Descriptions and links to products and services that have either proven themselves on the pond or that appear to have value to our members
Some examples are specific battery paks and their related technologies and specific transmitters and receivers. As a convenience also included in this category is a pitch to join the AMYA and registering your boats with their Class.
You should register your boats with the respective Class Secretary both to obtain a sail number, technically required for racing, though not enforced for our Club racing and to help the Class function on behalf of its owners.
It was easy to choose batteries for our Victoria’s. The preference was five AA batteries (approx. 6 Volts in a rechargeable battery or 7.5 V. in a standard battery), though a significant number of our skippers elected to use four cells (approx. 4.8 V. in a rechargeable battery or 6 V. in a standard battery). The argument for five cells is faster servo movement and increased servo torque, both a boat performance benefit.
Whether you are using four or five cells there is another parameter to be kept in mind. That is the ampere hour rating. An ampere hour (abbreviated Ah, or sometimes amp hour) is the amount of energy charge in a battery that will allow one ampere of current to flow for one hour. So, a milliampere hour (mAh) is 1000th of an ampere hour. As a practical matter the mAh value determines how long a device will run before the battery needs recharging. In the Victoria, I typically used 1500 – 2000 mAh batteries. This guaranteed that I could sail the boat all day on one charge.
A quick divergence. Standard, non-rechargeable, batteries are 1.5 Volts each. Some of our skippers used 4 standard batteries in a container with complete satisfaction. As far as I know, one cannot purchase five cell containers.
Micro Magic Batteries
The Micro Magic ready-to-sail weighs less than one-half the Victoria (860 gm or about 31 oz., less than 2 lb.). The most c
ommon battery selection is five rechargeable AAA’s of about 700 mAh. According to Mike Eades, this will provide several hours of racing time. His view is to use this low mAh battery and change it out during the lunch down time at a regatta. My 800 mAh pak weighs 66 gm., about 2.4 oz. After the pak was assembled and shrink wrapped by Batteries Plus, I sealed all openings with silicon seal to keep the water out.
The following is the configuration and weights of my battery paks for reference. Obviously, the most significant weight variable is the number of cells. But, also n
otice that the weight is also associated with the mAh rating.
5 Cell, 800 mAh AAA = 66 gm (2.37oz) (this is the 5 800 mAh battery pak shown above)
4 Duracel, 1150 mAh AAA in a plastic battery container = 54 gm (1.93 oz)
5 cell, mAh unknown AA= 133 gm. (4.75oz) (my guess on the apparently low weight is lesser mah rating)
4 cell, 2000 mAh AA = 120 gm (4.34oz) (I have two paks at this weight; both Batteries +; so no surprise)
Note that the 5 cell AAweighs 133 gm while the 5 cell 800 mAh AAA weighs 66 gm, a 2.4 oz difference.
Batteries for Battery Paks
My new battery pak for my Micro Magic is composed of five tabbed batteries I found on the Internet. Tabbed batteries make it easier to assemble paks. I started my search for cells wanting Panasonic Eneloop’s. I could not find them. Next I investigated tabbed batteries from any source. The image to the right shows the typical battery appearance that I found. Though t
he mAh rating was given, there was no information upon which to make a quality judgement. Somehow, I
made the decision to purchase them from QRW Solutions on Amazon (Duh! Where else?). Like I said previously, quality unknown. I purchased six cells; the company sent me seven (i hope that isn’t an expression of their expected quality). My total cost was $10.
I have constructed a battery pak using short pieces of wire
as “tabs”. One soldiers the wires to the batteries, preferably using a soldiering gun as it can product high heat very quickly. High heat applied for a second to properly prepared batteries does the job without damaging the cells. Using wire connections is not desireable. It took too long to deal with each soldier joint as the wire wanted to fall off of the battery. There are three choices to this subject if you want to prepare a pak. Buy tabbed batteries, buy the flat pieces of metal shown in the red-background image, or buy tabs with holes as shown in the other image.
Based upon my experience, the first choice is the easy way to go, whether you assemble the pak yourself or have Batteries Plus do it. The second choice is the tabs with the holes. Based upon videos I have watched on the do it yourself approach, they look like the easiest to me.
I asked the folks at Batteries Plus about their opinion about the best AA, AAA batteries. It was Sanyo and Samsung at the top. This needs to be investigated, because when I did a “best aaa battery” i did not see these companies.
Note: all weights were taken on my kitchen scale. I know it is not exactly correct, but for our purposes here it is sufficient.
HobbyKing OrangeRx R610V2 Lite DSM2 Compatible 6CH 2.4GHz Receiver w/CPPM
View the product details at the HobbyKing website and then bu
y it from a USA source that you find searching.
A typical price is $12.00 including shipping and a few day delivery.
HobbyKing OrangeRx T-SIX 2.4GHz DSM2 Compatible 6CH Transmitter w/10 Model Memory and 3-Pos Switch (Mode 2)
View the product details at the HobbyKing website and then bu
y it from a USA source that you find searching.
Pricing varies widely but it appears that it can be found for under $100. Watch the delivery time information as it can vary widely, ie, up to two months (likely coming from Hong Kong).
There are many transmitter choices on the Internet. You want one that is 2.4 GHz, DSMX/DSM2 compatible. An obvious choice is a radio by Spektrum or Futaba. But there are selections on the Internet at very low prices. Ideally you also want your Tx to support Dual Rate/Exponential. This function is used with the rudder to improve direction control.
