A 3D printed Drill Guide...worthy idea or not?

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Vitamin K
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A 3D printed Drill Guide...worthy idea or not?

Post by Vitamin K »

So one thing that has always been sort of near to my heart in regard to Pinewood Derby stuff is not wanting to see the people that have lots of money to spend have a huge advantage over those who mainly put in time, effort and brains. Hence why I a hate the idea of people buying premade cars to race, or using lathe-lightened wheels in scouting races.

When my kids and I build cars, one thing that we do use is a precision drill jig template that somebody was actually kind enough to gift to me. It really makes it very easy to get perfectly aligned rear wheels at a 3 degree angle without the fuss of aligning bent rears.

(Just to be clear...aligning bent rears IS workable, and I've had tremendous success with Stan Pope's counterweight system to do it. It's definitely doable and accessible, but it's really hard for me to "sell" to dads at a typical workshop. Especially when I can hand them my drill jig to use and they can get the car set up for rail riding in about 5 minutes.)

My main issue with drill jigs is...they're expensive. They cheapest I see on the market is like...85 bucks right now. That's not a bad investment, honestly, but it's kind of daunting for somebody just starting out with a kid in Pinewood Derby.

So, my thinking is that since 3D printing is a thing and very accessible, it would be helpful to develop a 3D-printable drill jig that just requires that people purchase a standard size of hardened drill bushing to insert into the jig and then go. Bushings are somewhere in the neighborhood of $15 each from what I can tell, so for a jig that will let you drill your rear axles, you're looking at $30 bucks plus printing costs. Maybe $60 if you want to drill straight fronts too?

Does this seem like a useful project to offer? I'm sort of torn on whether or not it would really be beneficial or not.
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Re: A 3D printed Drill Guide...worthy idea or not?

Post by FatSebastian »

Vitamin K wrote: Tue Feb 28, 2023 1:26 pmDoes this seem like a useful project to offer? I'm sort of torn on whether or not it would really be beneficial or not.
Hi K! Can you elaborate more as to what you mean by "to offer"? Would you be offering the 3D printed jig itself (sans bushings) already printed out, or just the files(s) that someone with a 3D printer can use to printout their own jig?

I have seen a 3-D printed jig with no bushings for about $16 + shipping. I have also seen at least one $85 jig with four bushings, and I suppose that it is also 3D printed.

If your estimate of 4 bushings = $60, and the commercial example of a 3D-printed jig sans bushings = $16, then I agree that $85 for an out of the box solution doesn't seem like a bad investment...
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Re: A 3D printed Drill Guide...worthy idea or not?

Post by Eagle »

VK there are so many things you could do, but spending your time to recreate what has already been done well doesn't seem like a good use for it. If someone wants the best repeatable drills then they have to look at one of the money options. Best thing, just like the track, is for the troop to make the investment.
As to the 3D printed I have done non bushing ones for some specialty builds. They are ok for a few drills.
If you add up the costs, not to mention design time and what else the http://www.TurboDerby.com jig has to offer for $85. you would be hard pressed to beat the price.
If someone wants decent drills for a lower price they should look at Pro Axle Hole Driller Tool from http://www.Pinewoodpro.com for $19.95. It comes with the bit and can be adjusted for different widths and will likely fit up in fender wells.

The Clear Jig is still my favorite.
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Re: A 3D printed Drill Guide...worthy idea or not?

Post by whodathunkit »

VK welcome back!

I won't fib here I have a lot of various axle drilling jigs. from DW.. to cant say vender's and so on that have been talked about on this topic.
I have tried a lot of them and collected different types of jigs threw the years.. however I have not tried the non bushing 3d print jigs.
And the one thing I see the most that flat out damages the jig's .. is if your using the wrong drill bit size for the jig.

Word of caution about the many different type axle jigs.. Is to check the drill bit size or drill bushing size that the jig uses.
so you don't damage your jig and or investment by using the wrong drill bit size in the jig.

The Pinewood pro jig uses a 2.2 mm drill bit.
Some of the different jig types with drill bushings on the market use a #43 drill bit.
Derby Worx jigs #44 drill bit

#44 diam (in) 0.0860 diam (mm) 2.1844
2.2mm diam (in) 0.0866 diam (mm) 2.2000
#43 diam (in) 0.0890 diam (mm) 2.2606
Last edited by whodathunkit on Wed Mar 01, 2023 9:11 pm, edited 1 time in total.
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Re: A 3D printed Drill Guide...worthy idea or not?

Post by Eagle »

whodathunkit that is great info. I didn't know about the size on the PinewoodPro. They sponsored http://www.TheWestCoastGrandPrix.com this year. A couple of the jigs were included. I was happy to not have to keep transporting my jig(s) back and forth. It seemed like when I needed one it was already in the wrong place. I noticed that it was harder to put the axles in, but did not equate it to smaller drill bit.
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Re: A 3D printed Drill Guide...worthy idea or not?

Post by FatSebastian »

Back to the OP's original question...

I completely sympathize with Kurt's perspective and understand his motivations for offering an inexpensive tool. A jig, when coupled with an inexpensive pin vise, is the probably one of the most fool-proof speed-enhancing tools available, and a real time-saver. I will offer some encouragement and say there might be a need for yet another 3D printed drill guide, if inexpensive enough, for some of the following reasons...

1. Jigs without bushings simply don't last; they are easily damaged and probably get used beyond their useful lifetime due to wear. It would be nice to have an inexpensive (relatively speaking) 3D-printed jig with inserts that the user can have confidence that it retains accuracy and that he isn't significantly damaging it every time it is used.

