May 09, 2009

Mail and Frequently Asked Questions about Model-Building Tools

These are questions I have received from visitors regarding tools used for model-building.

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I was on a control line message board yesterday and someone refereed to your website. I have not had a chance to look at all of it, but what I saw indicated that we share some common traits. Among them are an interest in building your own tools for specific jobs and a lack of sympathy for those who say they don't have the talent to do something.

I am just getting back in to control line building after an absence of thirty-five years. I have already made more tools than I have models. A little over three years ago I decided to try metalworking. Let me state at the start that I am 69 years old and spent my entire working life as a construction project manager/estimator/and superintendent.

I bought an old Atlas lathe that I did not know a thing about and started learning metalworking. I have since added several other metalworking pieces of equipment. Here is a link to some pictures of my second project. It was made entirely from scrap metal using about 100 pictures of the real one. No plans or castings were available. There are about 800 pieces that I had to make.

http://smg.photobucket.com/albums/v421/Keithhs/Corliss/

I am using this as an illustration, not of my superior abilities, but rather what almost anyone can accomplish with a positive attitude and a refusal to say "I don't have the talent." From looking at your website I feel that we share his trait.

Great stuff, Keith. Thanks for sharing!

I am interested in the micro adjustment table that you use with your drill press. I searched the web but could not find it.

X-Y Table Attachment

Hello - I've been enjoying your site for quite some time now, and have incorporated many of your suggestions and techniques into my designs with great success. Thank you so much for dedicating the enormous amounts of time needed for such a site. I've been using a mag board system much like you describe for about a year now, and in general have loved it. I'm having one problem though.

I know that you were able to find a steel plate, however I have used a piece of 22 gauge galvanized steel like you describe in your article. The problem I have encountered is with buckling of the metal — it tends to form "waves" and separate from the wood door core I use for the table top. They're not very high — no more than 3/32 or 1/8", but that's definitely enough to mess things up.

I think this is mainly due to temperature fluctuations in my shop, but since I have no a/c, there's not a lot I can do about it. Any ideas of how I could reduce or eliminate this problem? I previously had the metal glued to the table with 3M Super 77, but have since lifted it off, and it's simply set down on the table top now. The problem doesn't seem any better or worse than when it was glued down. I was thinking of getting another piece of metal, but wasn't sure if this would solve the problem — maybe getting a thicker or thinner gauge?

I’m not real clear on the gauge system other than smaller numbers mean thicker material. What you’re using sounds thin enough that it shouldn’t be able to do what you’re describing. I wouldn’t think it could support it’s own weight.

My personal recommendations have always been doing one of two things: Plan A) Go affordable with thin metal that will conform to whatever it’s on top of or Plan B) buy a sheet of armor and have it milled perfectly flat.

Are you sure the steel doesn’t have a bend that’s making it do what you describe? In your case I think I would try another piece of steel.

I really don’t know what else to suggest. I don’t even know what type of steel I’m using. The guy at the metal shop suggested it because it’s coated and won’t rust and all he said is that it’s steel. There are probably 10,000 different types of the stuff.

Sometimes my shop is climate controlled and sometimes it isn’t. The temperature fluctuates from 75 – 95 degrees and I’ve never noticed the plate having any type of “waves.”

I hope you get the building board sorted out. The height of the waves you’re describing would really bother me. You might just need to buy some lead shot and put it in film containers or baggies or something to weight the steel down while you build.

I love your workbench. Did you build the frame yourself and if so, do you have woodworking plans for it? Also what is MDF from "MDF Bench/Storage Unit".

MDF is Medium Density Fiberboard. It’s the same stuff that discount furniture is made from and then covered in cheap veneer. It is heavy, fairly stable and strong.

Unfortunately I don’t have plans for my bench. I made it up as I was building it. The shelves on the end where I store my wood are 48” long and the shelves on the other end are whatever length was left. I built the bench to be 6” smaller all the way around than the glass top so that I could stand up to the glass comfortable (foot room).

The back of the bench is entirely enclosed. Between the shelves on both ends is a vertical board that spans from front to back and from floor to the top of the bench.

Both ends are open and the shelves opposite the wood storage are also accessible from the front. I mounted one heavy duty power strip at each end.

The wood storage shelves are 1/4” masonite with 1” x 2” cross pieces screwed to the bottom to prevent sagging. These are spaced about every 16”. I also used 1" x 2" screwed to the MDF to support the shelves.

I really like the bench but I made mine slightly too tall. One day when I get motivated I’ll remove everything from the shelves, take the glass top off and run my circular saw around the top edge to make the unit about 2” shorter.

