routers and templates or patterns

Anything to do with mechanical, construction etc

routers and templates or patterns

Postby QueticoBill » Sat Dec 17, 2016 11:03 am

I'd like to build a woody, using a profile close to the "new cub", and would like to cut walls and trim with a router. I plan to make a template of mdf and I'd like to cut "concentric" versions or inner and outer walls, hatch, and especially hardwood trim. I thought I'd make template based on stock router base and smallest piece - inside or bottom of hardwood trim - and for larger cuts, make larger round router bases. I never for a second thought this was a new idea so went googling and can't find anything on doing this. Lots of different sub bases - but none that would follow a template on this scale as precisely as a round sub base on the router. Certainly someone here must have done this. And I strongly prefer the precision I can achieve with a router over a jig saw (which along with a sander is what I would have to use to cut template - unless I can use someone's shopbot.
QB
A tear with no name: viewtopic.php?f=50&t=67624
QueticoBill
Silver Donating Member
 
Posts: 1183
Images: 22
Joined: Sun Apr 14, 2013 7:22 am
Location: Clayton NY

Re: routers and templates or patterns

Postby tony.latham » Sat Dec 17, 2016 1:10 pm

QueticoBill wrote:I'd like to build a woody, using a profile close to the "new cub", and would like to cut walls and trim with a router. I plan to make a template of mdf and I'd like to cut "concentric" versions or inner and outer walls, hatch, and especially hardwood trim. I thought I'd make template based on stock router base and smallest piece - inside or bottom of hardwood trim - and for larger cuts, make larger round router bases. I never for a second thought this was a new idea so went googling and can't find anything on doing this. Lots of different sub bases - but none that would follow a template on this scale as precisely as a round sub base on the router. Certainly someone here must have done this. And I strongly prefer the precision I can achieve with a router over a jig saw (which along with a sander is what I would have to use to cut template - unless I can use someone's shopbot.


I've built three teardrops, all using a pattern. I can't imagine building another without using one. I use 1/4" plywood sub flooring for my patterns. No voids. I would think that using a 8' or 10' long MDF pattern may fail. Here's my wife working on her son's 'drop:

Image

I cut my parts to within 3/16" with a saber saw and then use the pattern and flush trim bit to flush cut the parts. :thumbsup:

Tony
User avatar
tony.latham
Gold Donating Member
 
Posts: 6880
Images: 17
Joined: Mon Jul 08, 2013 4:03 pm
Location: Middle of Idaho on the edge of nowhere

Re: routers and templates or patterns

Postby KCStudly » Sat Dec 17, 2016 1:22 pm

I think I understand the question. Essentially you want to make one template matching the inner wall skin and then step off of this equally using what amounts to custom made collars of different diameters mounted to your router shoe/base plate. The shoes would be the correct diameter to place the cutter edge at profiles matching your outer skin and inside step of your profile trim.

That sounds very doable, but if you are looking for a high degree of accuracy for the stepped parts (...not sure why you would it...) you might want to make the collars on a lathe with concentric steps that fit into the opening in the router base. If the collars aren't round and aren't mounted concentrically with the cutter, as you rotate the router in the course of following the template you can get some variation. Yes, if your collars aren't perfect, keeping the router oriented the same relative to the template would help, and just how accurate you need to be is up for debate, just saying.

Sounds like it would work fine, but I wonder if it is less work than just cutting your template down incrementally for each stage of the process (what most people do).
KC
My Build: The Poet Creek Express Hybrid Foamie

Poet Creek Or Bust
Engineering the TLAR way - "That Looks About Right"
TnTTT ORIGINAL 200A LANTERN CLUB = "The 200A Gang"
Green Lantern Corpsmen
User avatar
KCStudly
Donating Member
 
Posts: 9609
Images: 8169
Joined: Mon Feb 06, 2012 10:18 pm
Location: Southeastern CT, USA
Top

Re: routers and templates or patterns

Postby QueticoBill » Sat Dec 17, 2016 2:13 pm

KC - yes - but was thinking 3/4" mdf and able to do it all on trailer floor as work table. I imagined going back and forth from "sizes", in particular for wood trim applied after wall (think rail and stile paneling) and the hatch. I didn't think it would be too hard to make the bases and center them on the collet with a centering pin or cone. Basically big guide bushings.

