H

HelioJoe

Well Known Member
Yesterday I was preparing to cut the canopy on a 9A when an old friend "IA" stopped by to visit and asked what I was going to cut the canopy with. Like everyone else, the die grinder and a cutoff disc. He said he had something better and returned in the morning with an orthopedic "CAST CUTTER". That is correct, doctors cut the cast off a broken bone etc.
The old "IA" has been cutting plexi/Lexan for 40 years with it with no problem.

I tried it and was amazed......no dust at all....no need for a mask.....no hot chips....no melting plastic......thin circular blade appears to be rotating but it's not, it's oscillating.....very fine control....does not want to climb if going in the wrong direction........ you can put it on your hand and it will not cut you.....and it's quiet, no compressor or high speed angle grinder noise.

First cut was to "score" a groove as a guide, second pass was right through like butter.
Find your doctor friend and see if he will let go of one. You'll never give it up.

Works good and lasts a long time......Heliojoe.
 
Fantastic for ya

Joe

Where were you and your IA when I needed ya........don't you just love folks that bring great ideas and inovation to our hobby........

Frank @ 1L8 ... RV7A ... last 993 details
 
Innovative Ideas

fstringham7a said:
Joe

Where were you and your IA when I needed ya........don't you just love folks that bring great ideas and inovation to our hobby........

Frank @ 1L8 ... RV7A ... last 993 details
Click to expand...

Hi Frank.....I agree with the ideas...sometimes we just dont see the forest for the trees. About a week ago I was mounting the vertical fin for drilling etc and could not quite get the fin perfectly vertical "0" degrees. Built a lot of Cubs and Super Cubs with the flying wires attached to the Stab and vert fin. All of a sudden I had a storm in my brain.!!!

Attached safety wire from the top of the vertical fin to the horizontal stab with a turnbuckle on either side, in between both. Easy as pie....tightened and loosened the turnbuckles till the fin was dead on then, clamped, drilled and tightened all the bolts. Just another idea that works.....Joe.
 
circular blade

HelioJoe said:
Yesterday I was preparing to cut the canopy on a 9A when an old friend "IA" stopped by to visit and asked what I was going to cut the canopy with. Like everyone else, the die grinder and a cutoff disc. He said he had something better and returned in the morning with an orthopedic "CAST CUTTER". That is correct, doctors cut the cast off a broken bone etc.
The old "IA" has been cutting plexi/Lexan for 40 years with it with no problem.

I tried it and was amazed......no dust at all....no need for a mask.....no hot chips....no melting plastic......thin circular blade appears to be rotating but it's not, it's oscillating.....very fine control....does not want to climb if going in the wrong direction........ you can put it on your hand and it will not cut you.....and it's quiet, no compressor or high speed angle grinder noise.

First cut was to "score" a groove as a guide, second pass was right through like butter.
Find your doctor friend and see if he will let go of one. You'll never give it up.

Works good and lasts a long time......Heliojoe.
Click to expand...


Hi Joe! I was wondering, if the blade is circular, can it be rotated to move dull teeth out of the way and new teeth in?

Thanks
 
The most common are by the Stryker company (and are called Stryker saws). In addition to the cast saw, they also make autopsy saws that are essentially identical. They come with different blades - some are almost T-shaped, with the broad part of the T being a hemi-circle, as well as fully circular blades. You can change the blades out. You can also rotate the saw to use different parts, but it's really meant to be gripped a certain way and it will feel VERY uncomfortable if you rotate it too much.

Most of my experience with these is with skulls and spinal columns, but they work VERY well and don't really get dull. You do need to make sure the nut holding the blade on is tight, because it's ugly when one comes off while the saw is in use. :)

Off topic: Stryker autopsy saws have a huge label on them saying "NOT FOR USE IN THE PRESENCE OF FLAMMABLE ANESTHETIC AGENTS", which I've always found hilarious. I once got the chance to ask a company rep about it, who didn't find it as funny as I did. :)
 
This sounds like a great idea! Perfect timing too, as I am about two to three weeks from starting the canopy trimming!

Carl!! Are you listening...;) :D Bring one home for me!
 
cast cutter

Robert M said:
Hi Joe! I was wondering, if the blade is circular, can it be rotated to move dull teeth out of the way and new teeth in?

Thanks
Click to expand...

Hi Robert........I really don't think it would be necessary to rotate the blade and yes it is circular. Maybe just turn the whole thing?? Blade is very sharp, old "IA" been using it for a long time and has never changed blades.
KHELMAR has a great history write up on the uses....Joe
 
A question

After a lot of years riding motorcycles and skydiving I have had several personal experiences with the cast saws but fortunately none yet with the autopsy ones. :D The general wisdom regarding plexiglass cutters is to not use any sort of reciprocating tools due to the increased risk of cracking the plastic. I understand that these saws are nothing like a Sawz-All but am curious if there might be a higher risk of cracking the canopy with this method versus using an angle grinder or Dremel tool with a spinning cut-off blade since it seems to me that the cast saw is really a high frequency reciprocating saw.

Do these cast saws oscillate at a high enough frequency and low enough amplitude (the blade barely moves) that they don't increase the risk of cracking the plexi?

I'm not saying it isn't a good idea; just wondering about the ramifications of the oscillating/reciprocating action of this tool. I would have paid good money to not have all that plexi grit flying all over me and everything in the shop so this sounds like it might be a really god deal!
 
