You can get them from the USA https://www.micromark.com/mini-hand-tools/clamps?page=3 Part SKU:60926. $20.95. They are on back order at present. Neat idea using a fine screw attached to the red knob which pushes a plate to hold the plank. If you can't wait then two bits of wood, one the same thickness as the plank, and a fine screw would do the same. If you drill a fine hole in the former a drawing pin would be just as good. I like the bulldog clips with a paper clip(?) idea as there is no need to drill holes, brilliant!
That is much more like I would have expected. The motor is clearly a 6v version and running over voltage accounted for the previous high readings. Hopefully when you get it in the lake the prop will be suitable and the power will be sorted.
Depends what we are talking about. Doug, Colin I agree if we are referring to a metal joggle used to bend two metal sheet edges so they lay flat for riveting or welding. On a ship the planks are joggled (cut) into the edge plank to make a neat joint. Many fine models are spoilt by having the deck planks incorrectly cut at the angle of the edge plank.
Hi Allen Mabuchi no longer list details of your motor and as it is from an ex flyer chances are it has been cooked at some time in its life. I agree it is not easy to check for shorts but a reasonable meter will show any major problems. Your battery sounds fine. Pitch is often marked on the props near the boss but an explanation I have seen on the web: Pitch: theoretical distance the prop travels on each rotation. This is theoretical because water is not a solid medium and the prop slips. 10 to 30% is normal, the lower numbers are found only on hi-performance props, specially prepared. Constant Pitch: the pitch is the same across the entire propeller's working surface, or blade face. Progressive Pitch: the pitch is lower at the leading edge and increases progressively along the trailing edge. Consider a prop that runs in a liquid media with a constant pitch, the tip of the prop rotates faster than the hub. Conversely, if the angle at the tip is lower, the water speed on all prop surfaces will be the same. In this case, the performance is far better. Progressive pitch props offer better planning performance. So if you were to get some graph paper or paper with 1mm markings and set the prop on a shaft over the paper and measure the start point then rotate thro 360deg and measure the finish point this will give you the theoretical pitch. Over the years I have amassed a fair number of props and usually try various before I decide on the best for the model. Try what you have with the 6v battery (looks just right for the model) and see how it sails. From experience I know that this type of model is difficult to get going and all our club models have coarse pitch brass props. Speed will depend on the motor but with a geared motor you should be able to reduce the revs to give scale speed. I look forward to hearing how you progress in a couple of weeks.
This tug makes into a really impressive model and its heritage shows. We have one in our club and it always attracts attention both on and off the water. You must be very proud to have such a fine model in your fleet.
Great to see a scratch built model. The bridge area must be very difficult to make and this model has captured the look. That drive system should give a massive bollard pull. Congratulations on a fine scale model.
Nicely finished model of this now discontinued kit. I like the details about the tug and her career, sadly our river scenes no longer feature the tugs that were an essential part of the docks and shipping of the time.
Really well built model of the Slipway kit. The detail is really good and some excellent pics. I see you put a raised coaming round the rear deck opening, should keep the water out. Congratulations on finishing. Have you another project in mind?
Hi Doug I was referring to watts produced by the battery in the model and the quoted amps of 40. I made no mention of the motor's power rating. The battery looks ok to me and would struggle to give 40 amps with a duff cell. I agree the best course is to suck it and see as is. May sail fine and the motor not overheat.
Hi Allen I did wonder if it was an ex flyer type as it had the gearbox. The markings can help but not possibly in this case. The other major supplier was Johnson but I can't find your TD224. I suspect this will be a high current fast rev motor probably 12v max. To work with your model I think you will be well advised to follow Doug's suggestion and fit a 6v battery. If you can see the windings inside the motor case and they are thick and few then it is a fast and high current motor. The prop looks like a Graupner and is fine pitch and similar models in my club have a nice brass prop of fairly coarse pitch to give a good slow scale speed. The gearbox will allow you to fit a brass prop of similar dimensions to yours. Initially I agree with Doug though, just pop it in the water and see how it performs. With your luck you will probably source a suitable prop from the car boot sales! Finally As the motor is old it could have shorted windings, in which case it's going to get hot. If you have a good multimeter you can check for low resistance between the case and one of the motor connectors. Use the highest Ohms setting you have and rotate the motor shaft a full revolution, repeat with progressively lower Ohms settings. You should have good insulation between the windings and the case, if you are getting any ohm readings chances are there are shorted windings on the armature and the motor is terminal.