Thanks.
QB
A tear with no name: viewtopic.php?f=50&t=67624
QueticoBill
Silver Donating Member
 
Posts: 1183
Images: 22
Joined: Sun Apr 14, 2013 7:22 am
Location: Clayton NY
Top

Re: routers and templates or patterns

Postby noseoil » Sun Dec 18, 2016 9:11 am

In tooling, we used bits with interchangeable pilot bearings. A 1/2" flush-cut bit (bearing on the bottom of the shaft) can have a 3/8" or 3/4" bearing swap, so you end up with a perfectly stepped cut every time. A router is the way to go for this setup. Also, I recommend a "plunge" type base, not a screw base, for doing any tooling. The plunge base can be used with a "feeler gauge" by simply zeroing the cutter at the bottom, then using the thickness of material for the pass as the depth gauge. Much quicker for setups & consistency.

You still have to make a pattern, but once it's finished, repetitive cuts & precision are guaranteed & cutting time is greatly reduced. MDF works pretty well for a pattern, but watch your thickness & web width, so there isn't too much lateral movement when screwing it in place. It can flex a bit when leaned on with lateral loads. Keep some bondo handy as well, you might nip a corner or something on the pattern & bondo works pretty well for fixing small dings or chips in the wrong place. Just sayin'.....
Build log: viewtopic.php?f=50&t=60248
The time you spend planning is more important than the time you spend building.........

137905
User avatar
noseoil
1000 Club
1000 Club
 
Posts: 1820
Images: 669
Joined: Sun Apr 27, 2014 8:46 am
Location: Raton, New Mexico, living the good life!
Top

Re: routers and templates or patterns

Postby QueticoBill » Sun Dec 18, 2016 9:26 am

I am trying to get a 3 or 3 1/2" difference from same template/pattern. That's why the guide bearings don't work.

I do wonder if a couple of "pins" in the base to follow the template would work, at least for "outside" cuts.
QB
A tear with no name: viewtopic.php?f=50&t=67624
QueticoBill
Silver Donating Member
 
Posts: 1183
Images: 22
Joined: Sun Apr 14, 2013 7:22 am
Location: Clayton NY
Top

Re: routers and templates or patterns

Postby KCStudly » Sun Dec 18, 2016 4:40 pm

The pins will get you close, but might lose a little accuracy on tighter radii. Tangent to tangent round collars will be more exact... if that matters to you.
KC
My Build: The Poet Creek Express Hybrid Foamie

Poet Creek Or Bust
Engineering the TLAR way - "That Looks About Right"
TnTTT ORIGINAL 200A LANTERN CLUB = "The 200A Gang"
Green Lantern Corpsmen
User avatar
KCStudly
Donating Member
 
Posts: 9609
Images: 8169
Joined: Mon Feb 06, 2012 10:18 pm
Location: Southeastern CT, USA
Top

Re: routers and templates or patterns

Postby aggie79 » Tue Dec 20, 2016 11:34 am

Although my teardrop is not a woody, I did something similar to what I think you are wanting to do to create a 1/4" MDF template to layout cuts and as a router template to cut the plywood "framing" for my sidewalls. 1/4" MDF works well as a template because it is typically 1" longer and wider than standard sheet goods. This is a picture of the template on top of 3/4" MDO plywood:

Image

To answer your question about maintaining a parallel cut around the curved perimeter and other radius cuts, this is how I made my template. First, I drew a 3" grid. Then I started to draw the perimeter. For the straights, I marked all of the exterior straight lines on the perimeter and their starting and ending points. Then I marked the interior straight lines at the offset that I wanted. I did not mark the starting and ending points of interior straight lines. Next I started laying out the exterior curves and radii. For the radii, I used a home-made compass/trammel to mark the exterior radii and interior radii (at the desired offset). I drew the radii beyond their intersection with other curves/radii.

