This post, dated March 27, 2017, contains two email exchanges between Jerry Walker and Mike Eades of the West Valley RC Mariners (WVRCM) regarding the building of a MM.
The writer of each email is identified.
Table of Contents
Jerry to Mike
We still have just one MM on the pond here in Tucson. Each perso
n who sails it for the first time loves it. It performs surprisingly well against the Victorias.
We have two boats under construction (one by Jerry Robertson – he has communicated with you). We are working up to an order for seven kits from GraupnerUSA in time for an anticipated mid-May avail
We are finding with the two kits we have that the mast diameter is a lot closer to 6mm than to 5mm. Thus, mast fittings aren’t fitting. In general, switching to a thicker mast is problematic, especially for newbies.
The issue with the rear corner mis match between the deck and hull is disturbing, but not an insurmountable problem.
We are finding that with the one boat we have on the pond, built in 2009, that the mast is 5mm. We do not have stays on this boat. It appears to us that in a 5 – 10 mph breeze that the boat shows much more inclination to heal than to bend its mast. What is your thought?
In the list of Graupner parts I see the refererence to servo sizes. It’s interesting to note the significant difference in performance between the base recommendation (C 261) and the C 3341) Is there a general agreement in the USA of which servos to use? Or, at least their capacity.
Of our two kits, one has a main sail that looks decent. The other one has significant wrinkles near the tack. It would not seem possible with a flat sail for that condition to arise. Presumably, this is the basis for your recommendation in your article to replace the sails right away. We are going to investigate the feasibility of making our own sails. We have a member who became quite proficient at making good performing Victoria sails.
I look forward to hearing from you. We are very excited about our MM decision. And, our website is evolving to reflect that excitement.
Mike to Jerry
I am glad to hear your club’s enthusiasm for the Micro Magic is increasing!
I will comment on those of your questions that I can answer however I have not built a MM from recent kits, only the ARTR version. Greg Norris built from a V2 kit and wrote it up for an article in the MM feature in the next issue of Model Yachting. I have copied him on this so that he can add his thoughts.
I did not encounter mast diameter problems with the ARTR version. My original MM had a 5 mm OD mast and I used it successfully without shrouds so I don’t believe they are necessary on any MM.
I don’t know of anyone who uses Graupner servos in the US. I used to use the Hitec HS485HB as sail winch and HS65HB for the rudder. However I encountered some strange problems with the HS485HB in which the servo would suddenly jump about 20 degrees and stay there requiring re-centering of the servo arm. Neither Hitec or I could explain this and I eventually went to the Futaba S3010 sail winch. This required drilling new holes in the servo arm to fit the Futaba spline but after modification this servo has worked well for several years without problems.
There seem to have been some issues with sails in recent kits and ARTR versions, not as well made as the original MM kit sails. While they perform fairly well they don’t look good. I made some sets of single panel sails for my original MM which were quite successful but for my Champ Spec MM built by Mike Weston, UK I bought 5 sets of Graphite sails from John Tushingham. I have since replaced the A suit, due to wear, with an A suit from Catsails UK which are excellent and reasonable priced. Several of our club members have bought from Catsails who give great service.
Hope this is helpful?
I look forward to hearing how your fleet develops and hope to see some of you sailing with us here in Phoenix.
Jerry Followup to Mike
What is the meaning of “Champ spec MM”?
Mike to Jerry
Mike Weston in the UK used to sell and build MM kits and based on his and John Tushingham’s experience developed what he called his “Champ Spec” configuration and built and sold many MM’s to this spec. I bought one to see what he did so that our club members could modify their kit builds to conform to his spec. There is nothing radical but he incorporated several minor refinements that improved the room in the cockpit, ease of locating the battery further aft for higher winds and brought the main sheet adjustment down into the rear cockpit in addition to using the preferred Mark I fin and rudder and Mark II bulb, set back so that the front edge of the fin was 25 mm from the forward end of the bulb. All in all it produced a well-balanced boat easy to adjust and sail. In the article I did on the first ARTR MM I bought from Germany I compared the features of the ARTR version side by side with my Champ Spec boat on which the ARTR design was based.
Jerry to Mike
Using kit parts should we be moving the fin location on the bulb?
We have concluded that we want to get the main sheet away from the hatch cover. One idea is to place a tube at the forward edge of the cockpit that extends just a little above the hatch cover. Thus, the sheet clears the cover and has all of its effect on the boom to be (almost) horizontal.
Perhaps you could find a few minutes to send me a pic of the component arrangement in the boat. Perhaps we can take advantage of your ideas.
On our Victorias we typically made a flat platform that one could attach the battery to anywhere on its length (Velcro) and have it engage the rudder post. Thus, the battery could be moved almost to the stern. We use four and five cell flat battery paks. Are you doing something similar?
Mike to Jerry
Awaiting Mikes response.
Greg Norris Jumped in
In Mike’s first response, he indicated that he had forwarded my email to Greg Norris, the Micro Magic Class Secretary. Here is his response.
I’m happy that you’re making progress!
I liked the new kit well, and I wrote an article about putting it together. That article will be out in the early summer edition of Model Yachting. In the meantime, please call me with any assembly questions. In particular, if you are assembling any carbon edition kits, please give me a call for sure.
To your specific questions:
Graupner has been very slowly but steadily improving the kit. The one I put together had a 6mm mast with a tapered top. The mast was thick walled, and much heavier than I would ever use. I suggest using either an older kit 5mm mast or a ~ 6mm SkyShark 2P. The latter have been the usual choice for MMs for years. They are nice. The 5mm old kit masts are also fine. The current European champion uses them.
Both are easily available: SkyShark 2P – https://goodwinds.com They are a reliable supplier.
5mm old kit masts – I have some of these on order. Should be here in a week or two at the latest. I’ll be out of town from tomorrow through 4/9. They should be here when I return, and I can send you one.
I agree with Mike. I would not race with the current kit sails. I don’t have current websites for Graphite or Cat, and I wasn’t aware that Graphite is currently making MM sails. (Mike will know the answer to the last question and have the CAT website.) The other common choice is VAM (vamsails.com). These are sails made in Spain by a guy named Victor Izquerido. They are the most common European sails. The prices are competitive with everybody else, even including shipping. Victor is very reliable and quick. I think that Cat and VAM are both very good ways to go.
I agree exactly with Mike, though we’ve had no problems with the HiTec 485HB. But given Mike’s experience, it makes sense to go with the Futaba sail servo. I buy all of my servos from ServoCity. I’ve found them to be reliable. (www.servocity.com).
Hope that this helps!
Greg Norris, 970 210-4112