More about MDF

Many times when I come across someone who I regard as a "serious builder" they have these graph-paper-like pads on their building surface. Where do these come from?

I think you’re referring to cutting mats. I bought mine (24” z 36”) at Wal-Mart. You can also get them at most sewing shops. I’ve seen them as large as 36” x 60” but that size was fairly expensive. If you’re talking about gridded paper pads then you can buy them at most office supply stores.

Do you know which is the best type of blade for scroll sawing carbon fiber sheets? I tried the normal Flying Dutchman blades from Mike's Workshop, but they seem to blunt real fast. Any suggestion is highly appreciated !

Warning! Carbon fiber is very dangerous material to work with!

Whenever you are working with carbon fiber you should wear gloves and if you're sawing or sanding it you should wear a filter mask.

Carbon Fiber is a very hard material and is going to dull your blades. The best thing you can do is use a saw that has a water trough to lubricate and cool the blade. The next best thing is to put oil on the cut line for the same purpose.

No matter what you do your blade is going to dull quickly. I don’t know what you can do about it other than what I mentioned. I don't know what specific blade will do the best job.

Some time later I received an e-mail from Boris who suggested trying a diamond scroll saw blade. I have never used these blades and can't recommend them one way or the other, but I would certainly give them a try.

Scroll It Home Page — Click the Diamond Scroll Saw Blades link.
CyberRockHound.com - Click the Lapidary Saw Blades link.

I would like to build some of the magnets at these prices but was wondering where you found the plates for the magnets or how and out of what you cut them?

The steel plates come with the magnets if you buy them from The Magnet Source.

Can the 5" blades from Mike's Workshop be used for 16" and 22" (throat depth) scroll saws?

Throat depth on a scroll saw is entirely unrelated to blade length. 5” is the standard scroll saw blade length so it should fit most saws, but you’ll have to consult the manual for the saw to be sure.

I have many pieces of 1/8" plywood where I need to saw a rectangular slot 1/8" x 6" in the middle of each piece. How do I go about cutting these slots such that they are straight and the width is accurate? I have to ensure that the slots are straight and accurate because I have to slide a piece of 1/8" ply into the slot later.

How to Make Perfectly Straight Cuts Using a Scroll Saw

Could you send me the item number's for the scroll saw blades you get from mike's workshop? Are they the Superior Puzzle blade (FD-SP?) or fine reverse tooth blade (FD-SR no. 2/0)?

It is the model number FD-SP. The blade is actually called the Superior Puzzle blade. You can find it almost at the end of this page:

http://www.mikesworkshop.com/blades.htm

One thing I did not mention on the Power Tools page is that this blade does not cut straight lines well. Be sure to tension the blade properly. Most folks don't apply enough tension which makes the blade wander more and break sooner.

I like the Puzzle blade because it gives the cleanest cut of any blade I've used on balsa. But it takes some practice to make it go where you want it.

I am curious about your Dremel router setup. I do not own the router accessory yet, but I am curious to know how you attached it to the work surface. Can you perhaps send a picture of the underside of the table? It will be of great use to me in rough sanding and general routing.

I've received a few e-mails asking for more details about the router table. The problem is that I bought the 1/2" MDF when I was stationed in Germany a few years ago and I haven't found any locally. I'd like to make another table and make some improvements. While I'm at it I can do a more thorough how-to.

In any case, what I plan to do until I find the right material is go ahead and take some more photos of what I've got and I'll separate it out from the Dremel page and make it a dedicated How-To in the Tools You Can Make section of the site.

Basically what I did was buy the router base and take the base off the housing. I used the two screws that held the base to the housing to bolt the housing to the table. Once you have the router accessory you'll see what I mean.

The only tricky part is finding where to actually put the hole in the table because there's not a good place on the housing to measure from. I drilled the hole undersize at first and then mounted the tool. I eyeballed a circle template over the center of the moto tool and then used a real router to enlarge the hole. It's not perfect, but it's close enough.

I found your site some time ago and referenced it quite a bit before buying a compressor. Now I am trying to figure out which spray gun to get — probably will end up with an air brush and detail gun.

On the detail gun side, I am not quite sure whether to go with the HVLP type or the Badger 400. I saw a neat little Ingersol Rand model 200G HVLP at Home Depot once, but can not find any information about that model. I do not even think it was in their regular listing as I have not seen one in any other Depot stores. Am I correct in thinking that I want a sprayer that has a 1mm or less opening?

Otherwise, the biggest problem seems to be what paint to use to get a nice finish that is fuel proof to 15% nitro. I do not like the fumes from the nasty stuff like dope. Others have said latex works well with some sort of clear coat. I looked at all of the guns before buying the compressor, so I did get a hefty model with lots of CFM.

