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Question about installing hard points for mounting

PostPosted: Sun Aug 14, 2011 10:37 pm
by atahoekid
I think I saw an answer for this somewhere in the real long thread but I couldn't find it when I looked for it. :? :? :?

I'm planning on installing things like porch lights, side markers, small indoor propane heater, etc. and want to install plywood hard points in the foam so I can securely mount all these things. I really don't want to have to cut all the way through the foam, I just want to flush mount the plywood.

What's the best way to cut out the shape to the right depth? I thought about using my router but there are 2 problems I can think of. 1) I suck at routing 2) The high speed of the router would burn not cut.

Any other suggestions?

PostPosted: Sun Aug 14, 2011 10:55 pm
by Wobbly Wheels
You could mark out the size of your ply piece and use a RO sander to take it down a bit. You'll need to fair the edges, but you'll likely be doing a bit of fairing anyway (I think Mike used spackle, I'm using epoxy). That's how I did the rebate for the window opening in the door.

Another idea that's been kicked around is through-drilling and gluing in a short chunk of dowel to take a single screw. That's probably the easiest for rectifying those 'oversights' that one forgets to include.

PostPosted: Mon Aug 15, 2011 12:32 am
by atahoekid
Thanks, food for thought :thinking: :thinking: :thinking: I may play with that one. The router too I guess... Maybe a smaller easier to control router would make things easier. HMMMM!!!, another excuse, err, reason to buy more power tools :twisted: :twisted: :twisted:

"UMHHHH, yeah, honey, I needed to buy another RO sander and another router cuz the ones I have are too big and too powerful... really, I swear!!! Ya gotta have the right tool for the job, if you want it to be right!!! Would I lie to you????

PostPosted: Mon Aug 15, 2011 12:58 am
by squatch
Routers work fine for shaping foam. Just remember to use old or cheap bits as foam destroys power tool blades and bits. You won't need good ones for foam but they'll never cut wood again. Also unlike wood there is almost no resistance to the router with foam. It's real easy to do too much. Can you say flying foam dust!

PostPosted: Mon Aug 15, 2011 5:30 am
by GPW
You don't need exotic tools to cut away foam ... when a serrated steak knife will do ... If you're insetting a plate , just cut around the outline and dig out the inside foam to the depth you want ... The Gorilla glue will fill in any imperfections ... If you're drilling a hole for a dowel , use very low speed ... and if you have to mount anything heavy , a dowel and plate combination might be better to spread the load out ...

related to hardpoint mounts

PostPosted: Mon Aug 15, 2011 7:04 am
by bonnie
Would this also work, if I wan t to make the foamie so that I can remove it from the trailer? I would like to have floor mounts and thought about using carriage bolts and hard mounting the pass through in the foam. That way the trailer can also be used to haul stuff. Another option I am considering is mounting tie down rings in the sides and single mount points aka the teal camper.

Which brings me to my third thought. Could I put solid tubes into a bracket and then mount caster wheels to the foamie to allow me to move it around easier when it's off the trailer?

thanks,

Bonnie

PostPosted: Mon Aug 15, 2011 8:50 am
by GPW
Bonnie , I'm mounting mine with bolts and Wing Nuts ... Removable !!! But mine is a unit , so for hauling , I'd need a separate floor , or no floor at all depending on the cargo ... and a lot of rope .. :o
We'll be pulling our Foamie inside soon for the finish work, no trailer ... It's so light , I'm just going to rest my cabin on some furniture dollies that I got on sale at HF ... doesn't take much ... and I can get inside too ... roll it out of the way when I need to ... :thumbsup:

PostPosted: Mon Aug 15, 2011 9:01 am
by Shadow Catcher
There are speed controllers that can be used with a router. I made my own using a fan speed controller from the big box. But the point that a sharp knife will work fine. You can also if you will be doing this a lot buy a hot knife i.e. http://www.craftershotknife.com HF has one for about 20$

PostPosted: Mon Aug 15, 2011 9:28 am
by GPW
http://www.rcgroups.com/forums/attachme ... id=4188577

Any shape you want ... :thinking: Watch the fumes ... :o

PostPosted: Tue Aug 16, 2011 7:37 pm
by pete42
GPW wrote:http://www.rcgroups.com/forums/attachmentNew.php?attachmentid=4188577

Any shape you want ... :thinking: Watch the fumes ... :o


When I was building my airplane a veri-eze foam and fiberglass by burt Rutan. we used a hot wire controled by a train transformer for the big cuts.
for small odd shape pieces we used a solder gun and 14 gage copper wire
practice on a piece of scrap but then again your won't be taking you foamy up to 10,000 feet either where a small mistake means more.

