09-11-2020 at 10:10 AM. Reason: Replace deleted picture
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Old 09-02-2020, 06:05 PM
jerry56 jerry56 is offline
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Default Re: Seagrave Tanker

Wombii is the fire truck guru.... he might know how to stiffen the suspension ...I know you can get the springs and helper springs on Amazon....
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  #6  
Old 09-03-2020, 07:08 AM
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Default Re: Seagrave Tanker

I didn't stiffen my suspension as the Tamiya suspension was already stiff enough for me, and the airport trucks are a bit lifted for light offroading. I also ended up with only about half a gallon of water, with the weight centered in front of the rear axles, so the stock setup works ok. If there is room to add a leaf or two, that is probably the easiest route.

What I can tell you though, is don't underestimate the need for chassis crossmembers. I'm using a couple more than the Tamiya instructions suggests, and I still have way too much rotational flex with the added weight. Even if it seemed very stiff while building. Keep in mind my body parts are body + 3 separate modules, so the body adds no stability in my build. Your mileage may vary.

With a truck that heavy and with that much custom bodywork with long overhangs both in the front and rear, you may also want to start thinking about how you're going to lift it. You probably don't want to grab it by the bodywork. I bolted a handle directly to the chassis frames above the center of gravity.


I'm sure the dump truck and heavy machinery gurus have better input on the rear suspension.

Would love to see more info on how you built the drive shaft. I did a very simple extension with copper brake line and brass tube and it's still held together with masking tape.
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  #7  
Old 09-03-2020, 10:52 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

Thanks for the great input! The flex is definitely something I was thinking about. At the very least, I will isolate the cab, mid pump panel section and rear tank section into 3 separate units just like on the full size truck. We recently parked the tanker on uneven pavement and I was amazed at how much flex there was looking down the side of the truck.

I saw your carry handle in your thread - great idea! I will definitely include one.

For the drive shaft, I cut the stock Tamiya dog bone in half. It's soft enough to easily cut with a hack saw and drill. The new shaft is 3/8" dia. solid aluminum with a 15/64" hole drilled on each end. One half of the dog bone fit perfectly; no slop, but loose enough to adjust in/out easily. The other half was too tight, so I chucked the 15/64 bit backwards in my drill, put some rubbing compound on the smooth end of the drill and ran it back and forth in the hole until I got the fit I was looking for.

With the dog bones adjusted to the right length, I cross-drilled with a 5/64" bit and drove in a split pin. Using a pre-drilled 3/8 bushing in the vise helped keep the bit centered.



I thought about putting a flat spot on the dog bone and using a set screw, but this just seemed easier. We'll see how it holds up.
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  #8  
Old 09-03-2020, 02:31 PM
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Default Re: Seagrave Tanker

This looks like it'll be a very cool build to watch!

It's very easy to add extra helper-springs to the packs, with a little plier or file work you can wrap a second main-leaf around the original main leaf spring. I believe there is some difference between 'semi' and 'hi-lift' leaf springs, but that should let you have more options on getting it to behave just right.

If it's still not enough capacity with spring, there were a couple guys milling 'Walking Beams' that look like a spring pack for the Heavy Haul trucks.

Another idea for safe carry, if i ever start my ALF project i've been thinking about making the step bumpers, rub rail, and all that into basically giant 'rock sliders'. So it becomes all structural frames around the bottom of the body bolted to the real frame
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  #9  
Old 09-03-2020, 07:33 PM
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Default Re: Seagrave Tanker

Thanks for the tip on the leaf springs. I’ll check that out. It’s funny you should mention rub rails tied into the frame. Seagrave has an option to tie the rear rub rails into the frame to protect the rear cabinets. I believe FDNY has been doing it on their rigs and we just included it in our spec.
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  #10  
Old 09-14-2020, 10:38 PM
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Default Re: Seagrave Tanker

I don't know if it's relevant to you, or if you've already considered it, but I stumbled upon some older notes. I originally wanted to use a gear pump that could run both ways, and considered using one way check valves. The most basic would be to have side A be monitor and draft with opposite one ways and side B to tank. Running the pump one direction would spray water from the tank and the other direction would fill the tank. There are one way check valves on ebay down to 1mm now. Might save you some solenoids if it works.
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  #11  
Old 09-15-2020, 10:08 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

I never considered that, but I'll definitely need to keep it in mind for the future!
My mind went straight to valves when I started planning, plus I didn’t know that they even made pumps that worked in both directions. Thinking about it quickly, it certainly seems like it would work for tank-to-monitor and draft-to-tank, but I don’t think it would work for the third option I want, which is draft-to-monitor. Plus at this point, I already have the pump and 2 of the 3 solenoid valves I need, so it will only cost $8 for the third valve.