I really like my Badger 400. The medium tip that it comes with has worked fine for me. I haven’t had need or desire to buy the other tips offered for it. I can’t tell you anything about HVLP because I haven’t ever used this type system.

As far as paints go, I prefer epoxies. They go on nicely and are very fuel-proof. However, they are no less hazardous than dope — probably more so. You should spray outdoor and wear a charcoal mask.

Unfortunately, the paints I used for years are no longer manufactured – HobbyPoxy and K & B SuperPoxy. I use Klass Kote Epoxy Paint and am very happy with it. Klass Kote is compatible with HobbyPoxy and SuperPoxy.

Nelson Hobby sells a water-base epoxy that a lot of guys are using. I haven’t used this paint but I’ve heard good things about it.

Can you give some advice on a good way to strip balsa? Mine always comes out bowed (using master airscrew stripper). Is there a better stripper available?

I run in to the same problem. For thinner pieces, I use a straightedge and hobby knife. For thicker pieces, such as spars, I use my Microlux table saw. There is not a lot you can do about it because you can not tell in advance if the wood is going to bow or not.

One thing you can do if it is critical is strip the wood slightly over-size. Then if it bows, you can trim off the excess and hopefully remove most of the bow. My experience has been that bowing is not really much of a problem because by the time the structure is complete, the bow gets removed by the rest of the structure and it is stiff enough that it will not come back.

I received my magnets today. I wanted to know if you glued any of your metal plates to the magnets that you have, and if you did what type of adhesive did you use?

I glued plates to some, but not all, of the magnets. I have used both CA and Epoxy. Unfortunately, the plates break off easily due to no glue sticking to chrome very well. It works better if you sand the inside of the plate (the side with the sharper edges) with some coarse grit sandpaper first.

Clean off the sanding crud, apply the glue and use a nut and bolt to hold it together while the glue dries. Do not over-tighten the bolts or the magnets will crack. The magnets (ceramic) are very fragile, so also do not drop them.

I just purchased a used Ajusto-Jig. However the directions and steel rods are missing. Came upon your site and it is helpful. I see you use the jig and am wondering if you know the size of the rods? Also, do you have the directions?

The rods are 5/32” music wire. They are held in place by rubber bands over the red plastic jig pieces.

The holes in the ribs have to be drilled such that when you stack the ribs they align properly. Therefore, if you want to build in washout, then when the holes are aligned, you should see the tip ribs at an incidence setting lower than the root ribs.

The holes in the ribs are drilled 2” apart. Use a 5/32" bit. Be sure to actually lay one of the red jig pieces over the rib before deciding where to drill the holes so that the jigs won’t interfere with wing construction.

If you are building a D-tube wing, you can build the complete panel in the jig. However, if you are building a fully sheeted wing, then you can only sheet the side of the wing that is up in the jig. The jig itself would interfere with putting sheeting on the other side. Therefore, the wing has to be removed from the jig to sheet the other side. Of course, you will have to put the wing on a flat board to do this, because a wing that is sheeted on one side only is very flexible and can have a warp easily built-in.

As far as the fuselage jig goes, I can’t help you. I could never get it to work properly and didn’t feel it was well designed.

Instructions for Ajusto-Jig (1.6 Mb zipped)

What a great building board. I have seen the Great Planes board in Tower Hobbies. However, the price seems to be a little steep. I also understand that the quality of the product is inferior. How did you go about making the board?

I have the following questions:

How much did the magnets cost?
How did you make the magnet clamps? It looks like some of them have metal plates on the outside.
What type of wood did you use to make the squares in the fuselage example? Do you have templates for making these?
Is the board you are using the Great Planes board?
The clamps look awesome. What hardware do you use?

You have a great website with a wealth of information. A how-to article on making your building board would be a great addition.

I have been asked several times for a how-to on the building board system I use. Here it is:

Magnet Building Board System

Found your wonderful web site address in September 2003 issue of RCM. Do you have any recommendations on what scroll saw to get that would be better and the reasons?

As a rule of thumb, the deeper the throat of a scroll saw, the more the saw vibrates. Therefore a larger saw is not necessarily better.

I suggest a 14" or 15" model because it can handle just about any reasonable thickness of wood we use and can handle 99% of all the cutting we would do with a scroll saw.

Things to look for are variable speed, built-in sawdust blower, tilt table (necessity), built-in light and a vacuum attachment. Another feature that you should look for is a saw that allows the blade to be turned sideways. This will allow the saw to cut unlimited lengths regardless of the throat depth. However, when the blade is sideways the table can not be tilted.

