Domanoff Rope serving machine SM4 question

[modeller_masa]

Hi, I got a Domanoff rope serving machine SM4 with full option today. I have question about this great rope serving machine.

 

 

An assembly of the most recent version of SM4 is slightly different from the Domanoff's guide, but I had no big problem.

 

 

This is my modification on current SM4 kit with endless option. I use motor, so I don't need handles. 

 

 

However, it seems the endless option is not fully evaluated its purpose and usage. It is very hard to use the bobbins, and the part looks easily breakable. 

 

 

I would say that the endless option is roughly impractical and experimental function, and SM5 or SM6 may be significantly better than now. 

 

The other functions such as motor driving serving machine work super well. I would say that the SM4 with motor option worths every penny, but endless option is not.

 

Did I understand this machine correctly? Is this a right way to use an endless option? If I'm using it incorrectly, please let me know how to use it. I can't find any guide for SM4 rope serving machine with endless option.

 

By the way, I purchased SM4 because it is cheaper than PL4...... I didn't know difference between rope making machine and serving machine. 🤪 I ordered PL4-4 today... 😂

[wefalck]

I don't know anything about these machines, but the problem is how to hold tight a section of rope, where the serving has been completed. One way is to wind it up onto a spool or bobbin. The same of course applies for the yet unserved part. An alternative would be to wedge the served and unserved part with some sort of collet or similar, but this could damage the serving and squash the the rope.

 

I don't know, of course, how long your masts will be, but certainly the best option would be to stretch out the rope over the full required length, if at all possible.

 

A completely different design would be probably more appropriate for an 'endless' serving machine: the rope should be stretched between two spools, keeping enough pull on it and the bobbin with the serving rope would rotate around the rope to be served. This is the principle used in full-size practice. One would need to advance the rope to be served between the two spools just by the thickness of the serving rope for each turn the bobbin makes. This can be effected by sets of change gears that connect the two spools with the part that spins the bobbin around the rope. Or, today this could be done CNC-fashion with three stepper motors.

[modeller_masa]

I totally agree that this machine needs an improved endless mechanism. In addition, I would say that tension of serving rope is enough in this case. This machine has motor, so I can concentrate on handling thinner thread that covers surface while traditional serving machine requires to turn a handle. 

 

 

Actually, I don't need to take an effort to feed thinner thread correctly. After some trials, I found that this motorized machine performs self-aligning function. Without any effort, thinner thread covers surface of serving rope with zero gap like a magic. It looks really nice and professional. It is the reason I said this machine is valuable. With applying shellac that you posted great tip in the past, now I have perfect 1.00mm diameter serving rope on the palm of my hand. I hope it lasts long.

 

Low tension means more freedom of design. An auto? advancing function idea you commented also preferable. Making a new endless option with auto advancing function is challanging but interesting. Hmm... I need time to investigate other types of serving machines.

[wefalck]

Check out Johann's LA CREOLE building log: he has there a little device to suspend the bobbin with the serving thread from the rope that is being served. This avoids pulling the rope out of shape and advances by itself ...

[modeller_masa]

 

I gotcha and understood what you said. This SM4 kit can perform most of work Johann made, but his machine is more advanced and accurate for specific cases. It will be really good reference for the next step. Thanks, wefalck.

[hornet]

I have an older model of this machine. I improved it by adding another length of threaded rod to the front to hold a reel of thread. It makes the job a lot easier. I simply drilled and bent up two right angled brackets in Perspex then drilled a hole in the front (base) of each of the legs on the serving machine. I bolted on the the brackets then threaded the rod through holes drilled in the top of the brackets. I can change thread reels simply but undoing one of the nuts on the threaded rod and changing reels. 

Edited February 19, 2021 by hornet

[popeye2sea]

I don't think you need to shift the rope while actually serving.  What the 'endless' option provides for you is a way to take up the excess line on either end so that it does not tangle and get caught up in the handles and gears.

The way I use this is to fix the rope tightly in place and serve a length of rope as far as I can.  If the service needs to be continued, that is when I shift the rope to be served further along between the bobbins. Then I can continue serving.

Hope that makes sense.

 

Regards,

Edited February 20, 2021 by popeye2sea

[wefalck]

That's why I at least understood, how the machine works ...

[modeller_masa]

I found that tension is big problem in case of nylon thread. It wasn't big issue when I used polyester thread, but nylon thread definitely needs tension to keep flat feeding line.

 

 

I made feeding guide inspired from Hornet's work. This is very simple feeding table, so I made it almost instantly.

 

 

Locking mechanism is very simple.

 

 

I used two 5.00mm pinewood rods.

 

 

I'm testing serving rope machine with cotton thread as main thread and 0.10mm nylon mono filament thread as sub thread. I gave up to use regular polyester thread as sub thread due to huge pills and ugly appearance. However, nylon thread requires accurate tension control.

 

 

My new option helps hands free, but doesn't help that much as I said it has no tension control. I may be able to add tension control mechanism by weights and friction.

