Any recommendations for car design? Help appreciated...

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whodathunkit
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Any recommendations for car design? Help appreciated...

Post by whodathunkit » Mon Feb 27, 2017 12:20 pm

Does your Ryobi scroll saw have the inserted throat plate as well?
Sometimes these have large gaps around the blade.
And if the thin middle is not supported bottom
side between to large openings.
The pressure of the blade cutting on the down stroke will crack the wood as well.

Don't know if this was your problem!
But to fix it so it's not make a thin table top cover
that will close up the gaps around the blade.


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What type of automobile can be spelled the same forwards & backwards?

derbypain
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Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Mon Feb 27, 2017 4:32 pm

Whoda, It does have a throat plate and it is a fairly large gap around the blade (well over an inch on each side of the blade for movement). I will try to add a photo of it later. I am sure even though the blade is tight that it still has side to side moving room especially if someone is getting impatient and applying too much pressure.

Since you don't have my exact saw some suggestions I am requesting may be contingent but:

* What type of materials have you made your attachment to reduce the gap size (wood, metal, lexan etc.) and how did you attach it to the bottom of the scroll saw table?

* How big of a gap would you recommend for your thin blades for the attachment to reduce gap size?

* How fast on the small thin blades do you run your variable speeds? This Ryobi has speeds of 550 to 1650 rpms.

Lastly and this is out to any and everyone....What target weight for the actual pinewood remaining after all the removal are you going for? Based on current design we are currently looking to be at .35 oz or 10 grams. Does that sound about right? This does not include a full 1/64" plywood bottom, photopaper top, fenders or balsa wood ladders just pinewood with all the holes in it.



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Re: RE: Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Mon Feb 27, 2017 4:33 pm

derbypain wrote:Whoda, It does have a throat plate and it is a fairly large gap around the blade (well over an inch on each side of the blade for movement). I will try to add a photo of it later. I am sure even though the blade is tight that it still has side to side moving room especially if someone is getting impatient and applying too much pressure.

Since you don't have my exact saw some suggestions I am requesting may be contingent but:

* What type of materials have you made your attachment to reduce the gap size (wood, metal, lexan etc.) and how did you attach it to the bottom of the scroll saw table?

* How big of a gap would you recommend for your thin blades for the attachment to reduce gap size?

* How fast on the small thin blades do you run your variable speeds? This Ryobi has speeds of 550 to 1650 rpms.

Lastly and this is out to any and everyone....What target weight for the actual pinewood remaining after all the removal are you going for? Based on current design we are currently looking to be at .35 oz or 10 grams. Does that sound about right? This does not include a full 1/64" plywood bottom, photopaper top, fenders or balsa wood ladders just pinewood with all the holes in it.
Image

Image

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whodathunkit
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Re: Any recommendations for car design? Help appreciated...

Post by whodathunkit » Mon Feb 27, 2017 9:32 pm

Here you go derbypain,
The area where i find this type of throat plate to flex at the most is in the area where i'm placing my finger tip in this pic.
And as you see there is some scarring on my scroll saw throat plate as well.. I call this the nature of the beast from learning the saw.
So don't fell bad about feed rates and pushing to hard to make a cut! ( just look at mine and get a good :rofl: )
Image
What I am talking about when making a table top plate cover is using something like 1/8 masonite to go over the top of the throat pate.
It does not have be anything super fancy just something made from thin material that the wood can slip on and to close up the gaps around the blade.
I made this one really quick after seeing your reply tonight.. ( it's not my best looking table top cover!)
However all you really need to do for closing the gaps.. is to drill a hole for the blade to pass threw and to tape it down so it will not move around.
As the blade cuts on the down stroke in thin areas you'll have better support bottom side of your work to keep it from pushing down.
Image

I know what your saying about the side to side movement in the cut.. the feed rate.. or the twisting to hard to make a quick corner as well.
Give it time and you'll master it !
I find that it will help to make quick corners if you round over the back side of the blade.
To do this.. with the saw running take a file or hone to the back side of the blade. (Before you start cutting!) any openings.
this will help you to twist the blade inside the cut with out splitting the wood out.
The square edge on back side of the blade is removed by doing this.
So the square edges can no longer dig into wood while turning but has a way to slip with in the cut with out catching.
You'll also find that most scroll saw blades will tend to drift and cut more so to the right while cutting..
this is due to the burs on the blade from stamping process when there made.

The weight you and your son are shooting for on the car body frame alone.. it sounds good to me guy's. ;)
Best of luck guy's & you'll get there it just take's a little time practice & patience on the scroll saw!


What type of automobile can be spelled the same forwards & backwards?

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Re: Any recommendations for car design? Help appreciated...

