I need a new tiller crossbar for my gcat 5.7, finding a used one is probably unlikely. I think I'm just going to make my own. Any trick to getting it lined up properly and drilling holes in the right places?

Try the classifieds

Umm, measure twice, cut once? I guess?

--
Marty
1984 Hobie 16 Redline Yellow Nationals, "Yellow Fever"
Opelika, Al / Lake Martin
--

If someone could tell me the distance from center of tiller connecting bolt to center of tiller connecting bolt that would be helpful.

You need to purchase or re- use the adjustable end so you can make micro adjustments if needed
They sell them At murrays

Then u don't have to try and drill with the optimal tow

jalex

I need a new tiller crossbar for my gcat 5.7, finding a used one is probably unlikely. I think I'm just going to make my own. Any trick to getting it lined up properly and drilling holes in the right places?

Yes, you're right. I think a whole H16/17/18 crossbar would work.

This is the size tubing for the tiller crossbar on the legacy Nacras. Buy whatever length you need then drill it to suit. Or, measure the the GCat's tubing and find an exact match. It may not be anodized, but if your worried about that, buy two sticks. The shipping is the !@#$%@#$!@#$

https://www.speedymetals.…be-6061-t6-aluminum.aspx

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

jalex

Any trick to getting it lined up properly and drilling holes in the right places?

Measure twice and cut once for sure.

If drilling a round tube (or any metal part really), be sure to center punch before drilling. Otherwise the bit will wander and your hole will never be in the right spot. Using a drill press is best if you have one.

If you need to cut the tube with a hack saw, a trick to keeping the cut square is to use a hose clamp around the tube at your cut line. The hose clamp will act as a guide for your saw.

sm

I have one available in Atlantic Highlands, NJ. However, my advice would be to simply buy a similar sized aluminum bar (I've done this before) and cut to size, then place two holes in the correct location. You should be able to find the metal for $15 at a local metal supplier or maybe even at a big box store. Don't worry about anodizing because aluminum does not rust in salt or freshwater. It only corrodes when dissimilar metals are in contact with it.

I appreciate the responses. The aluminum is no problem, I am actually in the metal business. My question is, is there a trick to making sure the rudders are parallel to each other before I measure and drill.

I did a quick google search on G-cats and it looks like the typical tube used on most other beach cats. I bet if you got a Nacra crossbar with the adjustable end piece, it would make everything a whole lot easier.

Murrays has the adjustable end cap: https://www.murrays.com/product/56-5508/

Quote

My question is, is there a trick to making sure the rudders are parallel to each other before I measure and drill.

different age and style rudders may be a little different, optimal tow-in may be different boat to boat, gugions may also be slightly different boat to boat, rudder pin holes wear, etc

The holes you drill today, may not be optimal in the future for many reasons (replacement rudders, casting wear, etc)

that is why I recommended the adjustable end - sure it's more money, but it's a proven system

also mine have some rotational play (supposedly) to help with Ackermann steering geometry (edit - that was wrong, the play is on the tiller end)



Edited by MN3 on Jul 14, 2017 - 05:44 PM.

Quote

Don't worry about anodizing because aluminum does not rust in salt or freshwater. It only corrodes when dissimilar metals are in contact with it.

are rudder crossbar attachments alum ?




Edited by MN3 on Jul 14, 2017 - 01:44 PM.

I actually did this on a G-Cat 5.7. What I did was raise the rudders up and line each with the centerline of the boat. This works really well when the boat is on the ground, as the rudders won't swing. Then, I got some aluminum tubing, just like what came with the boat. Then I laid it down on the tillers and took a sharpie and drew marks for the holes. Then I drilled a small hole to establish the hole location. Then I drilled a larger one to accommodate the crossbar attachments.

The crossbar attachments are dissimilar from the crossbar alum and this may lead to some corrosion here, but I did not see it on my boat. Anodizing would not help as it would wear away here. This could be an added benefit of the adjustable sections MM3 mentioned, which are not metal.

Dogboy

If drilling a round tube (or any metal part really), be sure to center punch before drilling. Otherwise the bit will wander and your hole will never be in the right spot. Using a drill press is best if you have one.

Disagree on center punching aluminum tubing. Way to soft and the tube will crush. Here is a better way:

https://www.biggatortools.com/drill-guides.html

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

leeboweffect

Disagree on center punching aluminum tubing. Way to soft and the tube will crush.

You're kidding, right? How hard are you hitting the punch that you're crushing the tube?

I center punch aluminum (plate, tubing, whatever) all the time before drilling and it works just fine (as does the very seasoned machinist at our plant). This is SOP for drilling holes in metal.

sm

Still, that guide is a nice tool. Great way to keep bolt holes aligned in tubing. Wish I had one when I was drilling lotsa new holes in my catrax axel.

Thanks Leebow.

--
Prindle 18
96734
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Dogboy

You're kidding, right?

No, not kidding. You will crush/deform the tube slightly if you're center punching it. This is just thin wall 6061 aluminum tubing, not boiler plate.

Dogboy

I center punch aluminum (plate, tubing, whatever) all the time before drilling and it works just fine (as does the very seasoned machinist at our plant). This is SOP for drilling holes in metal.