I found this radio (Tx and Rx) on the BangGood.com website during a casual browsing: (THE QUALITY OF THIS PRODUCT IS NOT KNOWN). Price about $44 with free shipping.
This article contains hints and ideas for building. This document was scanned from the magazine. It’s images are difficult to interpret. But, if used with the Graupner instructions the images become more understandable.
Back in 2015 the new Graupner SJ company had added an RTR version Micro Magic to its product range allegedly based on the “Champ Spec” MM’s built by Mike Weston, UK which incorporated several refinements in construction, one of which I had bought and have sailed successfully for several years. I imported one of the new HoTT RTR versions and built it for evaluation. I compared notes with Ralf Bohnenberger, Germany who agreed with my assessment and fed back to Graupner suggestions for improvements on behalf of the Micro Magic International Class Association.
In late 2016 Graupner USA, through its web site OpenHobby.com, introduced the HoTT RTR version for sale in the USA. This note provides an evaluation of current production which I refer to as the 2017 version.
The shipment, in the customary Graupner blue box, contained a fully finished hull, fin and bulb, rudder, partially rigged mast and booms, a folded card leaf containing sails and a set of decals and an Instruction Manual (Actually in my box there were 5 copies of a Spanish version Manual and no English version. I was able to download and print an English manual from the OpenHobby web site.) The new Instruction Manual is now mainly pictorial and is much improved over the earlier version.
The hull was beautifully finished, painted white with deck and hull well sealed and all components installed except receiver and battery. Several of Weston’s refinements had been incorporated: hatch secured with 5 latches, an extra one at the front, rudder servo offset to provide extra room in the hull, (Figure 1) single steel rod steering arm and rubber boot, main sheet adjustment located in the rear cockpit, flat knob on transom for backstay attachment, (Figure 2) two hooks on deck for jib pivot attachment and 3 position battery location strip. The on/off switch was installed. To complete the hull ready to sail required trimming redundant arms from the rudder servo horn and tiller arm, inserting the fin and bulb and securing with the deck nut, mounting the rudder and adding a battery and receiver.
Reviewing the assembled hull and components revealed several pluses and minuses. The rudder I received was a Mark II model (Figure 3) whereas the earlier version and Champ Spec models used the Mark I rudder, slightly preferred especially in high winds. The fin and rudder were properly aligned and the rudder post correctly located at 210 mm from the aft edge of the fin. The fin and bulb were nicely faired and finished and when installed the depth from base of hull to base of bulb measured very close to the required 135 mm. The earlier version measured 138 mm, any slight discrepancy can easily be cured by sanding down the head of the fin and the rear sloping edge. The set back of bulb from nose to front edge of the fin was correct at 25 mm. However the weight of the fin and bulb was 428 gm compared with the required 420 gm maximum. To meet Class specs I drilled out a hole in the base of the bulb, roughly centered fore and aft and enlarged the hole gradually until 8-9 gm of lead had been removed (approx. 11/32” diameter hole) and filled the hole with epoxy resin/micro-balloon paste (Figure 4). The location of the fore jib pivot hook measured 186 mm from the center of the mast slot in the deck compared with the Class Rules recommendation of 176mm however I understand from Ralf Rosenberger that the MMI Rules tolerate this difference which is also present in several kit built boats. Overall weight ready to sail including a 5-AAA cell 1000 may NIMH battery and a Spectrum AR6100e RX but without the rig was 880 gm. Finally, while the sheet lines were installed and attachment hooks loosely tied but not placed correctly, the line used was quite stiff and not really suitable. I replaced both sheet lines with 50 lb. Spectra fiber line.
The rigging components and philosophy were a mixture of standard MM Racing kit design (standard Graupner gooseneck, deck plate and mast crane, Cunningham adjuster attached to one of the shroud attachment eyes and use of sliding collets on booms for some adjustments) with some of John Tushingham’s “Graphite” rig design elements (use of silicone ring sliders for adjustments, attachment of the jib forestry and topping lift to a small metal ring attached to the jib hangar to ease jib rotation. The mast appears to be a 3-piece construction with a 6mm OD carbon spar from just below the deck plate to the jib hanger and two 5 mm OD carbon tubes at either end. Shrouds are included but are redundant, on my model I used the cut off shrouds for my jib pivot and Cunningham lines which were missing. One annoying feature of the standard Graupner gooseneck has always been the tendency for the gooseneck fitting to slide upwards along the mast allowing the two locating tabs to slip out of the deck plate thus allowing the fitting to rotate around the mast. I devised a simple cure by marking the mast just above the gooseneck when correctly located in the deck plate and winding a collar of Spectra fiber fishing line around the mast just below the mark and saturating it with thin CA glue (Figure 5). Now, when in position the collar maintains downward pressure on the top of the gooseneck preventing it from being lifted out of the deck plate (Figure 6).
The sails are of improved material over the earlier version, white Icarex, but still perhaps slightly heavier weight than desired for “A” sails. Construction however was poor with a large triangular joint half way up the main sail and wrinkles near the main sail head (Figure 7). I assembled the rig essentially as designed for evaluation including use of the metal luff rings.
The finished all up weight ready to sail was 932 gm, still somewhat high. However Greg Norris informs me that substituting a lighter LIPO battery could reduce the weight to 880 gm which would be very much in the competitive range.
I conducted some brief sailing trials against my usual local competition and found the boat performed well, even in light air. I conclude that with a few minor improvements the ARTR version Micro Magic will be an excellent addition to the product range providing new skippers, who don’t want to build from a kit, a competitive boat for racing.