Post by Vitamin K » Tue Feb 28, 2017 10:32 am

Oh, nice idea about the table cover! My HF saw has a cheap little plastic piece that snaps in around the blade, and is never quite level with the aluminum saw table. Cannot tell you how many times I've snagged a workpiece there.



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Re: Any recommendations for car design? Help appreciated...

Post by whodathunkit » Tue Feb 28, 2017 12:24 pm

derbypain wrote: How fast on the small thin blades do you run your variable speeds? This Ryobi has speeds of 550 to 1650 rpms.

My DeWalt saw has 400-1750 strokes per minute.
On the variable speed dial the settings
I run around about a 3 to a 4 on the setting.
So I'm running the saw about mid range or so.
Sorry I missed this question last night!

Glade you like my table top cover idea as well
Vk .



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davet
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Re: Any recommendations for car design? Help appreciated...

Post by davet » Sun Mar 05, 2017 12:43 pm

We cut our block down to 3/8" thick or so then drill our holes. We then epoxy 1/64" plywood to the bottom with the grain opposite the block grain. We then router out our center section and weight pockets 1/4" deep. We finish by running the top on a belt sander until the whole thing 1/4" thick. This order has seemed to keep us from cracking or warping and puts our cubes 1/64" lower in the car.

-My question is if we start trying to build using the scroll instead of the router, will the epoxy cause problems with the blade?
-Should we cut out or body while it's still 3/8" thick or so then sand it down thinner?



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Re: Any recommendations for car design? Help appreciated...

Post by whodathunkit » Sun Mar 05, 2017 8:46 pm

davet wrote:-My question is if we start trying to build using the scroll instead of the router, will the epoxy cause problems with the blade?
-Should we cut out or body while it's still 3/8" thick or so then sand it down thinner?
As long as the epoxy is dry and not wet & sticky the scroll saw blades will cut right threw it with no problems!
wet and sticky epoxy will cause gumming problems of saw dust balling up and sticking to the blade!

My thoughts on belt sanding: If there is a thin wood band in between the openings for weight pockets..
you'll will run the risk of braking it out on a belt sander by thinning your body down afterwords.

:idea:
You could make a wooden sanding jig for holding the car body in.. if your cutting out the openings first and then sanding the car down to thickness.
For the holding jig it could be made something to the like of a lid that set's down over the car body..
with inserts for closing off the weight pockets and the openings.
This would also let you flip the car body over for.. top side or bottom side sanding and thinning of the car body..
& it might save on sanding down a finger tip or two on the belt sander.


What type of automobile can be spelled the same forwards & backwards?

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Re: Any recommendations for car design? Help appreciated...

Post by davet » Sun Mar 05, 2017 8:57 pm

After epoxying the plywood to the bottom we cut out the rear weight pockets 1/4" deep and epoxy in the 12 cubes. We let it cure then cut out the front weight pocket 1/4" deep and glue those 6 cubes in. We then cut the center down 1/4" deep from the bottom also. Next we belt sand the top until we start to see the tops of the cubes and the center section open up. We stop there. All of our routering is done from the bottom after the plywood had been put on. We never sand the bottom. I'm thinking that epoxy for the plywood is adding unnecessary weight.

My uneducated mind thought scroll saws were mostly similar. Now, with your help, I see there are some clear differences I would've only come across when I discovered it during use and after paying for one. Thank you for saving me time and money Whoda. :thumbup:



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Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Tue Mar 07, 2017 10:41 pm

Update: We have been able to get the car cut out and have attached the plywood bottom... The car seems super strong and does not appear warped. Without the plywood bottom it weighed about 9.9 grams or 0.35 oz... With the plywood added it brought the weight to 0.45 oz. Next we start working on the axles and wheels. I expect to get right at 4.0 oz of tungsten installed with wheels and cover. We were able to get a full 2.0 oz behind the back wheels using 1/4" tungsten cubes. My son and I are super appreciative to the details shared so far. We will keep you posted with more updates as they occur.

Question for you guys putting a cover on top of the car using glossy photo paper... How do you cut the paper to cover? Does it just cover the top or do you have the paper overlap the sides, front and back as well? Does it overlap to the bottom by a certain amount as well? We are trying to figure out the best way to transition the cover without having a bad look if we just have it covering the top and not going to the side or bottom.

How thick of photo paper are you using? If you don't know can you provide the brand and type of paper.

I know a bunch of detailed questions so thanks in advance for your time.

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Re: Any recommendations for car design? Help appreciated...

