Erector set part number 'NU' parachute men punch and die

BGHansen

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I’m a long time member of the A. C. Gilbert Heritage Society which is primarily a club of Erector set collectors. The ACGHS (www.ACGHS.org) hosts an annual National meeting which this year will be in Huntsville, Alabama. The club is a fairly tight-knit group and most members are known for something. I’m known as a former editor of the club newsletter, set layout diagram book author and reproducer of parts. One part I make is part number ‘NU’ parachute jumpers.

Lifesavers hosted an exhibit at the 1939 World’s Fair in New York; the iconic parachute jump ride. By the way, the structure was recently restored and is standing on Coney Island. Fair goers were pulled up the jump tower via a cable and floated down to the ground riding a parachute. A. C. Gilbert took advantage of the fervor over the popular ride and in 1940 came out with an Erector set model of the Lifesaver parachute jump ride.

Larger Erector sets from 1940 – 1962 came with parts to build the ride model and included 4 of the part number ‘NU’ parachute jumpers. The part varied through those years with either white or red silk parachutes and bamboo or red plastic struts. I usually make up 20 – 40 sets of the parachuters a year and sell everything I make. I’m always looking for ways to improve my throughput and decided to FINALLY make a punch and die to cut out the parachute guys.

The men are two-sided, same image on both sides, glued to a piece of chipboard. I usually glue the images to the chipboard and cut them out by hand while watching TV. I’d hate to think of the number of hours spent doing this when I could have been out in my shop! I’ve made over 500 sets of the NU’s over the years or hand cut out 2000+ of those little guys . . .

OK, on to the die. The parachute guy blank is about .65” x 1.7”. My Roper Whitney #218 punch press uses 1 ¼”, 2 1/8” or 2 ¾” dies. I went with the 2 ¾” die for this project. The die was made from a piece of 3” OD, 2” ID tubing with an O-2 3/8” thick insert. I didn’t have any O-2 in that diameter so went the route shown here because of materials available.

Started by turning the piece of tubing to diameter, cut off in the band saw, then faced & bored on the lathe. The die base then went to the mill. My O-2 stock on hand is just over 2” wide and just over 3/8” thick, so I notched the die base for the O-2 slab to set in place. Once the base was machined, the O-2 slab was clamped in place and doweled on either end for locating. Then (4) 8-32 holes were drilled and tapped; clearance holes through the O-2, tapped holes into the die base.

It dawned on me while contemplating the hole locations that my mill has a DRO with a PCD function. Don’t know what the acronym stands for, but it’s holes on a circle/arc. A quick protractor check showed 15 deg. angled holes above and below the dowels would work great. Set the mill at the center of the die base, entered the circle diameter, started at 0 deg., ended at 360 deg. and chose 21 holes. The DRO considers 0 deg. and 360 deg. as two different points, so I always add one to the number of holes on a circle and start at 0 and end at 360. Otherwise I’d have to calculate the last hole angle which in this case would have been 345 deg., but frankly I find it easier to just add one to the number of holes and always start/end at 0/360.

Once the O-2 was fastened into place the profile of the parachute guys was drilled/milled into the tool steel. Nothing earth-shattering here, fortunately the widths were all standard end mill sizes. I crept up to the final pass with progressively larger end mills and as expected went over-sized on the slot widths by about 0.003 – 0.005”.

Next, the punch. The R-W #218 takes either ½” or 1” diameter punch shanks. I made the punch body from a piece of 1 ¾” diameter CRS. Turned one end down to 1.000” in my Grizzly G0709, then on to my Clausing #5418 with a 5-C collet chuck for facing.

Plan was to attach a piece of O-2 tool steel to the CRS punch body. I Dykem’d up a piece of O-2 and clamped it to the die, then scribed the profile on the punch piece of O-2. This piece was then clamped to the punch body which was held in my mill with a 1” 5-C collet and a square collet block.

I drilled and tapped a hole through the O-2 into the punch body for securing. Once screwed in place, rotational tram was verified with a wiggler. It was easy to leave the clamping screw a little loose to rotate the O-2 until it was square to the table. Then two dowel pins were added for locating. Next step was milling away the extra O-2 on top of the punch body. Once it was close (within 0.005” of final size), the O-2 was removed from the mill/punch body.

Oh baby, do I like having an Oliver die filer for fine detail work! It took about an hour of filing, but finally got there. Kept Dykeming and scribing the overlap between the punch O-2 and the die O-2. Had a big grin on my face when the punch slipped through the die with about 0.005” of room to spare!