PostPosted: Wed Aug 17, 2011 9:30 am
by aggie79
Mel,

I think a router would work fine as to what you want to do. The trick is to use a guide bushing in the router and a template. As far as the router bit, I would try a spiral bit. If you can find one in high strength steel, that would be the one to get rather than than a more-expensive carbide bit.

There are many bushing/bit combinations, but for ease of explanation (and which is the setup I use) let's go with a 1/4" spiral bit and a 3/4" bushing. The bushing rides against the template - 1/4" material of your choice. This means the cutting edge of the bit is 1/4" away from the bushing. So, if you want a 3" round recess for a hardpoint, you'd need to make the hole in the template 3-1/2" in diameter (1/4" each side).

Set the template in place and fasten it somehow. On wood, I used double-sided tape to stick the template in place. Then set your bit depth and route away.

I wish I could describe things better in words. Please forgive me if you aready know how to do this technique.

Thanks,
Tom

Re: Question about installing hard points for mounting

PostPosted: Wed Aug 17, 2011 9:50 am
by eaglesdare
atahoekid wrote:I think I saw an answer for this somewhere in the real long thread but I couldn't find it when I looked for it. :? :? :?

I'm planning on installing things like porch lights, side markers, small indoor propane heater, etc. and want to install plywood hard points in the foam so I can securely mount all these things. I really don't want to have to cut all the way through the foam, I just want to flush mount the plywood.

What's the best way to cut out the shape to the right depth? I thought about using my router but there are 2 problems I can think of. 1) I suck at routing 2) The high speed of the router would burn not cut.

Any other suggestions?


while using the serated knife will and does work, its a pita! and takes a longer time.
i see nothing wrong with getting the new power tool to do the job faster and easier. i am always trying to tell hubby that same line. right tools for the right job.

Thread Hijack!

PostPosted: Wed Aug 17, 2011 2:32 pm
by jakie
OOOH a Burt Rutan design....VERY NICE!!!!!

PostPosted: Thu Aug 18, 2011 12:11 am
by atahoekid
aggie79 wrote:Mel,

I think a router would work fine as to what you want to do. The trick is to use a guide bushing in the router and a template. As far as the router bit, I would try a spiral bit. If you can find one in high strength steel, that would be the one to get rather than than a more-expensive carbide bit.

There are many bushing/bit combinations, but for ease of explanation (and which is the setup I use) let's go with a 1/4" spiral bit and a 3/4" bushing. The bushing rides against the template - 1/4" material of your choice. This means the cutting edge of the bit is 1/4" away from the bushing. So, if you want a 3" round recess for a hardpoint, you'd need to make the hole in the template 3-1/2" in diameter (1/4" each side).

Set the template in place and fasten it somehow. On wood, I used double-sided tape to stick the template in place. Then set your bit depth and route away.

I wish I could describe things better in words. Please forgive me if you aready know how to do this technique.

Thanks,
Tom


I'm thinking along the same lines, the template idea works just fine. I also got lucky the other day and found a small hand held trim router that I got from my dad's house as we cleaned it out and moved him into a home a few years ago.. At that time I got a couple of big boxes of tools. As amazing as it seems in my fuster cluck of a garage, I found it. so no need for a new tool.

I tried the template technique and it worked great, the router worked great and I used 2 part epoxy to glue the plywood in. I think the plywood will separate before the epoxy fails. Thanks for the two sided tape idea! Worked like magic.

Problem solved... Thanks Guys!!!!

:thumbsup: :applause: :applause:

PostPosted: Thu Aug 18, 2011 7:48 am
by GPW
Here's what I plan on using , Just a couple inside for lights ,fans, etc. Image