OK guys another question for you. I am used to using the pro body jig to drill my axle holes. I recently purchased the silver bullet from john. I am a pretty simple man. Can I use the pro body jig where I want my holes, use a pin vise to put a smallmark in the wood and then just slide it in the silver bullet and drill? I am just trying to make it more simple and not have to measure much. I typically extend the wheel base . Would this be an acceptable way to do this or is there a better way. Thanks guys
pro body jig and the silver bullet
- Thread starter whitaker717
- Start date
not off hand, it was a guy in another league, stumbled upon it. I'll think about it see if I can remember.
I think it was Spacewalker who had a video where he mentioned using the Pro Body Jig to mark where to drill and the Silver Bullet to hold the block to drill in a drill press.
I know a person DT also said to used the PBJ for starter "wholes"..... I would say NO don't do it! Drilling a canted hole into a straight starter hole is just asking for trouble. The bit will try to follow the straight hole and your drilling will be off. Even if you use a canted DW fixture for starter hole it will not be at the same angle as you are drilling with the Silver Bullet.... no machinist would ever do that and neither should you.
I agree with Scott that actually starting a whole would be a bad idea. SW just used it to mark. For a first timer, it might help -that was one of my problems, but after I found a SHARP pencil and a VERY GOOD ruler, and practice, wouldn't see it needed. certainly wouldn't buy one.
I use the pro body tool to locate the holes. If you do this, one issue to look out for is that it locates the holes too high up on a thin (1/4 inch) design. So I've created a couple custom "shims" to place between the bottom of the block and the tool when I clamp the block in the tool. The shim raises the block in the tool, and thus lowers the hole location. I use one shim to locate the rear and DFW axle holes. Then I use another, thinner shim to locate the hole for the lifted front wheel.
I used to drill a shallow starter hole with the PBT and pin vise, but don't anymore. Now I just make a couple light turns with the pin vise to clearly mark the location. I doubt a shallow starter hole would hurt, but it doesn't help at all either - so I don't really see the point.
I used to drill a shallow starter hole with the PBT and pin vise, but don't anymore. Now I just make a couple light turns with the pin vise to clearly mark the location. I doubt a shallow starter hole would hurt, but it doesn't help at all either - so I don't really see the point.
I think that video shows that so there is a reason to have a PB Jig.... I guess I don't know why you would buy a $40 jig to mark holes like that? I just mark lines with an old sliding tee square and then drill. The height is already set, is perfect, and you can't change it. The only thing that does is make the rear wheels across from one another.... can't you do that with a pencil line? and to be honest it doesn't really matter if they are a little off, they are still not toed in or toed out, they still are aligned and the car will run fast. I like SW, but I just think that is a way to sell PB Jig's...
What everybody really should be doing is using a drill center prior to drilling with a #43 or #44..... a drill center is used to get the drill started in the right direction. You are reducing your odds of having a good drilled block by doing it with a PBJ.... I am guessing people that do it that way have a high scrap rate....
What everybody really should be doing is using a drill center prior to drilling with a #43 or #44..... a drill center is used to get the drill started in the right direction. You are reducing your odds of having a good drilled block by doing it with a PBJ.... I am guessing people that do it that way have a high scrap rate....
A tip I learned from super machinist BSB...
A center drill is a stiff "bit" that is used to create a starting point for a regular drill bit. You know how when you try to drill at an angle the drill bit wanders and doesn't usually start where you want it to start? A center drill is used so this doesn't happen.... everybody is drilling at an angle for their rears and to some extent your drill bit slips and a center drill stops this...
Here are center drills and they come in every size...
They key with the Silver Bullet is you have to have your fence nailed down and then you have to keep your Silver Bullet from shifting when changing from the center drill to the drill bit. You are drilling with both of these during the same set-up... exact same position. John shows using a magnetic base type thing to keep the block in one spot, I use a 1-2-3 block and a clamp... a clamp and a scrap of wood would work...
A center drill is a stiff "bit" that is used to create a starting point for a regular drill bit. You know how when you try to drill at an angle the drill bit wanders and doesn't usually start where you want it to start? A center drill is used so this doesn't happen.... everybody is drilling at an angle for their rears and to some extent your drill bit slips and a center drill stops this...
Here are center drills and they come in every size...
They key with the Silver Bullet is you have to have your fence nailed down and then you have to keep your Silver Bullet from shifting when changing from the center drill to the drill bit. You are drilling with both of these during the same set-up... exact same position. John shows using a magnetic base type thing to keep the block in one spot, I use a 1-2-3 block and a clamp... a clamp and a scrap of wood would work...
IAE Racing said:
Yes, but you can't drill a pilot hole with a standard drill bit and definitely not at a different angle than the hole you are drilling in the end..... well not if you want a good aligned body.
The easiest way is how scott described. Build a fence that can be locked down. It was very simple and while it does take a little more time it's worth while. Mine is very simple. I took a 3/4"x 5" piece of MDF board and drilled 2 holes where my drill press platform fits. Dropped in 2, 3/8" bolts with washers and wing nuts so it can be secured in place. I then cut 2 pieces of wood that "the block" will rest against. These pieces of wood are different sizes, based on the heigth of where I want my axle holes. From there it's easy. My rears are 5/8" measured from the rear and I draw a line on both sides of my block (car body). Front wheels are 4 1/2" (our pack rules) from that line and draw another line. I then line up "the block" up against my rail with my specific rear wheel piece of wood inbetween the block and rail. Both rear wheels are then drilled at the same heigth and same distance (drill middle of the line). If this explaination isn't clear or you need pictures send me a message with your email and I'll show you what I'm talking about with pictures.
5KidsRacing said:
In my case, I already had the Pro Body tool. So no extra money spent. I also wouldn't recommend buying the tool either just for locating the holes - that *would* be silly and overkill - but sense I already have one laying around thought I might as well use it for something.
That has not been my experience.
I wasn't trying to direct my comment directly at you lightninboy... I bought that stuff too... I am just trying to help other people not to make the same mistakes I made..
- Nov 24, 2011
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I think what's scott is referring to, by using the PBJ and marking with a pin vise and #43 or #44 drill bit, you're starting your axle hole straight vs cant'd which can screw up your car body (high scrap rate). I agree, I dont see a problem using the PBJ to mark you points where you're going to drill your axle holes. I just wouldnt mark them with a pin vise.
5KidsRacing said:
Scott has been a HUGE help to me and I'm sure to many others. Quick on responses and always had steer'd me in the right direction (nice pun huh?) He, along with many others, have been gracious to give us n00bs the secrets, tips and tricks to make a super fast pinewood derby car. I dont know too many people out there that are willing to give up winning advise so easily as they do. I'm just waiting to take private lessons from scott first hand /images/boards/smilies/smile.gif