 

https://shipworkshop.com/products/tools/pl4

I found that Domanoff reused the troublesome endless option part from his PL4 machine. It may work great at the machine, but the machine didn't need to tighten bobbins that much like SM4 case. Also, I need to pull and push it 100 times until I complete one serving rope while PL4 needs only once. It is definitely different situation compared to the PL4 case.

 

I agree Henry that the endless option actually works, but it is not ready to sell commercially. I would say that Domanoff needs to redesign the part. It is vulnerable and cumbersome.

 

 

 

Here are assignments.

 

- Tension mechanism on thinner thread. (Difficulty:5)

- Easier and reliable main thread transfer holder. (Diff:2)

- Adjustable automatic main thread transfer mechanism with motor and tension control. (Diff:10)

 

Replacing bobbin holder is the most urgent mission before it breaks soon.

Many thanks to Hornet, Henry and wefalck.

 

By the way, I purchased various nylon mono filaments from 0.12 to 0.33mm. I'm tired of pills from polyester thread...

Edited February 21, 2021 by modeller_masa

[modeller_masa]

 

I found an another point should be fixed. With high tension from sub thread, main thread can be cut while in progress. The blue point is sharp, so it breaks thread and eventually cut it without notification. 

 

 

It happens frequently when I use thin cotton thread, and this thick linen thread on the picture also began to break up. I'll sand it down or paste epoxy bond to make sharp edge smooth.

 

 

I made very simple tension control system powered by Lego.  It really works well. It keeps tension constantly, so it minimize mistakes, makes work easy, and produces remarkable result than human hand. Also, it doesn't give huge tension on main thread, so it prevent cutting failure I explained. I would say that this mechanism can be applied to full auto production machine in the future I'm planning.

 

Here are results.

 

The first result is made of polyester thread. it  was looking good at first, but it got heavy dusts while I was applying shellac as adhesive... Also, it is hard to notify each knots. NOT realistic.

 

The second approach is nylon thread. Much better and satisfying results. First one is 0.65mm with cotton thread and second one is 0.90mm with linen thread. The white and brown pills are from inner core thread which has different color intentionally. 

 

https://www.cargos-paquebots.net/Reportages_divers/LA_RECOUVRANCE_19-09-2014/Images/LR_5644.jpg

( https://www.cargos-paquebots.net/Reportages_divers/LA_RECOUVRANCE_19-09-2014/La_Recouvrance_09-2014-01.htm )

 

This is a picture from real ship. My serving rope looks so real... 🤤

 

[wefalck]

I still think that a kind of travelling steady would be better, that supports the rope being served left and right of the point being served, without pulling on the rope overall. This could travel along a bar underneath the rope being served to support its weight.

 

I don't have a need for served rope at the moment, but have already collated most of the material I will need for the construction of a serving machine. I have a design along the ideas outlined above in mind ...

[modeller_masa]

The travelling steady system is definitely better than this because it can be developed to a full automatic system like a factory machine. However, it may need different (new) design. On the contrary, if I fix and modify this machine a little bit, I may be able to complete semi-auto machine. (That's what I expected when I opened this machine.) 

 

I think new design is out of my ability for now, so I'll stick to modify SM4. Good luck and please show me when you complete the innovative machine, wefalck. (Don't forget to register patent. 😉)

 

- Tension mechanism on thinner thread. (Difficulty:5)

- Easier and reliable main thread transfer holder. (Diff:2 →  7)

- Adjustable automatic main thread transfer mechanism with motor and tension control. (Diff:10)

[wefalck]

I am years away from this ... at about the same time I made some sketches according to my ideas, Johann came up with his solution. Just think of Johann's solution, but rather hanging from the rope being served, I though of guiding/suporting it on a rail. Both ideas have their advantages and disadvantages. Johann's solution is light enough to move along the rope by itself, but requires that rope it stretched quite tightly. In my case, one would need to guide the steady manually, because the friction on the rail would be too big. One could go, however, to the trouble of installing change-gears (or stepper-motors) the couple the progress with the rotation of the rope, as noted earlier.

[claybaker]

FWIW, I have one of the older motorized versions (not sure which one) and I very rarely install the motor. I seem to produce a better serve when I can feel the machine with my left hand and the rope with my right. And if anything gets out of whack I can stop within a single turn - something I’d have to add a foot switch for with a motor (slow reaction time 😔)

[modeller_masa]

 

You're absolutely right. I'm using foot pedal switch, and it is 100 times better than controlling knob.

[wefalck]

I am running all of my machines from foot-switches - they have momentary switches, not the ones that switch on and off with a 'click'. Lifting the foot immediately stops the electricity. I set one in front of the transformer from which I run all the low-voltage equipment.

[modeller_masa]

I learned new word that my pedal switch is called momentary switch. I may need non-momentary knee switch for longer work. 

[wefalck]

I think the knee-switches on home-sewing machines also contain a speed-control, as do many of the foot-switches. I used one for many years, but would not recommend it for most machines. It can be very tiring to hold the foot/knee at exactly the same position in order to keep a steady speed when drilling, milling or turning. I prefer a separate speed-control that allows me to pre-set the rpms.