Back to the mill with the punch body to cut in some anti-rotation notches. Then screwed the punch O-2 piece to the punch body and set everything in the R-W #218. I made a quick and dirty fence from a piece of sheet metal held in place on the press table with some rare earth magnets. I’ll likely do a POTD to make something a little more solid in the future, but the quick and dirty worked OK. I haven't hardened and tempered the O-2 yet; after all it should last a very long time as it's only cutting paper. Maybe next time I fire up the oxyacetylene torch they'll get the finishing touches . . .

This is where I bang my head against the wall for spending many, many hours for years cutting those little guys out by hand. I’d cut out around 36 guys in about an hour and end up with calloused hands. Now I do one about every 5 seconds. Sure is nice to be able to combine two hobbies, gonna have plenty of parachutes available at the Huntsville show!

Bruce

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Bruce,

Wow!
Giving the above (...and your other detailed write-ups of punch and die design) a single little "like" seems woefully inadequate.

I am blown away at your:
-attention to detail
-willingness to share
-effort to produce such high-quality photos and write-ups
-passion for your hobby

I have never even used a punch and die machine any bigger than a hand-held pliers type. However, I recently acquired a heavy Peck, Stow and Wilcox 676A-1 punch frame and am looking forward to exploring the possibilities.

I find your posts inspiring and I wanted you to know that they are genuinely appreciated.

Thanks!
-brino
 
Bruce,

I'm going to have to hit you up for some of them if you have any left from the show.:D

I'll buy them un-assembled if you include some tape with them!

I've actually made some myself, many years back, not as nice as Bruce's. He's is not kidding, there is a lot of work in making them.

Nice work there, Bruce!
 
Bruce,

I'm going to have to hit you up for some of them if you have any left from the show.:D

I'll buy them un-assembled if you include some tape with them!

I've actually made some myself, many years back, not as nice as Bruce's. He's is not kidding, there is a lot of work in making them.

Nice work there, Bruce!
Hi Ken,

Thanks for the kind comments. Yeah, the men are just one of the steps. The disk at their waist is made from thinner chipboard. I knock out the disks with a hollow core punch, but will be switching over to the R-W press with a 5/8" punch/die. Just easier work than banging on the hollow core with a 2 lb. ball peen. Something about recovering from my third hernia surgery in the past two years (latest surgery was 6/1) making me rethink how I do things . . . Then punch a 1/16" x .375" slot in the middle of the waist disk. Soak the disks in polyurethane and lay them out on some wax paper for drying. The urethane makes the chipboard really stiff like the original disks. After the disks are slipped over the legs and glued in place the holes for the string attaching the chutes to the men are drilled through their shoulders.

The chute material is cut on a self-healing mat with a rotary scissors (5" squares). The top washers are 5/8" OD pieces of black chipboard with a 3/16" center hole. The chute gets a hole cut in the material, then a 3/16" brass eyelet fed through a pair of the black washers on either side of the material, then crimped in place.

I make the struts by splitting bamboo skewers with an X-acto knife. The plastic ones are made from clear red acrylic rods 1/16" in diameter. Cut small lengths of string that gets glued to the rods, then wrapped with a piece of 1/4" masking tape. Then wipe a coat of tacky glue on the outside of the tape to keep it from unrolling.

Set the chutes out on our pool table and glue the struts in the corners. Then wrap the corners with 1/4" masking tape and a coat of tacky glue. Slip the string through the hole in the guy's shoulders and glue in place. Lots of tedious work, but most of it's done sitting on my butt, so not too strenuous. One of those mixed bag parts; just tedious enough work that guys in the club don't fiddle with making them when for $20 they get a complete set of 4.

By the way, my mother-in-law gave me a stocking stuffer a few Christmas' ago that was wonderful. She gave me a tube of a UV-activated gel glue which works great. It squeezes out of a tube in gel form and stays liquid until it's hit with UV light. Instant set up at that point - like superglue that goes hard only after it's hit with the light. So now I squeeze out a dob of the glue, dip the struts in it, set them in place on either the string or chute material and shine the LED on them - instantly tacked in place. I used to dip in tacky glue and have to wait 10 minutes for it to set up. Makes things go a little quicker.

Bruce

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Bruce,

Wow!
Giving the above (...and your other detailed write-ups of punch and die design) a single little "like" seems woefully inadequate.

I am blown away at your:
-attention to detail
-willingness to share
-effort to produce such high-quality photos and write-ups
-passion for your hobby

I have never even used a punch and die machine any bigger than a hand-held pliers type. However, I recently acquired a heavy Peck, Stow and Wilcox 676A-1 punch frame and am looking forward to exploring the possibilities.

