Sennebogen HPC40

Good day class. It is near the end of the year so before your final test, which counts for more than 50% of your grade, I thought we would do a semester review and cover most of the material you will see on the test. For today’s lesson we will start with a subject that I have in the waiting to do pile for a while and am very excited to see it finally make the table. The model is a Sennebogen HPC40, a twin steer 8x4 Mercedes chassis with a great four section telescoping crane complete with fly jib. I really like the forward outrigger set up on this crane, a classic X pattern, giving a wide platform for those long layouts. Especially adapted to tight quarters and city use, I think this will be a great subject for our review.

Here we start with the subject as it is produced by the model manufacturer. Yucky yellow (that is a technical term you may see on the test)

One of the nice things about this crane is its simple modularity, the crane body, out riggers and all associated hardware are a complete separate module from the rolling chassis.

As always we disassemble the model al the way down, taking everything apart as far as it will go and we organize out parts bins one for the chassis components and one for the crane components. These bins may look like disposable tupperware but are in fact very complex and specified by me for correct parts storage. Things that go in are tires, screws, glass, boom spring clips and all the other parts that do not get painted.

Sand blast and strip to bear metal

And then prime the parts for paint.

Apply the red paint to the parts that will need it. There are two categories, one where the red will be the finish coat and ones where red will be the under coat stripe. It is important to build up your layers of paint thin, especially on the boom sections to ensure free and easy travel after assemble. All pieces that get red should receive the exact same number of coats to assure uniformity of color.

Now this where the entire class had trouble-masking under stripes. First make sure the subject parts have had a least 24 hours to dry before attempting masking. Failure to do so could result in the paint leaving with your tape at removal. Second, get tape specifically designed for paint masking. Third if you have a stripe that is going to be on separate pieces, put them together, then mask, using an xacto knife to separate after you have rubbed the tape down. Otherwise you have mismatched stripes-yucky. The final trick to a successful mask is to apply a spray clear coat over the masked model to seal the edges and avoid seepage.

Now apply the black top coat to all of the remaining pieces, including your masked ones. Allow the paint to dry and harden and then it is time for the revel

Boom tips get the same mask tape, but do not spray the clear coat on them, instead use a tooth pick to rub the tape on firm and then wrap the entire section in clear plastic wrap to protect from over spray.

And finally all of our masked pieces-perfect and critical portion of the grade on the test

And today’s model has a red bumper and white safety stripping so lets go ahead and paint and mask that too.

All pieces painted and time to organize out parts for the re-assembly

Lets start by getting our rolling chassis back together

And now for the crane section. As this is fairly simple, lets take a moment to focus on the boom re-assembly and those pesky little spring loaded keepers. Care must be taken when pushing these guys down to clear and get inside the next section otherwise they will launch and you will spend the next several hours on the floor looking for the two pieces-those springs have a lot of energy and can fling the part in the most unexpected directions.

Once again we are back to our two sub assemblies and with a quick turn of the screwdriver its back together

Then it is off to the decal shop for the proper application of decals and the model is ready for viewing

That’s the bell….Your test is tomorrow, so study hard! Class dismissed!

(okay I have completely lost my mind, but I am happy once again-thanks for putting up with me)

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