Reliable DIY power ascender

[39Buick]

@Jim G I am curious about you hockey stick looking fair lead. If I am seeing it correctly it appears that the tension of the anchored line keeps the fair lead closed and in the proper position? Or is there something that locks it into place that I am not seeing?
Very nice looking device!
Also like the look of the u bolt but I am not an engineer so will leave that alone!

 

[Jim G]

Exactly as you suspect. When you sit back in your saddle, the right end of the fairlead locks against the stop and you're almost ready for ascending. When you reach height and can unload the ascender, either by reversing/relaxing into your climbing system, or lanyarding in and stepping onto a limb, then the fairlead can be swung outward and the ascender removed.

I say "almost" because usually when you first loop a bight around the pulley, there is some slack (first picture, upper ascender) and the pulley won't grab because the rope isn't fully seated. Most of the time you can remove this slack by just pulling on the tail of your climbing line while starting to ascend. This seats the rope properly into the pulley. A more reliable method is to reverse the drill 4" or 5" while leaning back on the ground, then switch the drill forward. This always removes the slack and you're ready to ascend.

The design of the rope pulley isn't finalized yet - another week or three, maybe. When it is, initial slack might disappear.

Thanks guys. Oddly enough, working on stuff like this is what I call fun.

 

[samsquatch]

Update from my end:
Well wait before the update lemme confirm where I'm coming from: Stock rollgliss R550 with cordless drill.
Update: I'm using the DeFault 996 drill now, this thing is working well. I HAVE FOUND that this drill's clutch will grind as well when running in reverse. It only happens in gears 3 & 2. Gear 1 seems slow enough to not make it grind.

Update2: I'm sticking with the vanilla R550, and my plan is to leave it non-midline attachable, with the stock rope. What I'll do is tie a butterfly in my 11mm line, clip in the R550, then pull the butterfly into place and set my basal anchor. I ascend to the butterfly/crotch, attach my multicender, and detach the R550 - or leave it attached for descent / repositioning.

Update3: If one desires a safety above the rollgliss ( a safety is redundant when leaving the rollgliss stock, but whatever): 28" of Ocean's tied in a Distel hitch is a perfect length. In order to get a proper tie to the shackle, I found a double-ended stainless rod run thru the extra hole in the shackle, and installed some locking nuts to hold the eyes of the Oceans.

Would anyone be interested in a video showing these things? I would gladly, but I won't bother if there's no interest in a non-modded R550 project.

 

[Burrapeg]

. . . Would anyone be interested in a video showing these things? I would gladly, but I won't bother if there's no interest in a non-modded R550 project.

Videos are always welcome!

 

[John@TreeXP]

Would anyone be interested in a video showing these things? I would gladly, but I won't bother if there's no interest in a non-modded R550 project.

I'm interested.

 

[39Buick]

Update3

I think a safety above any of these home brew ascenders is a must. feel free to use what you prefer but not using one is just an accident waiting to happen!
I have a collection of these devices now as I enjoy tinkering with them. Neat little devices!

Exactly as you suspect. When you sit back in your saddle, the right end of the fairlead locks against the stop and you're almost ready for ascending. When you reach height and can unload the ascender, either by reversing/relaxing into your climbing system, or lanyarding in and stepping onto a limb, then the fairlead can be swung outward and the ascender removed.

I say "almost" because usually when you first loop a bight around the pulley, there is some slack (first picture, upper ascender) and the pulley won't grab because the rope isn't fully seated. Most of the time you can remove this slack by just pulling on the tail of your climbing line while starting to ascend. This seats the rope properly into the pulley. A more reliable method is to reverse the drill 4" or 5" while leaning back on the ground, then switch the drill forward. This always removes the slack and you're ready to ascend.

The design of the rope pulley isn't finalized yet - another week or three, maybe. When it is, initial slack might disappear.

Thanks guys. Oddly enough, working on stuff like this is what I call fun.

Again, that's a slick looking device. I appreciate your design and am looking forward to more testing results and perhaps some video footage!

 

[Bart_]

I suspected the arm like structure moved but it looked bolted in which would be much easier beefier construction. 3/8 is plenty beefy it looked smaller in the photo. Bending metal always prompts concern over crack formation so your approach looks like the conservative way. Aligning all the forces is the fun part, no? Do I jest? Only the nerds know for sure. Are you going to try the simulated lathe activity? It can even be done on a decent drill press if you use small point sharp tool bits or make artsy cuts with hand files.

A key concept is the ascender not being life support if you run your climb system above it, but build it like it is life support. IMO.

 

[Bart_]

Here's a new fly in the ointment. Reading the Actsafe info they say not to descend on a fully charged battery because it can overcharge the battery. So their twist grip control fwd/rev has regenerative charging. Perhaps it was inspired by good e-bike speed controllers? Suggests that a bold step would be e-bike-like batteries, controller and a discrete drivetrain. Perhaps this is where the wraptor was/is headed? Act safe claims 20 years on the market. Time flies.

 

[Burrapeg]

Here's a new fly in the ointment. Reading the Actsafe info they say not to descend on a fully charged battery because it can overcharge the battery. . .

