These unique wheels are available with two types of tire tread, smooth ribbed, as illustrated and the diamond tread as seen on some World War Two aircraft, most noticeably the Curtiss P-40 or the North American AT-6.
The high strength Lexan wheel hubs snugly clamp the tire to retain pressure. Disassembly is not normally required unless there is a need to increase inflation pressure. (See Tire Inserts)
Assembly
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1.
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Place inboard collar on the axle or solder a washer on the axle as desired. This collar or washer will prevent the wheel from trying to ride up the curve on the wire and causing drag on the wheel. |
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2.
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Check that there are no burrs or roughness on the wire. It is better to file a slight radius or bevel on the end of the axle. In addition, the axle should be free of blemishes (such as vise jaw marks) and if any are found they should be carefully removed with a fine file and the wire polished with #600 emery paper. |
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3.
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Slide the wheel on the axle until it stops against the inboard collar. Slide the outboard collar into place against the wheel and lightly tighten the setscrew. |
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4.
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Check that the wheel spins freely and if it does not, then move the collar outwards until a barely perceptible in-out movement of the wheel on the axle is detected. The wheel should now spin. |
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5.
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Use a fine felt tip pen to mark the excess wire against the collar then remove the collar and wheel from the axle. |
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6.
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Grind off the excess axle wire then carefully remove the burrs. |
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7.
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Replace the wheel on the axle and again check for free spinning before finally and firmly tightening the setscrew on the collar.
NOTE: Be sure to use blue thread locker on the setscrew.
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Hub Cap Options
Spoke and smooth hubcaps are supplied with your Robart Scale Wheels and either hubcap may be fitted on the outboard side. However the spoke hubcap is slightly “dished” and might interfere with the wheel collar on the smaller sizes of wheel, and therefore the thickness of the collar must be reduced by grinding or filing. Alternatively, the wheel can be retained by soldering a washer to the axle.
NOTE: Before soldering the washer in place, put a paper washer as a shim between the wheel hub and the washer. This will provide proper clearance and also insulate the plastic wheel hub from the heat of soldering. In any case, soldering should be done as speedily as possible to prevent damage to the hub. The paper washer can be torn out with tweezers on completion.
Hubcap may also be fitted on the inboard face of the wheel, in particular the smooth hubcap, which nicely simulates the brake drum. To achieve this, the wheel should be off the axle and the hubcap snapped into the inboard face of the wheel.
Use the axle hole as a drill guide to drill through the hubcap. Open out the hole to clear the inboard washer or collar.
Hubcap are a snap fit in place, but a hard landing has been known to displace them. To avoid loss apply a few spots of glue to the flange. Suitable glues are Pacer Plastic-Zap CA++, Testor’s Plastic Cement, or RTV pipe cement as used by plumbers to join PVC pipes (available from the hardware store).
Molded nylon reducing bushings are provided with each pair of Robart Scale Wheels. These bushings can be inserted into the wheel hub axle hole and will match the hub to fit 1/8”, 5/32”, and 3/16” diameter axles.
Tire Inserts
Also available from Robart are special, firm, foam inserts which can be stuffed inside the tire before reassembling the hubs. See your dealer or call Robart direct.
# FOAM1
Foam Inserts for 2" to 2 1/2" wheels
# FOAM2
Foam Inserts for 2 3/4" wheels
# FOAM3
Foam Inserts for 3" to 3 1/2" wheels
# FOAM4
Foam Inserts for 3 3/4" to 4" wheels
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