For hand work (accuracy +- 0.010") OK on plate and/or flat stock, but NEVER on round stock. A "seasoned" machinist would never use a center punch (very cave man way to do it) to locate a hole on round stock as it would end up way off center unless dumb luck is on your side. The v block I suggested above is the best way I've found to do it accurately with hand drill. If you have machine tools here are a couple of unsophisticated ways to do it:

https://www.youtube.com/watch?v=eUTWtHOVyPI

https://www.youtube.com/watch?v=JRJOtQNV8RU

A machinist with a complete shop would not use any of the methods above if maintaining the center line is critical which it is on these parts. Old school would use a vertical mill with dial indicators on magnetic bases, moving in to the late 1970's would be a vertical mill with digital units and most current a CNC.

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

leeboweffect

Dogboy

You're kidding, right?

No, not kidding. You will crush/deform the tube slightly if you're center punching it. This is just thin wall 6061 aluminum tubing, not boiler plate.

Dogboy

I center punch aluminum (plate, tubing, whatever) all the time before drilling and it works just fine (as does the very seasoned machinist at our plant). This is SOP for drilling holes in metal.

For hand work (accuracy +- 0.010") OK on plate and/or flat stock, but NEVER on round stock. A "seasoned" machinist would never use a center punch (very cave man way to do it) to locate a hole on round stock as it would end up way off center unless dumb luck is on your side. The v block I suggested above is the best way I've found to do it accurately with hand drill. If you have machine tools here are a couple of unsophisticated ways to do it:

https://www.youtube.com/watch?v=eUTWtHOVyPI

https://www.youtube.com/watch?v=JRJOtQNV8RU

A machinist with a complete shop would not use any of the methods above if maintaining the center line is critical which it is on these parts. Old school would use a vertical mill with dial indicators on magnetic bases, moving in to the late 1970's would be a vertical mill with digital units and most current a CNC.

When I read this I had to scratch my head and go fix a double bourbon. There is no way a center punch like these are going to crush/deform AL tubing.
http://www.homedepot.com/…r-Punch-70079H/206007134
https://www.harborfreight…ed-center-punch-621.html

--
Philip
--

P.M.

When I read this I had to scratch my head and go fix a double bourbon. There is no way a center punch like these are going to crush/deform AL tubing.
http://www.homedepot.com/…r-Punch-70079H/206007134
https://www.harborfreight…ed-center-punch-621.html

Most folks have never seen a spring loaded "automatic" center punch. The old punch in left hand, hammer in right hand smack it method prevails in home shops. Agreed the "automatic" type wouldn't crush the tube, but it will not help with centerline accuracy as the drill guide will.

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

Good to know we still all know how to scratch our heads and go find the appropriate alcohol for the remaining itch. It is also good to know what the best practices are, whether or not we have the tools and wherewithal to use them (I had to look up how to spell wherewithal could be that itch thing )

--
dg
NACRA 5.2 #400
This End Up
Original owner since 1975
--

leeboweffect

P.M.

When I read this I had to scratch my head and go fix a double bourbon. There is no way a center punch like these are going to crush/deform AL tubing.
http://www.homedepot.com/…r-Punch-70079H/206007134
https://www.harborfreight…ed-center-punch-621.html

Most folks have never seen a spring loaded "automatic" center punch. The old punch in left hand, hammer in right hand smack it method prevails in home shops. Agreed the "automatic" type wouldn't crush the tube, but it will not help with centerline accuracy as the drill guide will.

Well this has been a fun lesson. Maybe if the operator of said hammer doesn't have the skill set or common sense to not Beat the Helll out of soft aluminum tubing, than maybe he does not belong in the DIY arena.
All the same, the bourbon was excellent.

--
Philip
--

The point is, you need to use some method of locating the drill and keeping it on the mark. If you just try to drill directly onto the tube, the bit will wander all over the place. I have used a center punch on tubing countless times and it has worked fine for my needs on Hobie repairs. We are not talking aircraft parts here needing four deimal place precision, get within 10-20 thousanths and you're fine.

sm

P.M.

All the same, the bourbon was excellent.

+1

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

I made my crossbar with 3/4" & 1" schedule 40 aluminum pipe.
The 3/4" sleeves into the 1" just right. I used pointed Allen key set screws to secure the 3/4" inside the 1".
http://www.sailrite.com/Drill-Steady-Tubing-Tool
I used a home made version of the item linked above for the drill guide.
You can find ground clamps of various sizes at your local electrical supplier.

--
'82 Super Cat 15
Hull #315
Virginia
Previously owned: '70 H14, '79 H16, '68 Sailmaster 26, '85 H14T
--

Quote

When I read this I had to scratch my head and go fix a double bourbon. There is no way a center punch like these are going to crush/deform AL tubing.
http://www.homedepot.com/…r-Punch-70079H/206007134

+1
I've had those for years. They are the only way to mark something when you need to do it insitu.

--
Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
--

So now I have a huge tool (don't go there!) shopping list plus the Bourbon. I hate to go cheap on either one.

--
'82 Super Cat 15
Hull #315
Virginia
Previously owned: '70 H14, '79 H16, '68 Sailmaster 26, '85 H14T
--