2. Expensive jigs with guide inserts don't seem to be user serviceable, at least to me. Maybe I am wrong, but I've not yet noticed a vendor offering replacement bushings separately for its products. Clearly the product being described by Vitamin K is intended to have the bushings user-installed. Even if the user can't remove his bushings later without destroying the 3D-printed jig, that shouldn't be a problem if the 3D printed part can be cheaply replaced.

3. We have no real way of knowing how accurately any jig will perform until after we've paid (sometimes a 3-digit figure) for it. Our organization has several jigs at various price points and levels of quality in its toolbox; the extreme aluminum one (some consider it the "Cadillac" of such tools) has at least one rear bushing that visibly adds toe-in and thus can't be used. That kind of discovery wouldn't sting as much for a jig where the price was 1/3 or less…

4. A 3D printed jig might support angles other than the typical 0 and 3 degrees, if somebody wanted to experiment with that. (Hey, why not print one that already has a bit of built-in toe for the DFW?) If you can get replaceable inserts for different diameter drill bits, then one could have multiple jigs for different drill-bit sizes because the printed jig is cheap enough...

5. I'd be more comfortable letting others borrow a cheaper jig (or two, or three) for workshop usage. If they broke off the drill bit in the block or wrecked one of the bushings, I could salvage the others bushings and install them in the new jig. I could have spare jigs in case one turned up missing. And so on...

Question: do the bushing ports and block mating surfaces of a 3D printed jig still need to be machined to maintain accuracy? That could drive up the cost, and thus, the feasibility.
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Re: A 3D printed Drill Guide...worthy idea or not?

Post by FatSebastian »

whodathunkit wrote: Wed Mar 01, 2023 8:53 pmAnd the one thing I see the most that flat out damages the jig's .. is if your using the wrong drill bit size for the jig.
I'll add that using a high-speed power drill increases the potential for premature wear-out. If one uses a pin vise to drive the drill bit, then the user can feel when something is amiss, and hand-strength should rarely overwork the tool or block.
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Re: A 3D printed Drill Guide...worthy idea or not?

Post by whodathunkit »

FatSebastian wrote: Fri Mar 03, 2023 1:50 pm
whodathunkit wrote: Wed Mar 01, 2023 8:53 pmAnd the one thing I see the most that flat out damages the jig's .. is if your using the wrong drill bit size for the jig.
I'll add that using a high-speed power drill increases the potential for premature wear-out. If one uses a pin vise to drive the drill bit, then the user can feel when something is amiss, and hand-strength will rarely overwork the tool or block.
Yes you are so right FS ,
(Not to go off topic here about pen vise's)
I myself personally don't like using power drills in the axle jigs for the very reasons you have just described above.

However as you have pointed out .. A good pin vise has always been my go to as well.
I tend to stay away from the small diam handle type pen vises with the small collet type chucks for drilling axle holes with the jigs.
( I find them somewhat harder to tighten the drill bit down on .)
When I have to stop and brake out the pliers just to tighten down the collet chuck from the drill bit slipping when twisting and drilling in to a block.
It gets aggravating also.. when the drill bit slips out of the collet type pen vise:
When you are half way into your drilling and then have to re chuck it up while the drill bit is in the jig and car block.. or to use pliers to pull the drill bit out.

So personally I like using the pen vise types with the drill chuck end's like what's seen in the image and that I also linked below .
Image
https://www.amazon.com/General-Tools-93 ... 5598&psc=1
https://www.amazon.com/dp/B08M3GRNLR/re ... s9dHJ1ZQ==


When it comes to having a few different pen vise.. Sure I have a few different types for model making and scroll sawing projects and so on.
(Seen in the pic below)
From pencil handle types and double ended types seen to the left hand side, push spring twist drill type seen the middle, and swivel head and round head types on the right hand side.
Image

The black handle and drill chuck pen vise seen at the very top of the pic is one of my home made go to.. pen vise's that I use most for drilling axles holes with the jigs.
The drill chuck is from an old black and decker cordless screwdriver / drill that has a 1/4'' hex shank the handle is from a stubby 4 in 1 screwdriver.
Image
It's easier for me to tighten the drill bits down with the drill chuck and on my hands to grip and use now or days.

As for 3D Printing:
I don't know much about it's filament types.. how strong or flexible the 3d printed filaments are or if there prone to warping over time.
But I would think that the 3d print filaments would have a low coefficient of friction that would only allow short term use in contact with moving parts
So I would say the 3d drill jigs with out the drill bushings are only going to last you a very short time over those with the drill bushings installed.

However the 3d printed axle jigs with drill bushings are offered as a lower cost alternative for builders on a budget.. over the higher end axle jig models.
And then there is this type of 3d printed jig I'll link to the topic.
https://www.printables.com/model/363664 ... -drill-jig

FS and VK, looking back to when I first started posting here on DT in 2009.
I can recall a topic on about a flat bar adjustable axle jig with set screws for camber that was made from Pine Pro and also one made by Superior tool.
https://www.derbytalk.com/viewtopic.php ... jig#p49913

Pine pro jig was made of aluminum.
https://www.propshophobbies.com/product_p/ppr10210.htm
And the jig from Superior tool was made out of cold rolled steel.
https://www.worthpoint.com/worthopedia/ ... e-75244549
Image
The Jig from Superior tool is what I had and used back then.. when I look at the many axle jig types that are offered for the hobby today..
That offers better accuracy in drilling and ease of use for the builder.. it's a far better cry then the older alternatives of back in the day that were harder for the user to set up right.
So it's good to see that the axle jig tools for the hobby are evolving as well.
What type of automobile can be spelled the same forwards & backwards?
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