Hi Allen Model has come along fine and should look good on the water. Interesting stats especially the stall current. This would rate the motor at 280 Watts with your 7.2v battery Do you know which type of 300 motor you have installed? Many were 6v max but they have versions that go to 24v. There should be markings on the case and you can check the specs at https://product.mabuchi-motor.com/search.html?method=4. I used two 12v versions in my Billings Coast Guard with 35 mm direct drive props on 12v and they were power hungry, drawing about 4amps each. With your reduction unit I would expect the current to be a lot less than the 6.77 amps you recorded. I agree with Doug's suggestion that you sail it and see. I would suggest a quick circle on the water and then check the motor temp.
Hi Ed I notice that your prop shaft sticks out from the hull which may be why the prop is so near the rudder. I treat all plans as guidance notes and trial fit the parts before final fixing. I believe we have all been in your position at some time or another! I agree with the advice already given and believe a thin washer and thinned locknut would give you the clearance you need. This isn't a speed boat so there will not be much stress on the set up but my preference would be brass, its easy to file and won't rust. I have in the past reworked the propeller boss but its not really a good idea, and does tend to spoil the looks.
If you don't knock the rudder on something it may be good for some time. I have used plastic padding (car body repair) to join two plastic mouldings together in the past. I used a shaft and drilled two 1mm holes within the rudder area, put some 1mm brass rod in the holes sticking out each side then placed the two mouldings either side with plenty of plastic padding in between. Leave to dry overnight then clean up the edges the next day. Might save you having to solder!
Hi Ed Sorry but that joint looks decidedly dodgy. I know it wont be seen but the joint looks weak. Did you use some paste flux? I suspect the heat was insufficient as the solder has not run and you run the risk of hitting something with the rudder and breaking the joint. I would try re-soldering. I normally use paste flux and a blow lamp with such large surfaces. Easier to fix now than when you have stuck on the outer shells. If its any consolation I just binned two days work on a wheelhouse I am making for my Confiance tug - it was 6mm short!
Always good to hear of different makes of adhesive that others use. In a warm room most of these types of wood glue set very quickly to a hold state, developing full strength over 12 hours. A far cry from the days of Cascamite! which I recall seemed to take 24hrs, a lifetime when you are 5 years old.
The specs suggest this is suitable and I doubt if you will be exceeding the max speed! I have used small bearings in the past on projects, mainly for model steam, and have had problems with small bearings. Looking forward to seeing the build progress
Ron It'a a 46" model so the wood is the correct size. You have asked about clamps in your post and there are plenty of examples in this blog, you should subscribe to follow progress. The kits by Vintage Models have been around fore a few years and make into a nice model if built carefully as in this model.
Hi Alan Build looking good. Rather than post new entries in the Response column, you can add to the build blog, which will also allow you to give a meaningful title, add more pics and encourage others to respond to your new posts. I look forward to see how you progress.
Useful info on how to fit a bearing. Do yo intend to provide any protection from water ingress or are you relying on the oiler alone? It would be useful to know the specs (max revs) for the bearing, especially if you intend to fit a brushless motor.
As requested I have obtained some pics from Brian Clewes's Hovercraft. The motors are 900 Kv with 80 amp Escs the lift fan is a 7 blade ducted fan, the thrust prop is a 12in x7in cut down to 10in. Battery is 14.8v 5000Ma.
Hi Graham You do have to support the prop shaft close to the bearings at each end. This is vital if you are to avoid a slight imbalance developing into an uncontrolled whipping and as you have experienced, damage to the shaft assembly. The support needs to be firmly attached to the hull and shaft close to the bearing to provide both vertical and horizontal support. The supports should ideally be within 1/8" of the bearings. If you are reinstalling the prop shaft then, as others have suggested, it may be an opportunity to move the motor towards the stern and use a shorter shaft, but still providing support near the bearings.