Post by davet » Wed Mar 08, 2017 1:19 am

We use Kodak premium photo paper, glossy. It shouldn't matter if glossy or not because you'll be clear coating it afterwards. Test your clearcoat on a test pic before you do anything else just to make sure it doesn't cause the ink to run. We used Rustoleum, glossy clear from Menards.



-We had an aircraft carrier car that was mostly gray with aircraft carrier surface as the top pic. We just painted the sides matching gray before putting the paper on.Image
-We had an American flag pic on one that we bent over the sides after the top cured. It folded over nicely but our top, outer edge of the body was slightly rounded, not a sharp 90. Notice the eagle's eye had to be lined up perfectly. The back of the BSA car is a separate piece cut to fit.ImageImage
-The car in our avatar is just the top but sides were painted matching blue and with a toothpick we extended the lightning bolts down the sides with white paint.Image

We size the pic to the car using the computer and print it on a test sheet of photo paper.Image
We held it up to the light and, on the backside of the paper, we put a tiny pen mark at each of the corners of the pic. We then lay the paper upside down on a table and placed our car, upside down on the pic and centered it inside the pen marks we made. Once centered, we connected the marks with pen (press lightly) so we had the outline of our body surface on the backside of the paper in the exact spot where the pic was oriented for the top of the car. We then cut out along the lines we drew. Cut about 5/16" wider than you need it on each side to give yourself a little wiggle room and also in case you want to wrap it over the sides.
Now flip it over and lay it on your car to see if it lines up how you want it and is long enough. Remember, if the nose slopes down, the top surface is slightly longer than 7". Here is where you can fold it sharply along the lines you drew then lay it on the car. Now the sides will bend over nicely and you can see if you like the look. If not, cut along the lines and don't wrap it over.

-Use 60 Minute epoxy so you can slide it around to get it lined up. This will really stiffen up the car also so we would sand down pretty thin, knowing this top cover would help strengthen.
-When putting the epoxy on the top of your body keep it very thin but cover the entire surface. Also, keep the glue about 1/16" from the side edges. Lay some tape along the edge and remove the tape once you get the glue on. This will prevent the epoxy from oozing out the sides when you put pressure on it. Lay the paper upside down and center the car on it. Flip it over and see that it's lined up. Flip it back over and hold it tight on a flat surface until it sets. DO NOT let your fingers touch the pic as it will ruin it. Use a soft rag to press down on pic along the edges if you have to.

Once all is on and cured, clear coat it with 2 very light coats, fenders and all. Let that dry and in a day or so you can polish with car polish.

-If using fenders we made them from balsa and printed a second pic and used portions of it to wrap the fenders. These we wrapped over the top and down the sides. These didn't always turn out as perfectly as we would've liked because the fender is curved.
-If using fenders I suggest gluing them on first. If you put the cover on first then glue the fenders on, some glue may get on the cover and mess up the ink. I got a call at work from my boy saying he ruined the car and we had to start over. He was gluing fenders on the LED car and got it on the top cover. Tried to wipe it off and had a mess. Belt sander took that cover off.



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Re: Any recommendations for car design? Help appreciated...

Post by Ignacious » Tue Mar 14, 2017 10:29 pm

Davet- 8 degrees on the DFW? Most recommendations I've seen is 1.5 and some 2? What is the benefit of such an extreme bend? And isn't that ridiculously hard to get the drift tuned in properly? We went with 2 degrees on the DFW this year just because our bender was incremented that way and it was insane trying to guestimate 1.5. There was a noticeable difference in tuning difficulty.



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Re: Any recommendations for car design? Help appreciated...

Post by Ignacious » Tue Mar 14, 2017 10:52 pm

We did our first ladder car this year using a scroll saw and a file. Drilled a small hole in each corner of each pocket to accommodate the turn. It worked fine. I have a tool that turns a dremel into a plunge router but the scroll saw and file was the easiest for the kid to use.



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Any recommendations for car design? Help appreciated...

Post by whodathunkit » Wed Mar 15, 2017 6:47 am

Sounds like a good idea and tip
For making it easy for kids to use the scroll saw and turn corners!




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Last edited by whodathunkit on Wed Mar 15, 2017 6:47 am, edited 2 times in total.


What type of automobile can be spelled the same forwards & backwards?

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Re: RE: Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Wed Mar 15, 2017 9:10 am

Ignacious wrote:We did our first ladder car this year using a scroll saw and a file. Drilled a small hole in each corner of each pocket to accommodate the turn. It worked fine. I have a tool that turns a dremel into a plunge router but the scroll saw and file was the easiest for the kid to use.
Exactly what we did for scrolling as well. Much easier for my son to scroll from drill hole to drill hole than try to turn a perfect corner. We are doing lower angles on dfw but only because of creating a four wheel rail rider due to district rules.

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