I can not recommend any particular model saw, but you might go to a forum for a craft that makes more intensive use of scroll saws. A forum I recommend is Small Stuff Miniature Digest.

Talk to Mike at Mike's Workshop for blades for your saw. I had a heck of a time finding quality scroll saw blades before I came across Mike's. He carries very high quality blades.

The blade I use the most is the 31 TPI (tooth per inch) Superior Puzzle blade. They break easily, but a gross (144) of blades costs only $22.50.

Where can I get an Ajusto-Jig?

My only suggestion is to try searching on E-Bay.

After reading your review of the Microlux table saw I ordered one up. It arrived today and my initial impression is favorable. It only took some minor tweaking to square up the blade and micro adjustable fence. Thanks for bringing this quality piece of machinery to my attention.

It seems there is not a lot of choices in blades for this saw. I have looked around online and around town without any results. Besides of course MicroMark. I have found a couple of 3-3/8 blades intended for the cordless saws, however they all have 15 mm arbors.

I will mostly be cutting balsa and plywood for R/C aircraft construction, and while the provided 80 tooth blade cuts balsa cleanly, it tends to wander a bit on spruce and thick plywood. Have you found this to be the case? This blade also has a significant whine, which I have always equated with internal stress, at least with larger blades.

The carbide blade offering is much thicker, but at the price of a much thicker kerf. Have you used this blade? Have you found another source of blades appropriate for this saw?

You mentioned not being able to mount an auxiliary fence for ripping stock. Have you tried using one of those T sander extrusions with the fence provided with the saw? You would have to trim down one side of the T, and drill and tap holes in the top of the fence. I have seen those sanders in two foot lengths and they may be available much longer. That should give you the needed length to your fence.

Also, could the bowing you encountered be the result of stress in the stock? I have dealt with this with larger stock while building various projects around the house.

Before I answer these question I need to make it clear that the Microlux table saw is the only table saw I have ever owned or operated. In other words I do not know a lot about table saws. However, I have had very good success overall with this saw which is about as good of an endorsement as I can give it. It is easy to use and does a great job.

I purchased all the blades I use for my Microlux saw from MicroMark at the same time that I purchased the saw. I have not looked for blades through other sources and am not aware of any where else they can be purchased. However, the accessory blades sold by MicroMark are made by Globus and require an arbor adapter. The saw has a 10 mm arbor and the accessory blades require a 1/2" arbor. If you search for this brand you may find other outlets for the blades. The adapter can be purchased from MicroMark for about $5.00.

The adapter appears to be something that could be machined easily. It is basically the same as the washer that holds the blade in place with a thin lip to fill the gap between the blade and the arbor. If you can make an adapter and find blades that are close to the right size I think you would be in business.

These are the blades I own in addition to the stock blade. They are listed in order of how much use they get with the first blade being used about 99% of the time.

3" x .045" x 168 tooth
3" x .032" x 168 t
3" x .025" x 225 t
3" x .020" x 225 t

I have had no problems with significant splintering using any of these blades. I do not recall ever using the stock blade because it just did not look like it would cut cleanly. The above listed blades cut so cleanly that little or no sanding is required.

I now have the Carbide tooth blade sold by MicroMark. Wow! What a wonderful blade! It can easily cut through 3/4" rock maple motor mount stock which really surprised me. It does have a fairly large kerf compared to the other blades, but it is a small price to pay for being able to cut thicker wood with the saw. This blade will splinter plywood when the blade exits during a cross-cut. However, if the piece is moved slowly enough, it can be kept to a minimum.

I have not noticed any blade whining. I keep the saw on it is lowest speed for the most part. What I have noticed is the thinnest blades (.025" and .020") will begin a nerve shattering oscillation if the stock is not push through perfectly straight and the saw is running at a high speed. Once it starts the only way to stop it is to shut off the saw.

When I say there is a problem with bowing, what I mean is that if I feed a 3" wide sheet through and cut off a 1/4" stick, the remainder of the 3" wide sheet bows. I know this for a fact because I have trued the edge of these sheets several times and it continues to be a problem, so I doubt it is from internal stress. If the stick bowed, but the edge of the sheet remained straight then I would assume internal stress. I think a longer fence will correct the problem.

What I have done is taken a long piece of extrusion (aluminum molding) and clamp it to the saw using needle nose spring clamps. I can get four clamps on it, but it is not super secure so I have to be careful not to bump it. Once I get it set up I cut a bunch of sticks so I will not have to do it again any time soon.

Your suggestion of bolting a piece of extrusion to the stock fence sounds excellent and I think it may resolve the problem. Thanks for that tip! After I get something set up I will post the results on the Power Tools page.

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