Straightening a warped body

[emptyd]

My kids and I are planning a routed out wing or wedge this year to allow greater flexibility in weight placement.

We did a test body with a cheap club block while waiting for the good ones to come in from MaxV. We found that the body warped after having so much material removed. The warp in effect lifted one wheel.

We really like to use the predrilled axles holes and don’t expect MaxV’s wood to warp – but if it does can we fix it so that we can continue to use the predrilled holes?

I’m thinking about water soaking the body once it is routed out, placing it on a truly flat surface under heavy weight (or clamps) the slowly drying it with a little heat from a light bulb under a tent.

Any other thoughts?

[Stan Pope]

Wow! Nasty problem!

I and the boys that I assist regularly cut BSA kit blocks to 1/4" slabs and then remove most of what is left. I've noticed no tendency to warp. MaxV's blocks ought to be at least that good!

To resolve warp ... consider steaming the body instead of just soaking it. I think you should get better penetration. (That is what I've seen the feller on The Woodright show do!)

Your "pressing" plan should work.

[DERBY DOPE]

Personally i would send away and get this "hugh pack" For the small price you pay you can do alot of testing pick out the best axles and wheels and test all the blocks,

http://www.hobbylinc.com/htm/ppr/ppr10051.htm

[Hurly64]

All wood has a natural tendency to warp, to some degree. It is a function of species, grain pattern, knots, humidity, you name it. Pine is one of the more stable woods, and at such a small size, warpage shouldn't be very noticable. If you are concerned and can pick your blocks, try to get a a block with a tight, straight grain pattern. Thin-cut blocks will fare better if the ring patterns on the end of the block are at least at a 45 to 90 degree angle(perpendicular) to the face of the block. (This is called rift sawn or quartersawn). If the ring pattern is less than 45, or parrelel with the face, this will be a less stable piece of wood.
The down side to tight grained wood is that it will be heavier. So, there is a tradeoff between stability and weight with these little thin-cut blocks.
Keeping them thicker will help minimize the warpage, too.

[Pinewood Daddy]

I bought a dozen kits a couple of years ago and we use the blocks that have nice straight grain and weigh about 100g. Many times you can get 2 cars out of one block. Stan will say you can get more!!

[Stan Pope]

Stan will say you can get more!!

There's enough wood in that car to build two more cars ... and a sailboat!

[Stephen's Dad]

We've never noted much warpage but we have found that taking out too much "meat" resulted in some nasty breaks especially at axle pods. To solve this problem we now choose a light block with loose grain (weak) & slice it into thin strips on the table saw. Stephen then glues the strips back together with the grain running opposite each other. Once the clamped block is dry he proceeds as usual to shape it into his car. The now laminated block seems much stronger & even with his preferred designs (pretty radical) we haven't seen one break.

I would think that this procedure would also help resist warping.

[Pinewood Daddy]

We've never noted much warpage but we have found that taking out too much "meat" resulted in some nasty breaks especially at axle pods. To solve this problem we now choose a light block with loose grain (weak) & slice it into thin strips on the table saw. Stephen then glues the strips back together with the grain running opposite each other. Once the clamped block is dry he proceeds as usual to shape it into his car. The now laminated block seems much stronger & even with his preferred designs (pretty radical) we haven't seen one break.

I would think that this procedure would also help resist warping.

That works fine if you don't have to use the slots. Last year we drilled the holes first and then slotted with a saw I got from a guy at work. (not easy) Or you insert with a piece of harder wood, such as maple.

I've always wanted to build a car from laminated strips of different woods.

'Tis the season!! Welcome back Steve!!

[Stephen's Dad]

Dave,

You guys can still use the original axle slots. Just make sure the bottom slice is a little thicker & stays on the bottom during the glue-up.

Merry Christmas!

Steve & Stephen

[cubdad]

Hi,

Straightening successfully seems that it would need more work and time than can sometimes be fit in before a race. It also seems like it would take longer than just starting over with a fresh block.

I like the cars thin too. Consider this: coat the bottom of the block with MinWax woodharderner, when that dries fill in the axle slots with epoxy. When that all dries, drill axles holes in the slots through the hardened epoxy. Then cut the block for the car shape you intend. Then coat the newly exposed top with MinWax woodharderner. An additional bonus of the MinWax product is that the wood sands smoother and quicker. Anyway, in the end this should let you end up with a very thin straight car.

Good luck.

[cubdad]

forgot to mention the following: MinWax uses some nasty solvents to carry epoxy resin into the wood fibers, so it needs to used by an adult with ventilation and allowed to dry in a ventilated area away from people and pets, you can also use a cheap brush to aplly it and just throw it away after