Here's what I'm planning:


I’ve only bench tested a few parts of the system, not the entire configuration yet. Based on the testing, it seems my biggest challenge will be getting a realistic flow of water out of the ½” square dump chute. Going thru the pump only provides a small stream, so I either need to try a ½” solenoid valve or try building my own servo actuated dump valve.
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  #12  
Old 09-15-2020, 06:28 PM
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Default Re: Seagrave Tanker

Looks like a good plan. Looking forward to seeing how you'll fit it in the truck. From my tests I'd say there will be a surprisingly good flow from gravity alone for the dump chute, especially if the tank is tall.
I hope you'll have good tight plugs for the unused suction ports, as the pump will prefer to suck even a tiny bit of air instead of the tank water.
If you're only using gravity, you might be able to make a simple valve by bending a thin walled silicone tube with a servo. I accidentally bought a lot of silicone tubing that kinked badly when bending. It's used for fish tackle, apparently. If the dump chute is articulated or telescoping, you could maybe solve both with a single servo.

I don't know what type of pump you'll be using.
The real truck probably uses a centrifugal pump. Scale sized ones are commonly found as aquarium or garden fountain pumps. Single direction, very high volume but lower pressure at scale size. Needs to be below water level unless primed. (If you can fit a small one for the dump chute, it might do the job, but I don't know if it will leak air or water through when off).
I went with a diaphragm pump used in cheap high pressure washers or camper / boat kitchen sinks. Single direction, Large size, high pressure, good suction height, pulses the water flow a bit. Also very sensitive to a stray dog hair blocking the internal check valves, from experience.
Gear pumps are bidirectional and very high pressure, lower flow and good suction height. Sensitive to objects like dirt and sand. Scale sized ones are commonly found as r/c hydraulic pumps and r/c fuel fillers. I originally bought a nitro fuel filler pump, but wasn't completely happy with the flow rate. Two of them in parallel would have worked great though. Even though my gear pump had much lower flowrate when unrestricted, it could match the diaphragm pump when the nozzle was very restricted due to the extra pressure.
I think all types might be used as windscreen washer pumps?
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  #13  
Old 09-17-2020, 10:51 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

I have some ideas for the fittings. I have several of these brass faucet valves in the scrap bin that have 3/8” compression fittings. Most barbed fittings for tubing have a tapered pipe thread. The compression fittings have a regular 9/16-24 thread which should make it easier for me to modify the length for a more scaled look and fit rubber washers for a good seal. For the steamer blind caps, I’ll try soldering a plug to close the hole in the nut, then turn it round on the lathe and add some lugs. For the female hose fittings, I’ll solder a barb fitting. I also ordered a 9/16-24 die so I can either make the male ends from bar stock or cut the male thread off the valve body and solder a barb fitting to it. At least that’s the plan for now.


The last couple of weeks I spent a lot of time playing around with battery placement, motor/trans location, tilt cab hinge and new floor design all while keeping the cab interior somewhat to scale. I think I finally have a plan to move forward, so hopefully I can start posting some pics soon.
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  #14  
Old 09-30-2020, 09:31 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

Finally making a little bit of progress. The cab will be lowered, shifted forward and lengthened almost 3”, so I needed a new floor. After a lot of trial and error, I ended up using 1/8” ABS.






I’ll need four more seats, so I may try casting them using fast cast resin.


A coat of white paint for the pink shocks.


Finished up the hinges for the tilt cab.


I’ll eventually attach the cab to the floor with a few screws, so the entire assembly will tilt.
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  #15  
Old 10-03-2020, 10:42 PM
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Default Re: Seagrave Tanker

Very nice floor and hinge mechanism! Before you clone the seats, make sure they're the right size for your cab. I think Tamiya uses the same seat in many of the trucks, so the scale might be slightly off. (I think they're a bit small for the Scania).
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  #16  
Old 10-06-2020, 10:24 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

Thanks for the heads up on the seats! The height is good but the width is 6 to 13mm too small. The driver seat would probably be ok, but the other 5 SCBA seats would be a problem. Hopefully I can scratch build one and cast the rest.
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  #17  
Old 10-09-2020, 10:35 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

The cab is starting to take shape.






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  #18  
Old 10-12-2020, 09:55 PM
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Default Re: Seagrave Tanker

Very nice! You work fast
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  #19  
Old 10-20-2020, 10:31 AM
Tgrzes Tgrzes is offline
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Default Re: Seagrave Tanker

Added some 3/8" styrene angle to the cab so that I could attach it to the floor with screws.






Mocking up the rear body with 1/8" hardboard and hot glue just so I can figure out where to put things before I start cutting plastic.




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  #20  
Old 10-20-2020, 05:07 PM
jerry56 jerry56 is offline
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Default Re: Seagrave Tanker

Nice work, this is moving right along....
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