A Cheaper Solution

I just made my BIG CUT on my RV-9 slider and used my Dremel and some 1.5" cutting discs made for cutting plastic. Home Depot and Lowes have them in packages of 5 for around $10.

080502f.JPG


I made all my cuts and there was no dust but lots of larger specks like grains of sand that easily wipe off. I used only one disc and as you can see from the photo, it barely looks used.

http://www.flightinnovations.com/canopy.html#The_BIG_CUT
 
Oscillating saw

rvtach said:
After a lot of years riding motorcycles and skydiving I have had several personal experiences with the cast saws but fortunately none yet with the autopsy ones. :D The general wisdom regarding plexiglass cutters is to not use any sort of reciprocating tools due to the increased risk of cracking the plastic. I understand that these saws are nothing like a Sawz-All but am curious if there might be a higher risk of cracking the canopy with this method versus using an angle grinder or Dremel tool with a spinning cut-off blade since it seems to me that the cast saw is really a high frequency reciprocating saw.

Do these cast saws oscillate at a high enough frequency and low enough amplitude (the blade barely moves) that they don't increase the risk of cracking the plexi?

I'm not saying it isn't a good idea; just wondering about the ramifications of the oscillating/reciprocating action of this tool. I would have paid good money to not have all that plexi grit flying all over me and everything in the shop so this sounds like it might be a really god deal!
Click to expand...

HI Jim........Not an expert but what I observed.......the circular blade is moving so fast that you think it is rotating. When you turn the switch "off" just before it stops you will see the oscillation. Before I actually went to the real canopy for the first cut, I tried it other pieces, fast, slow, hard, light touch and actually twisting it as to make a curve. It did all this with no problems. There was not a chip or questionable spot anywhere and the cut was smooth faced.....just my observation....Joe.
 
I have cut and trimmed five canopies and have acquired a bit of a knack for getting the job done quickly. It takes me about two hours start to finish by using an angle grinder with a thin abrasive disc. My angle grinder is a Metabo but even a harbor frieght would work fine. Using an air powered die grinder or cutoff wheel will just give you headaches, since they never have enough torque to cut the canopy quickly.
 
I've used quite a few of these doing ortho work - the blade barely rotates back and forth and with high frequency. You can safely rest the powered blade on your palm, though I wouldn't over a bone (like a knuckle). Chad, I can try and swipe one, but the "study" population of one example done this way isn't too reassuring compared to the many who have done with grinding wheels, etc. Experimental can be fun, except with a $1000 canopy :eek:.
 
Some blades are circular and can usually be rotated, but only 180 degrees; so you have two useful arcs of teeth. They do dull with use. Other blades have only one segment of arc and thus can't be rotated. Even though I use these all the time and can get one easily I never thought of using it on the canopy. Bill
 
canopy cutter

Would you post the manufacturers information from the data plate on the cast cutter. Maybe we can check it out, and buy one for our EAA chapter??
 
INFO

Flyer68 said:
Would you post the manufacturers information from the data plate on the cast cutter. Maybe we can check it out, and buy one for our EAA chapter??
Click to expand...

Hi.....already returned it to the IA, but could go back and get the info.
I do remember the data plate said "Stryker Cast Cutter"...hope that helps....Joe.
 
Another type of cutter.

Hey all,
Just thought I'd add my 2 cents worth. I have been using a Fein detail sander/cutter for the same purposes. It not only will cut but is the best detail sander on the market. It even offers optional blades that will cut tile. Check out Fein Tools.
Woodman.
 
Yet another option

I've just got hold of the Bosch PMF 180 E and tried it out on a corner scrap from a freind's RV-8 canopy. I think that is possibly like the Fein cutter above, but Bosch tools are widely available in Europe.

Anyway, it worked perfectly with minimum dust and debris. I then put a scrap of canopy in the freezer for an hour and had another go just to make sure before diving in on my canopy. Again no problems. I even managed to cut a bit of a curve, though the flat cutter blade rather constrains that.
It cost me ?60 (roughly $120), so rather cheaper than the Stryker saw.

Another good point is you can put your hand on the moving blade and it won't leave a mark, but it's probably best not to try.
 
rocketbob said:
I have cut and trimmed five canopies and have acquired a bit of a knack for getting the job done quickly. It takes me about two hours start to finish by using an angle grinder with a thin abrasive disc. My angle grinder is a Metabo but even a harbor frieght would work fine. Using an air powered die grinder or cutoff wheel will just give you headaches, since they never have enough torque to cut the canopy quickly.
Click to expand...

Hi Bob,
Are you referring to the 4" right angle grinder Metabo makes? Those are really nice tools.
Charlie Kuss
 
FEIN MULTIMASTER

This tool has been all over Dish Satelite paid programs recently. It looks like it might be a similar tool.

multimasterbig.jpg


They need to eliminate at least 2 of those $97 payments though!
 
We have a company that sells a similar tool in australia, the're called WURTH and the cutter is designed for steel and works on the same principle of osilations rather than spinning, you may find them in the US ,cheers Mat
 
True to form, Harbor Freight recently introduced a version of this tool for dirt cheap ($60, on sale for $40): item 65700. Haven't tried it, just thought I'd mention it.
 
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