PDA

View Full Version : Scratchbuilders sanding jig



gary60s
24th Feb 2012, 04:59 PM
To make a perfect 45 degree angle on wall edges, I made these blocks from solid oak. They are cut with a 45 degree angle on each, and put together with screws and wing nuts. To use, just clamp your wall between them, with edge sticking up the thickness of wall material, and then use a sanding block resting on one of the block edges. Sand just enough until you have a sharp edge on the wall. It gives a perfect 45 degree angle on the wall edge for very smooth wall joints. I thought about making these for sale on ebay, but anyone can make them easily.

Taylure (RIP)
24th Feb 2012, 05:16 PM
I shall be making this jig soon.

Kilroy
24th Feb 2012, 06:14 PM
Nice, Grey60s I too will give it a try

WP&P
24th Feb 2012, 07:33 PM
That looks cool, but if you were to offer them for sale, I'd wonder about the use of wood to form the slopes. I would assume that as you use these, the wood itself gets sanded down, potentially changing the angle. Maybe an improvement would be to attach a strip of brass to the face of the slope. Or, more like a plate of brass. Screw heads would tear up your sandpaper, so to attach it I'd suggest a plate with a 45-degree bend in it, so that you attach it to the blocks down below the slope. The portion resting on the slope would then have no interruptions, perhaps being held on just by a bit of epoxy.

gary60s
24th Feb 2012, 09:07 PM
I've had others mention that, but I'm not selling anymore, and the oak shows no signs of wear. Good sugestion though.

Jimmi (RIP)
24th Feb 2012, 11:12 PM
Great idea Gary. I'm going to make one myself. Thanks.

Michael Whiteman
25th Feb 2012, 12:21 AM
I think you could prolong the wood angle if you used a file initially. What a great idea for those who have a saw that can produce these pieces.

NellsChoo
18th Dec 2014, 04:52 PM
I was just looking online for some tool to help me make that 45 angle so I can use brick sheeting to make chimneys. The only thing I found were a miter box w/saw, but it wouldn't work. This is a nifty idea! Thing is, wouldn't the wood end up worn out from the sanding? WHAT IF this thing could be made of either a dense plastic or, even better, METAL! I'd buy one from Gary in a second!!!

Tred
18th Dec 2014, 05:41 PM
You know, it's a great idea! I think if you used a more solid wood, it might last a while. But in the mean time... What about using some aluminum (coke can?) glued down on both sides of the block? It's thin enough to work with, and it won't wear as fast as the wood alone. I might just give it a try?

NellsChoo
18th Dec 2014, 06:09 PM
Hmmm, as long as the angle is still right, right?? ;)

Jazzbass01
18th Dec 2014, 06:20 PM
Let's not reinvent the wheel... Oak is pretty hard and dense, it should last a long time..

Jugtown Modeler
18th Dec 2014, 06:31 PM
You don't even need to sand using a jig like this.
Once clamped in, the form makes a good edge to run a knife blade along. With the blade flat against the wood, the sharpened edge does not touch the wood surface. Depending on the thickness of the plastic, it might take several passes or a "rough pre-cut" to get it done.

Great little item. I have used many a similar jig to create various roof angles for architectural model projects. We used double sided tape to temporarily hold a piece in place. The angled jig blocks would be used in small table top saws or disc sanders or knifes to create the actual angels to miter roof line joints.

gary60s
18th Dec 2014, 09:45 PM
Interesting suggestions for improvement. While they all have merit you would be spinning your wheels. If you can't cut the pieces, find a friend with a table saw. I first made these about a year before I wrote the post. And since that time I've used them for over 40 bevels and they still SHOW NO SIGNS OF WEAR. Not even a scratch. Oak is some tuff wood. Small project pieces can be obtained at home improvement places.

NellsChoo
19th Dec 2014, 03:45 PM
So... Gary........ how much for one??? >:-}

dick green
19th Dec 2014, 04:09 PM
I don't know why every is trying to improve a tool That works just fine takes 15 minutes to make and cost maybe a buck. I made a very similar jig years ago for shooting miters with a block plane. When making wooden boxes. Mine is maple cause that's what I had at the time. Garry's jig as designed and built will last the average modeler a long time.

I have built several of your designs. I found them well thought out and nicely presented

I for one thank you Gary for taking the time to pass this information along without and expectation of remuneration.

Dick

ChicagoNW
19th Dec 2014, 06:16 PM
Every time you rub sandpaper to wood you remove some. You may not see a lot of wear but is is there.

Many of us use stainless steel rulers for straight edge, while cutting with an Xacto. But with each pass you remove some of the metal. With the amount of cutting that's done in the hobby you'll notice it in about ten years. But when I did paste up at newspapers and I was cutting ten hours an day five days a week. We'd put a razor edge on a stainless ruler in months. If you drew a line with that ruler and laid a new one on the line you'd see the curve too. It happen all the time. Only doing layout on computers stopped the wear on the rulers.