This is how I drew the exterior perimeter curves for the "non-radius" other curves, I eye-balled the curve and used a batten and hard points held with double-sided tape. I moved the hard points around until the curve was looked right and the starting and ending points were tangent - blended smoothly - with the previously drawn straight lines and radii.

Image

To draw the interior curves, I made a home-made version of this scribe tool: https://www.amazon.com/M-Power-Perfect-Butt/dp/B001BLX1GM. I don't remember my offset distance, but I think it ended up being about 3" - 3-1/4". To make the tool I used a 3-1/2" hole saw and cut a "round" in 3/4" plywood. I believe the hole saw has a 1/4" pilot hole. Whatever diameter it was, I wrapped tape around a pencil until it was just snug. Then, using the tool against the batten, drew the offset interior curves. (Intermittently I removed a hard point and/or blended in the line to make a continuous line).

To cut the template, I rough cut near to the lines using a jig saw. I then used a sander and/or hand-sanded to the lines for the finish cut.
Tom (& Linda)
For build info on our former Silver Beatle teardrop:
Build Thread

93503
User avatar
aggie79
Super Duper Lifetime Member
 
Posts: 5405
Images: 686
Joined: Tue Aug 07, 2007 5:42 pm
Location: Watauga, Texas
Top

Re: routers and templates or patterns

Postby QueticoBill » Thu Dec 22, 2016 5:05 pm

Straights? I have no straights. All ellipse. :)
QB
A tear with no name: viewtopic.php?f=50&t=67624
QueticoBill
Silver Donating Member
 
Posts: 1183
Images: 22
Joined: Sun Apr 14, 2013 7:22 am
Location: Clayton NY
Top

Re: routers and templates or patterns

Postby AZ_Desert_Rat » Tue Dec 27, 2016 11:41 pm

QueticoBill wrote:I am trying to get a 3 or 3 1/2" difference from same template/pattern. That's why the guide bearings don't work.

I do wonder if a couple of "pins" in the base to follow the template would work, at least for "outside" cuts.


Hi QueticoBill,
I have been catching up on my reading and caught your question and the ideas posted... I realize this is an older thread, but in case you are still working on ideas or someone else is interested... Here is my 2 cents... :thinking:

To adapt the same baseplate to the various profile differences you mention:

1-- I would probably first make a Plexiglass/Lexan baseplate (I like to see what's going on) and then...

2-- Cut a set of "donuts" (Oversized guide bushings) to match the different profiles needed, probably cut out of the same material used for the baseplate, using different size holesaws (I suggest use of a drillpress or lathe, but if careful, a hand-drill should get you close enough)...

3-- Once the outside diameters are all cut, using a bolt as the center axle, chuck each in a drillpress/lathe/hand-drill chucked in a vise and fine tune the outer diameters...

4 -- Establish a common-diameter bolt circle that can be used on all "donuts" (BEFORE the center hole is expanded using a holesaw, to be done later) and drill three equally spaced holes in each "donut" OUTSIDE the holesaw diameter to be used in 6-- below, and countersink for matching screws...

5-- Drill three holes and thread in the baseplate to match the locations in the "donuts"...

6-- NOW, using a holesaw, cut the center hole to allow room for the router bit...

7-- Using three screws of the correct size and length, attach the appropriate "donut"/Guide Bushing needed...

Anyway, I would probably do something like this if I wanted to use a common template to cut progressively larger profiles... See the very rough quick sketch of one of the "donuts".... Remember the Profile to Pattern distance is from the router bit to outer diameter of your "donut"/Guide Bushing...

Good luck and this is just and idea for thought...
Attachments
Home-made Guide Bushing.jpg
Home-made Guide Bushing.jpg (4.61 KiB) Viewed 1111 times
Happy Camping & Building,
John (JC)


Image

Image
The Arizona Desert Rat 6x10' Cargo Conversion

Image
The FunFinder a 19' Toy Hauler

An AZ Desert Transplant
Gallery: gallery/album.php?album_id=3168
User avatar
AZ_Desert_Rat
500 Club
 
Posts: 553
Images: 55
Joined: Sun May 12, 2013 12:17 pm
Location: Zimmerman, Minnesota
Top