I find your posts inspiring and I wanted you to know that they are genuinely appreciated.

Thanks!
-brino
Hi Brino,

Thanks for the kind comments. I used to put out some pretty bad stuff in my younger years; something about getting older and wiser. I like to do things once and then be done with it. Same work ethic pretty much everyone on this forum has; we're in general not in a time crunch to get our projects done, so just take the extra steps and time to do them correctly and enjoy using them instead of having to repetitively fiddle with them.

Our son was making the cabinet below in his senior year woods class in high school. Imagine 30 kids in a class competing for the one table saw, one router, one band saw, etc. Successful day for the instructor was everyone going home unhurt. He was overwhelmed and didn't have the time to teach the kids how to properly set up their jobs and do nice work. Our son (Steven) ended up bringing his cut pieces home to our shop for the final assembly.

I remember him starting to glue things up, "Wait, have you sanded the boards yet?" Of course not. "Steven, they're a lot easier to sand loosely than after they're assembled." Then the gluing started again. "Wait, have you dry-fit the cabinet together yet?" Of course not. We dry fit it and squared up the outer box with a carpenter's square. "Doesn't the shelf at the bottom of the door look crooked? "No, I know it's all cut correctly!" Quick check with a machinist square showed it was off. "Hey, if the cuts are correct in the side panels, we should be able to set them face to face and all of the dadoes with be perfectly lined up." Nope, off by 1/8" . . . "Steven, a tool and die maker at work told me once that the sign of a good machinist/woodworker is how well they can hide their mistakes." We recut the dadoes and made a new bottom shelf with a thicker board.

Long story longer, I held out my hands at arm's length and said "if you do a nice job on this cabinet, which is a Mother's Day present, it could hang on this wall for 50 years which is this long." Then held my thumb/index finger about 1/4" apart; " in the grand scheme of things this is the scale of how much time you'll spending making the cabinet. Instead of spending this amount of time, (cue to spread thumb/finger to 5/16" apart) spend this amount of time and you'll be proud of your work."

Sorry to get so long-winded and preachy, but I think we all appreciate seeing someone else's work when it's done well. I get inspired seeing the work other guys do on this forum and wish I had their abilities. Makes me rethink my own projects to make them the best I possibly can. One thing I love about this hobby is there are more than one way to do something so we all have chances to continually learn something new.

Thanks again, Bruce


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OK, now that we have the die for the parachute men done and punched out a couple hundred, on to the next step. I posted in the POTD string making a 5/8” punch with a less aggressive “prick” on the end. I think for the most parts, folks punch holes wanting the hole, not the slug. In my case, I want the 5/8” slug. I’ve made the slugs in the past using a 5/8” hollow core punch. That requires swinging a 2 lb. hammer whacking the chipboard on a board on a concrete floor. The 5/8” punch press method is much easier.

The parachute men get a chipboard washer at their waist which requires a 1/16” x 3/8” slot in the middle of a chipboard washer so it slips up over their legs. In the past, I made the slot taking two hits with a 1/16” x 0.325” punch. Found a 1/16” x 0.395” punch on eBay for $17 delivered. Bought the punch, made an adapter to use it on my Roper Whitney press and now can do the slot in one hit.

But how to center the slot in the paper disks? The press uses a die carrier that has a concentric ring to the die hole area on the perimeter. I thought about boring a piece of stock to fit the perimeter, but went with a much simpler approach that worked out pretty well. Instead, the fixture is a flat plate with a 5/8” hole for the disks. The plate has 3 dowel pins in it that are at the same radius from the center of the die carrier as the perimeter. Theory in use was to set the plate on the workbench, load the disks in the hole in the plate, set the plate on the press and hold the dowel pins up against the perimeter of the die carrier, then punch away.

My mill’s DRO has a PCD function which puts evenly spaced holes on a circle/arc. The diameter of the die carrier perimeter ring is 3.012”, was using ¼” dowel pins so went with a diameter of 3.262” so the inside edge of the dowels would touch the die carrier ring. Told the DRO to do 3 holes starting at 210 deg. and finishing at 330 deg. Before drilling into the aluminum plates intended for the final fixtures, I made a ¼” luan prototype. As luck would have it, my math was correct and the prototype fixture worked great! So well that I contemplated using it as the final fixture, but the aluminum was already cut to size so held the course.