Sanding, scraping or cutting all remove material from everything, always.

baronjutter
19th Dec 2014, 06:54 PM
I need to make one of these too, or something similar! Is there a way to make a sort of jig or method to sand 90 degrees perfectly to make sure ends are perfectly square?

gary60s
19th Dec 2014, 10:29 PM
I need to make one of these too, or something similar! Is there a way to make a sort of jig or method to sand 90 degrees perfectly to make sure ends are perfectly square?

Take a look at the picture again. You will see that the bottom of the jig is flat. There is your 90 degrees !

ChicagoNW
20th Dec 2014, 01:28 AM
Sometime the solution is so simple we can't see it.

NellsChoo
23rd Dec 2014, 12:15 PM
... sometimes we are simply BLIND! :l:

gary60s
6th Jan 2015, 12:59 PM
I thought I had included the sketch showing dimensions for making this tool. For those of you that have a table saw, or know someone that has one, use the sketch to make the parts, then assemble. For more information, see the first post in this thread.

http://www.nscale.net/forums/attachment.php?attachmentid=65685&d=1420566850

NellsChoo
6th Jan 2015, 03:28 PM
GARY - wellp, I tried to use the device, and things didn't go well. I was afraid to say it... No matter what I did, the edge of the styrene would not stay straight or be at the correct angle. I will try again with a straight blade and see if that helps. As for everyone saying the oak will hold up just fine, IT DIDN'T. If this could be machined out of aluminum, I can see it being easier to use.

I don't know just what it is I am doing wrong, but it sure looks like it should work!!!!

gary60s
6th Jan 2015, 04:53 PM
GARY - wellp, I tried to use the device, and things didn't go well. I was afraid to say it... No matter what I did, the edge of the styrene would not stay straight or be at the correct angle. I will try again with a straight blade and see if that helps. As for everyone saying the oak will hold up just fine, IT DIDN'T. If this could be machined out of aluminum, I can see it being easier to use.

I don't know just what it is I am doing wrong, but it sure looks like it should work!!!!


Did you put a piece of scrap at the bottom before tightening? (maybe you missed it, but I told you that in chat. It keeps it aligned correctly like I mentioned). If you wore out the oak in one attempt, and I couldn't in 40, you must be using coarse sandpaper. I used fine emory board and made sure that the block separation distance was the same at top and bottom. It always worked flawlessly for me. Go gently into the workshop...lol.

gary60s
6th Jan 2015, 05:03 PM
Wait...did you say "straight blade" ??? I did NOT design this tool to be used for CARVING OR CUTTING the workpiece. SANDING ONLY.

NellsChoo
6th Jan 2015, 05:10 PM
Yeah, somehow I thought you were going to say that... Thing is, I had some trouble sanding without the metal hardware getting in the way. The styrene brick sheets I have are so darn THICK... I need to reset, rethink, and try again...

gary60s
6th Jan 2015, 05:28 PM
http://www.nscale.net/forums/mysmiliesvb/mysmilie_1017.gif You may need a revised super heavy duty industrial version with 1" bolts and 100lbs of torque.

NellsChoo
6th Jan 2015, 05:50 PM
Before things went wrong:

65696 65697

Jugtown Modeler
6th Jan 2015, 06:11 PM
Did you put a piece of scrap at the bottom before tightening?

I am guessing/assuming but do you mean a scrap of the same material used to keep the space between jig halves consistent...?

Nells... if the part moved. this might be he cause.


I did NOT design this tool to be used for CARVING OR CUTTING the workpiece.

Gary, I recomended the blade idea... By taking a flat blade and holding it against the hard wood surface, you can trim some plastics to get the 45 degree angle. If done carefully, the actual blade edge would not really touch the surface... in my experience... Sometimes a few passes with a blade are easier than sanding.

My other suggestion is to use a piece of double face tape to help hold a piece in place. Scotch makes a thin double face variety that holds up to multiple uses but is not too tacky to stop easy removal of a part. I have many jigs similar to yours Gary, (except only one sided) set at various angles. I use double face tape to hold parts in place for table top saws, disc sanders and knife blades.

gary60s
6th Jan 2015, 07:20 PM
Correct Steve...consistent spacing.

It's cool that you got cutting to work. I just put that in as an escape clause to deny responsibility in case of cutting errors.

NellsChoo
7th Jan 2015, 05:28 PM
Didn't have issues with the part moving, thankfully. It was simply that the resulting bevels were not consistent at all.

ChicagoNW
7th Jan 2015, 07:57 PM
Since the abrasive will wear away the jig no matter the material it is made of.

What about using a Xacto saw from the miter box for the initial cutting. It has a wide blade that can rest on the slope. Then you can finish with an ultra-fine sanding stick that won't affect the jig as much a sanding block would.

ChicagoNW
7th Jan 2015, 08:10 PM
Since the abrasive will wear away the jig no matter the material it is made of.

What about using a Xacto saw from the miter box for the initial cutting. It has a wide blade that can rest on the slope. Then you can finish with an ultra-fine sanding stick that won't affect the jig as much a sanding block would.