This is one reason it is extremely convenient to have a device that is mid-line attachable rather quickly, and used just below a multiscender or hitch arrangement which is the true life support, so that the device can be removed and never has to be used for powered descent. It saves wear and tear on the gear train and power head, and also it is simply quicker to bomb down on one's multiscender or hitch than to power down.

 

[Jim G]

Aligning all the forces is the fun part, no? Do I jest? Only the nerds know for sure.

You are not jesting.

Are you going to try the simulated lathe activity? It can even be done on a decent drill press if you use small point sharp tool bits or make artsy cuts with hand files.

The real shop won't see any of this stuff - something about the needle shape of milled zinc polluting fine woodworking. But the home shop has a decent drill press except for the chuck dropping out when you get too creative. I've adapted an underarm router, circular template and guide bushing to shape the insides of stock pulleys. Has potential.

A key concept is the ascender not being life support if you run your climb system above it, but build it like it is life support. IMO.

My sentiments exactly!

 

[Jim G]

Here's a new fly in the ointment. Reading the Actsafe info they say not to descend on a fully charged battery because it can overcharge the battery. So their twist grip control fwd/rev has regenerative charging. Perhaps it was inspired by good e-bike speed controllers? Suggests that a bold step would be e-bike-like batteries, controller and a discrete drivetrain. Perhaps this is where the wraptor was/is headed? Act safe claims 20 years on the market. Time flies.

One of our cars is electric and the regenerative braking doesn't work until you've drained the battery some. If General Motors can do it...

But I don't see these ascenders as anything more than assisting going up. Most of the fun, at least for me, is descending au natural. I've been clipping in my tail and dropping the ascender back down after reaching height. Perhaps not an option for some, but it works for me.

 

[Jim G]

Sorry for my absence - had to concentrate on making some money. (groan)

The ascender is still performing well with the only outstanding goal being adapting an inexpensive stock pulley for grabbing the rope. The original Maasdam pulley works really well but it's a PITA adapting to the current gearbox, and it's a bit too aggressive in holding the rope. It's designed to grab rope with nearly no load which leads to it holding onto rope when you want it to let go. The Masdaam rope puller features a splitter which forcibly peels the rope off the pulley but that isn't easily adaptable to the current fairlead. Not a good solution.

Stock Pulley #1, hand textured with the Dremel, works really well for grabbing thick ropes, but skinny ropes (under 11.7mm) tend to slip. I had an idea for ribbing the inside of the pulley with tapered end mills, blah... blah... blah, but Pulley #1 is so far out of round, automating the process (truing) made the pulley too large on the inside to grab anything. When you measure runout in 1/32" instead of thousandths, you're in trouble. That experiment failed.

Introducing Stock Pulley #2. Much more concentric with the added bonus of having a rounded gullet and more zinc just where you want it. I ordered three different (smaller) cutters to shape the inside of #2. Keep your fingers crossed. Also ordered Stock Pulley #3 in case #2 is a bust.

Anyway, the latest ascender test was pretty interesting. After the previous test I drained the gearbox oil and found 20 ml less oil than was supposed to be in there. Yikes! Perhaps it disappeared into the gigantic shaft bearings. Perhaps it was never put in. Regardless, refilling with new oil and the correct amount resulted in lower temps and less starting torque. The color of the old oil also revealed a bronze worm wheel. They mentioned something vague about it in the literature, and I was hoping... Now I know for sure. Maybe not a RollGliss yet, but we're getting there.

 

[Bart_]

I have one or two tapered end mills one of which was used to make slanted or non 90 degree face grip ribs inside the sheaves. I think the magic ingredient is the sheaves, balancing grip, wedging, rope punishment, and sensitivity to rope variation. Sheaves are a tedious pain to make. I've only made two with multiple parameters changed, you know, so I can isolate the effect of each parameter. That was an oops shortcut gamble that attained about equal performance according to seat of pants tests. So I don't know the real sensitivities of the parameters.

Are you just getting different tapered end mills? I also have taper pin reamers but I don't think they could handle much side load, although they're small for texturing purposes. Have you considered ball nose mills? Here's an idea - one pass with a hogging mill to leave a texture. Happy cutting.

 

[treegongfu]

Amazing!

 

[Jim G]

I think the magic ingredient is the sheaves, balancing grip, wedging, rope punishment, and sensitivity to rope variation.

I agree and thanks for the insights. It feels like I'm following you down some of the same paths. Unfortunately I just don't have the machinery to make sheaves from scratch, but the stock pulleys are OK for now. Below is my rig for shaping their innards. (Stock Disclaimer: Don't try this at home.)



This is stock pulley #2, the one with the rounded bottom made by Congress. The tapered end mill is 3 flute, 15 degrees on a side. This pulley worked a little better than the one carved with the Dremel, but only because it's narrower on the bottom for gripping thinner ropes. It still doesn't grab the 11mm ropes as well as it should. For a couple samples (Kernmaster, Mercury) I had to remove the fairlead stop to prevent slipping, which essentially turns the rope into the stop. This seems to put an extra strain on the gearbox and drill.

