For the next step, I'm going to drill axle holes with help from a guy at work that has a jig designed just for that purpose. I think we also need to drill out some holes to add metal weights, then paint it. Draeden wants to spray paint it black, then add some decals on top. I think it might look good to then add a coat of clear paint on top of the decals, but I'm worried that we are running out of time to get many coats of pain on, as the spray paint says to let it dry for 48 hours before adding other coats, and we only have about 54 hours until the race on Wednesday evening. Anyone have any good suggestions for fast painting that work well? Unfortunately, I now see we waited too long to get started if we wanted to have plenty of time to do a lot of paint coats. I'll add some more photos as we progress.
Here is a picture after drilling the axle holes, drilling weight holes, adding weights, and filling holes with putty:
Kristi's brother Michael helped me with this part. We also routed out an additional hole on the bottom of the car for the purpose of adding extra weights with hot glue at the race (we tried to leave the overall weight slightly low ahead of time to account for differences in scales.) :
Next, of course, we needed to sand down the putty, which of course took off all the sanding sealer on the sides:
Lesson learned: finish all drilling and putty work before starting any painting steps. That probably would have been obvious with more thought. Next, Draeden is going to paint it and put on some decals, so I'm sure you'll be excited for the next photos.
Here is Draeden's finished car (the decals didn't work very well on the paint we used, so we didn't put any on):
And here is a picture of the car we build for Liam, made out of the other side of Draeden's block (the side that had the axle slots). For some reason some of the small decals did work on his car:
It was a lot of work to get them ready - next year we will get started a little sooner.
water based paints tend to have shorter times between coats. For some clear coats I have done I only needed to wait an hour between applications.
ReplyDeleteThanks Eric for the suggestion. With the time we have left, we will just use water based paints applied with a brush.
ReplyDeleteIt looks cool! Nice work. Eric and I are getting ready to work on his - our pack meeting is in two more weeks.
ReplyDeleteI added a photo of Draeden's finished car, as well as a picture of the car we built for Liam.
ReplyDeleteThe race was tonight and it was a lot of fun. Draeden's car was very fast - he got 4th place overall and 3rd place in the Wolf Den, which he was happy about. They just ran enough heats for every boy's car to race 6 times, twice in each of three lanes, then added the 5 fastest times for each car to determine final placing. Draeden liked it that he was first place in five of his six heats, coming in 2nd place the one time that he raced against one of the three cars that were a little faster than his.
After the official race and pack meeting were over, Liam got to race his car several times, which he also enjoyed.
There's a guy in our ward who's sons win both 1st and 3rd place overall, so I'm going to need to ask him for some speed tips for next year. So far, my main ideas would be to do even more axle polishing with more graduated grades of sand paper, and also to buy a few extra sets of wheels and axles and prepare all of them, then pick out the ones that seem to spin the best. I've also heard that in some cases it can help to setup one of the two front wheels so it doesn't ride on the track, which sounds like and interesting idea.
Nice job Draeden and Liam and Mark! Thanks for sending the pictures. We should have a family Pinewood Derby race sometime. I've never built a car and I've always wanted to.
ReplyDeleteCongratulations on doing so well. In Trevor's first pack they had a rule that all 4 wheels had to touch, and they checked each car at weigh-in. This past year, at the church pack we did not have that rule. This pack is a bit less competitive.
ReplyDeleteOur pack did not check anything other than weight. It seems we could have extended the back wheels behind the car, filed grooves in the axles (so less of the axle touches the wheels) , and shaped the wheels (so less of the wheel touches the track) if we had wanted to. I didn't do any of those because it is my understanding that they are against the official rules.
ReplyDeleteRaising a wheel (which we did not do), and extending the wheel base up to the full allowed car length (which we came close to doing) are not against the official rules, though I have heard that it is not uncommon for some packs to add additional rules governing these areas.
ReplyDeleteIt does seem advantageous to get your rear wheels back as far as possible because it allows more balance while still having the weight as far back as possible. From pure physics/geometric calculations, it seems you want as much mass as possible as far back and as low as possible, because it is the lower back corner of the car that will drop the furthest vertically from the starting point to the point when the track is completely flat.
Eric is very excited to work on his car. Looks like you guys did a great job!
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