Mirrored parts

Folk's I'm looking to make my firewalls identical to each other so that when I make up my crutch that the fire walls sit flat on the building surface with out that "rocking" motion..
What I have been doing is tack glueing the fire walls together, then cutting them out.. Also at this time cutting the motor mount notches out. I'm using an OLD dremel saw (35yrs) to make these cuts.. Also sometimes the m/m notches aren't quite the same..

Any help sure will be appreciated...

Gil

Gil, the tac gluing of the firewalls together is a good thing, but if you do not get the saw EXACTLY perpendicular to the surfaces while cutting them out of the sheet, they will not be square with each other in any direction. The best thing that you could do is get a small "three wheel" bandsaw. They can be obtained from a lot of different sources such as Home Depot, Harbor Freight, Lowes, and a host of others. They range in price, but all are very similar in setup and performance as far as model work is concerned. If you can afford one, that is the better way to go and they are compact enough that you can set them up on just about any surface. Of course you should get a spare blade so you will have a spare when one breaks, which is bound to occur just when you need it most and at a time when all stores are closed. (Murphy's Law #17885). I use a "metal cutting" blade for all my model wood cutting work. Ply as wellas balsa as the metal cutting blades have more teeth per inch and give a smoother cut. That relates to less sanding.
Bigiron

Marvin is right-on, if I was starting from scratch I would buy a band saw first, hardly ever use my scroll saw anymore.

Gil,
As BigIron points out, having the blade perpendicular to the table is vital. I assume what you are doing is splitting the firewall vertically, so that both sides, including the motor crutch slots, are cut simultaneously). If you have a square, try to make sure your Dremel (the jig saw?) blade is perpendicular to the table. It is easy to get misaligned, because a lot of us have a tendency to grab the Jigsaw arm when we pick it up, and this certainly can alter the angle (also the table holddown -a wingnut is no great design either!)

OK, I'll argue the other way (I'm a Scrollsaw type - My "moniker" on several other forums is "jigsawyer").

It's easy to square the table to the blade. Use a small piece of scrap 1" pine (or Fir or other softwood). Cut into the piece about 1". Then turn the saw off; turn the wood over and see if the blade will slide into the cut. Adjust the table if necessary and try again.

When the blade DOES slide in, then cut in about 2" and cut a 1"-1½" square. If the square slides in-and-out from both directions, the table really IS square, and you can trust the cut.

One other (profound) advantage of a scrollsaw is that it's a "bandaid" tool. If you really mess up, you can fix the wound with a bandaid. That ain't true with a bandsaw!

You might also consider getting a better scrollsaw. The Dremel Moto-Shop has its uses, but it is NOT a great scrollsaw (or anything else). You can get a Delta 40-540 for under $100 (new) from www.toolking.com or find a used one for $75 or so. It must be bolted to a solid tabletop to control vibration. A "real" scrollsaw cuts much better/faster than the Dremel.

Just my opinion . . .

Hi!

The scroll saw that Ralph reccomends in the above post appears to be the same unit that is also built (Or sold.) By Riobi and available at Home Depot under that brand name.

I upgraded from the little Dremel scrool saw several years ago and never looked back. The Ryobi saw is heavy and built like a brick. When you adjust it to an angular setting it will stay where you put it. Just what you need once you get fussy about details. I like to move mine around to different locations in the shop as needed and find that the settings on mine never change unless I fiddle with them. It also has a hose adaptor whitch, with a little fiddeling and a right angle adaptor, will allow connecting to a shop vac. Put all your tools on one bench, rig up a shop vac under the bench and you is STYLIN!

If you talk to a Ryobe distributor you can frequently get a good deal on a 'remanufactured' unit. Not only will you save a few bucks but you'll get a saw that went through the setup process twice, assuring a primo tool. Thats what I did. I also bought a couple of Ryobi 'Dremels" at the same time. One with the flex extension, one without. I was used to burning out a Dremel Tool every couple of years. The Ryobi's just go on and on. In fact, one of them is still NIB.

If you look around, you can pick up a small machinists square for a few dollars. It's a simple matter to place it on the platten and then align the platten 90 degrees to the saw blade. Get the tool, keep it next to the saw, use it!

I've gotten along with just the scroll saw for a long time but intend to add a band saw to my shop shortly. The Ryobi is about $100.00 and the Sears job about the same.

If I only had room or bucks for one saw, I'd go with the Band Saw since they'll cut alnost anything with the correct blade. Then, I'd spend the saved $100.00 on the little Ryobi Drill press. It'd be just right for my jobs.

By the way... One spare blade?! I'd buy at leaste five! When it rains it pours, LOL!!!

Later

Bigs

PS:
One little trick for doing the firewalls is to tack the pcs. together and when you get to the MM holes, cut them fractionaly smaller than measured. Then, hand fit them by trimming slightly with a sanding stick applied to One edge only. I can usually achieve a snap-together fit that way and can therefore check my alignments, tank installation and so forth before gluing anything together.

Try it. You might like it!

I use a 16 in. Sears jigsaw. I trim a piece of hacksaw blade(wide) to fit in the blade holders, grinding it with a Dremel tool. The hacksaw blade cuts almost as fast as a little bandsaw, but a decent jigsaw is much more stable cutting than the bandsaw ever was.

Square cuts are easy. A good jigsaw has a table that tilts both sides of center to 45 deg. Just trim it as mentioned here to get it set square.

Hi Gil. Until you do get a new scroll saw or better yet, a bgand saw. try this. Using a steel stragiht edge, run a #11 blade over the lines you are going to cut. A small cut will help the blade follow the line. I did this on my old Dremel scroll saw and even though it walked all over the table, the blade tended to stay in the cuts. I have a band saw and a new heavy duty Dremel scroll saw. I prefer the bandsaw nine out of ten times. It just makes life so much easier and building just goes so smoothly. Hey, when's your birthday? My wife got me mine. Actually she gave me a gift card for Home Depot. It's right next to Lowes. Big hint to wife.

Hi guys

I would like to add one thing to this discussion.

When I went shopping for a small bandsaw several years ago, all the power tool companies that I spoke to recommended against 3-wheel band saws. In modelling sizes, you might get a 3-wheel machine with, say, 6" wheels while a 2-wheel machine with 9" wheels is a little taller but does not take up more bench space. The power tool people were unanimous in their advice that, in the sizes that we are likely to use, the 3-wheel machines break blades more frequently.

Geoff,
Within a year after I got a 3-wheel 10" Delta, they dropped the design and replaced it with a 8" two-wheel. Fortunately, both use the same size blade.
Once you get the tension and tracking adjusted correctly, the 3-wheels work well, although they do tend to go through blades.
I understand that the most common problem with band saws is that folks tend to set the blade tension too low.
I like the smooth operation of a band saw as opposed to my scroll saw tending to rattle the wood around. I probably haven't learned to use the proper blade size and shape. One advantage of the scroll saw though, you can cut inside firewalls, etc. by just drilling a hole and mounting the blade through the hole.

George