After the slots were punched, the disks were soaked in a jar of polyurethane and paint thinner, then spread out on a piece of hardware cloth to dry. The original paper washers were pretty stiff, the urethane soaks into the chipboard disks and makes them stiff like the original part.

Then on to the pool table with some wax paper on top. The disks are slid in place and a couple of beads of tacky glue fasten them to the men.

The top of the parachutes get a 5/8” diameter black paper washer on either side of the material and a brass eyelet. Punching was done on the RW #218 press. Now to put in the 3/16” center hole for the eyelet.

I didn’t have a 3/16” punch and die on hand so did a POTD to make up the pair. Made a similar fixture to the one described above to center the disks on the 3/16” die. I went with two fixtures as the height of the dies were different by > 1/4”. The 3 dowel pins touch off on both the outer diameter of the die carrier and the surface of the carrier. So the pins are at different heights on the two fixtures by > ¼”. I could have made adjustable height pins, but went with two separate fixtures instead.

I cut a small hole in the parachute material, feed an eyelet through a black paper washer, feed the eyelet through the hole in the chute, and then add a second backer black washer. Use an eyelet crimper to set the eyelet.

Next it’s glue the struts to the chute material corners. Two of the struts get a short length of string glued/taped to them ahead of time which is fed through holes drilled through the parachute men’s shoulders. Once the glue sets, the corners of the chutes get a piece of ¼” masking tape wrapped with a thin film of tacky glue on the outside to keep the tape from unrolling. Once that’s dry, the string is fed through the holes in the men’s shoulders and glued/taped to the opposite side strut. I use a UV activated glue for tacking into place, both of the string to the struts and the struts to the chute material. The glue is wonderful stuff, comes out like gel superglue and stays in that state until a UV LED is shined on the glue which instantly sets it up.

Well, that’s it! It’s still a time consuming process, but the fixtures and punches mentioned in this string have saved me a bunch of time and make for a more consistent part. Thanks for looking!

Bruce

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You can buy die sets, which usually are made up of top and a bottom platten these usually made of steel or cast iron. The sets are normally fitted with two guide pins and bushes at the two back corners, Sometimes you can buy second hand dies that are worth repurposing at a modest cost. Small die sets would range from a few hundred dollars up to maybe a thousand for new ones. Of course you can always make your own.

The standard pattern is a top and bottom platten, with two guide pins and bushes at the rear corners. you can find plenty of pictures on google.

It is of course important that the two platten plates are flat and straight, and thick enough to retain their dimensional stability. If using steel I would suggest at least 1/2" thick for the work you are looking at. After machining both plates to flat and parallel, you can tack weld them together in a stack for the next operations. The holes for the guide pins and bushes are ideally machined in one operation to make sure the are perfectly aligned Using a mill if you have one. Mark out where you want the pins to be, leave at least half the pin Dia between the finished holes for the bushes from the outside edge. While in this set up it is a good idea to bore a hole through both plates in the centre of the plates this will assist in lining up any punches and dies that you make. once the holes are done you van separate the plates , but make sure yiou mark them as to which way they go

I would suggest 1" pins, with a 7/8" step where they locate in the platten. The pins usually are fitted to bottom platten and the bushes to the top.

The pins should be of such a length that they are just engaged in the bushes at the top of the stroke, but not too long that they interfere with the ram at the bottom of the stroke. If it is necessary to make shorter pins that do remain engaged with the bushes for the full stroke it is advisable to make a slight taper at the top end of the pins to assist with locating the pins.

When making the pins use a solid 1" bar of steel. machine a small step at one end to be press fit in the 7/8 holes in the bottom platten. make the step slightly, about .010" less than the thickness of the platten. At the other end of the pin make a slight taper where it engages with the bush. The taper only needs to be about an inch long and only a few thou undersize at the end. It's also usual to cut a few ,2 or 3, shallow grooves in the pins near teh top, these will hold oil and help with ongoing lubrication.

The bushes are usually made from cast iron, bronze would be ok for your use. They will have a one inch hole though the middle and have a 1 1/2" step machine at their base again make this a few thou less than the thickness of the polatten. the rest of the bush is up to you, be guided by the pictures on the internet. It is usual to make a good radius at the top of the bush where the pin enters. I would make the wall thickness of the bushes at least a 1/4" maybe 3/8"

Both the pins and bushes should be secured with a grub screw from the side or back of the platten. When machining the pins and bushes it is important that all machining on each item is done in one setup as they must be concentric. the hole through the bush must be bored not just drilled, and ideally reamed to size. the pins and bushes should be a good sliding fit.

We can discuss making the punches and dies in a few days.
 
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