Re: routers and templates or patterns

Postby Louisd75 » Mon Jan 02, 2017 10:45 pm

As another possible option, take a look at the Milescraft Base plate/bushing set. The clear base screws into the bottom of your router and you use interchangeable bushings. You may not even have to remove the router bit to change bushing sizes if your bit is small enough:

https://www.milescraft.com/product/baseplatebushingset/

Image
Louisd75
Teardrop Master
 
Posts: 106
Images: 209
Joined: Wed Jul 17, 2013 4:27 am
Location: Bellingham WA
Top

Re: routers and templates or patterns

Postby QueticoBill » Tue Jan 03, 2017 8:22 am

Good concept but I'm looking for up to 3 1/2" offset, and this is not 1/2".
QB
A tear with no name: viewtopic.php?f=50&t=67624
QueticoBill
Silver Donating Member
 
Posts: 1183
Images: 22
Joined: Sun Apr 14, 2013 7:22 am
Location: Clayton NY
Top

Re: routers and templates or patterns

Postby AZ_Desert_Rat » Tue Jan 03, 2017 5:33 pm

Hi Bill,
I don't know of anyone that makes the size bushings you want and the suggestion I previously made would be an easy way to go; the bushing diameter is only limited by your imagination and practicality... :shock:

I am not sure where you would need to follow a large or small radius, as the case may be, with progressively larger set of bushings (3-1/2" rad., we're talking a 7" plus the radius of the cutter bit)... :thinking:

Just another thought... a glue-up bent frame foamy... I prefer the aesthetics of curves and am considering building a TD or short Standee (Following the late forties or early fifties design shapes) next year for a charity project and still in the planning stages. All depends on permits, zoning for a garage and getting the garage built to house the project, and time. But more to the point, I have decided it would be to build a glue-up bent frame foamy with framing (studs and cross-members) as required for the roof, doors, windows, vent, accesses, penetrations, etc. and spray-foam all voids. Anyway, that's just another idea for you to mull over...
:twisted: :thinking:

Good luck on your build, I like the plans you have drawn and can't wait to see the build progress... :thumbsup:
Happy Camping & Building,
John (JC)


Image

Image
The Arizona Desert Rat 6x10' Cargo Conversion

Image
The FunFinder a 19' Toy Hauler

An AZ Desert Transplant
Gallery: gallery/album.php?album_id=3168
User avatar
AZ_Desert_Rat
500 Club
 
Posts: 553
Images: 55
Joined: Sun May 12, 2013 12:17 pm
Location: Zimmerman, Minnesota
Top

Re: routers and templates or patterns

Postby AZ_Desert_Rat » Tue Jan 03, 2017 5:47 pm

aggie79 wrote:Although my teardrop is not a woody, I did something similar to what I think you are wanting to do to create a 1/4" MDF template to layout cuts and as a router template to cut the plywood "framing" for my sidewalls. 1/4" MDF works well as a template because it is typically 1" longer and wider than standard sheet goods. This is a picture of the template on top of 3/4" MDO plywood: ...


You did a nice job on the template Aggie... :thumbsup: :thumbsup:
And of course, the trailer turned out equally as nice... great job... :applause:

Sorry to jump in on your thread Bill, but I had to comment on Aggie's template...
Happy Camping & Building,
John (JC)


Image

Image
The Arizona Desert Rat 6x10' Cargo Conversion

Image
The FunFinder a 19' Toy Hauler

An AZ Desert Transplant
Gallery: gallery/album.php?album_id=3168
User avatar
AZ_Desert_Rat
500 Club
 
Posts: 553
Images: 55
Joined: Sun May 12, 2013 12:17 pm
Location: Zimmerman, Minnesota
Top

Re: routers and templates or patterns

Postby QueticoBill » Tue Jan 03, 2017 8:18 pm

Not a problem AZ. I studied the pictures quite a bit.
QB
A tear with no name: viewtopic.php?f=50&t=67624
QueticoBill
Silver Donating Member
 
Posts: 1183
Images: 22
Joined: Sun Apr 14, 2013 7:22 am
Location: Clayton NY
Top


Return to Teardrop Construction Tips & Techniques

Who is online

Users browsing this forum: No registered users and 14 guests