All of the other ropes worked well enough with the thicker kernmantles working the best. My favorites among climbing lines are Xstatic, Drenaline, and Scandere. For a dedicated ascending rope it's hard to beat the 1/2" HTP Static with 1/2" Atlas not too far behind. The thicker, stiffer ropes not only increase the pitch diameter, making ascending faster, but their cross section gets less mangled by the pulley. Rope stretch isn't an issue since it's all removed once you leave the ground, and the steady pull of the ascender doesn't bounce.

I'm officially declaring the gearbox as fully broken in. Last weekend it ran through another 600' of ascending/descending, and one of the starting torques, with 200 lbs. on the line, measured only 10 inch-pounds. That's the lowest measurement on the torque wrench. Consider there could be more than a hundred cordless drills on the market with torques over 400 inch-pounds.

The gearbox manufacturer included parameters for when the gearbox should be replaced based on initial backlash, aka slop in the gearing. At the edge of the rope pulley it first measured around 1/16". After all the testing it still measures around 1/16". According to the instructions the gearbox is worn out at 4x initial backlash. My guess is around 50,000', but who knows. I still don't know how this ascender works with loads over 200 lbs. Maybe the next test is adding a few more cinder blocks to the stack after breaking out the steel toe boots. Ouch!

 

[Bart_]

MacGyver move over. Nice jig. I got worried about edges where I made cuts so I filed a small round at the "flash" edge points or where the rope could contact. I see 12 marked spacing, want to try 24 based on the relatively large flats between cuts? Hoping not too much strength lost in doing so.

I can see the advantage of a taper mill because it has smaller diameter at the end where the pulley groove circumference is smaller and more crowded. Now if they made ball nose taper mills you'd get nice bottoms on the cuts.

If you try a hogging mill you would do a side cut with mill axis tangent to the pulley (oops- not diameter) circumference, moving the cut from the bottom of the groove out to the pulley edge, just a light skim 30 or 40 thou. This would make a spoke pattern probably with quite a fine texture depending on the mill. Matter of fact you could use a single point cutter like a boring bar and cut one texture line at a time, tedious but with fine control of spacing. Better jig design drops time, looks like yours is pretty quick. Gotta have time on your hands for the single point fine cut approach.

Really enjoying watching your project.

 

[Jim G]

MacGyver move over. Nice jig. I got worried about edges where I made cuts so I filed a small round at the "flash" edge points or where the rope could contact.

Thanks for the kind comments. The weird thing about zinc is it leaves no burrs that I could feel, but I turned the pulleys on the lathe both directions with a little sandpaper anyway.

I see 12 marked spacing, want to try 24 based on the relatively large flats between cuts? Hoping not too much strength lost in doing so.

The 12 spacing is mostly due to laziness - it was easy to lay out using the indexing head on the lathe. The Maasdam pulley uses 16 grooves. I think 24 would be fine and would be easy with the current jig by loosening the end nut and rotating the pulley 15 degrees after cutting the first 12. A better way would be using a pin instead of the router's guide bushing, which would allow cutting all 24 in a single pass, but the 12 grooves are good enough for the fatter ropes.

Not sure about strength. I purposely cut the grooves as deep as possible to push the envelope a little, and then tested the whole ascender to well over 1000 lbs without any deformation.

If you try a hogging mill...

Thanks for the suggestion and I'll try it if I get the chance. I'd also like to try an aluminum pulley if I could find one the right size.

Better jig design drops time, looks like yours is pretty quick.

It is, and it could be easily upgraded with a ground shaft, linear bearings and a steel template if you needed to make a bunch. That said, I think it was your idea to use a drill press, and with a custom cutter, could shape both pulley flanges in just one rotation. About the only thing faster would be a CNC milling machine, but now we're talking some big money.

Thanks again!

 

[Burrapeg]

. . . About the only thing faster would be a CNC milling machine, but now we're talking some big money.

It is not a bad job to cast a pulley like this. Aluminium is easy to melt and pour, and quite a few could be poured in one heat. Anyone with a small pottery kiln can melt the stuff.

 

[Jim G]

I originally wanted to cast the rope pulley - it just made sense. The Maasdam pulleys grooves are cast. Why do all that machining if you don't have to? But I have no experience casting or any of the tools, and once the casting has cooled there is still truing the bore, broaching the keyway, drilling and tapping for the set screw. Machining the stock pulley only takes about ten minutes, and other than the cutter, all the parts for the jig came from scraps laying about the shop.

Now, if we were going to make 500 or a 1000 rope pulleys I think casting would be the way to go. The Maasdam pulley is cast in two asymmetrical parts but as long as the grooves are straight, I'd think you could use the same mold for both sides? If so, would it be possible to cast the bore and keyway accurately enough so further machining isn't necessary?

 

[Burrapeg]

Casting in halves would be the simplest way to go. The grooves are straight on the RollGliss pulley and it could be done in halves. I split mine anyway, to put a shim between the halves so it would handle larger rope. Then just rivet the two halves together. You could cast the bore with a cylindrical sand core but would still need to run a reamer thru it in the lathe for a true bore, and then broach a keyway. No way to cast them that accurate.