Jump to content

Redshift F3F

Recommended Posts



The parts arrived some time ago, but I have had to finish the Canberra first. I daren't open the box in case I got side tracked.

My initial reactions when I opened the box were:-

  1. The quality of finish is superb
  2. The wings are incredibly strong being double carbon
  3. The fuselage is still very narrow like the Stormbird, and the construction very similar, so there won't be a lot of room.
  4. This model has a square ballast tube for the fuselage, which won't fit my round ballast slugs, so I ordered some 19mm brass bar (3/4" in old money).
  5. When I crashed the Stormbird the fuselage broke near the join. I did think of reinforcing it with some Kevlar when I built it, but never did so. I regretted it. I am going to reinforce this one with some Kevlar, which will make the join between the carbon under the wing and the light Kevlar up front less of a break point. I have bought some 150 gram Kevlar cloth, which is now in situ.
  6. I have ordered some KST Servos for the wings and 2 Bluebird servos for the V Tail, which I have never used before.
  7. I did order a standard 4 pack NIMH battery for the nose but it clearly wont' fit as there is not enough room, so I have ordered a 1600 mah 4 cell instead made by Overlander
Link to comment
Share on other sites

Doc Hammond designs aircraft for a living, puts all his designs in a wind tunnel, and manufactures wings with a new sine wave system. He used to design RCRCM gliders but left to set up his own company because he didn't agree with their policy of making fuselages to flimsy to encourage resale of parts, scandalous! He designed the Tornado, Sunbird etc. What a designer. You just can't resist any of his designs. You get what you pay for - Kevlar and Carbon not fibreglass which is brittle and snaps.


The instructions recommend that the ballast tube should measure 400mm ie 10 x 35mm slugs plus a plug and width of the ply 6mm end caps x 2, but the one supplied only measured 386mm so my slugs are each 34mm, hope that will work.

Doc recommends that you use a piece of Depron or Hard Foam to hold the slugs in but I normally use a piece of dowel with a bolt through it and a nut underneath. I will try the foam method as I have some left over blue foam, which might work. I am a bit nervous of what might happen when it is upside down? Presumably if it is oversize and jammed in we might be OK?

So previously I have always put all the slugs in then balanced the tube, but Doc say measure half way down the length of slugs and mark it. This mark then has to line up with the C of G which is 98mm from the leading edge of the wing.

Edited By Peter Garsden on 29/10/2018 22:10:09

Link to comment
Share on other sites


The ballast tube is supported on 2 pieces of 5mm x 10mm Spruce which is planed and rounded off to follow the curve of the fuselage. It also supports the servo tray, which is good thick and strong fibreglass 6mm thick



If I wasn't so short of length, I would have recessed the end caps then flooded the edges with epoxy and fibreglass powder mixed. As it was I carefully put the minimum amount of epoxy glue to secure them and avoid the slugs binding.

NB, you can use sold brass (very expensive and the route I went) or brass tube filled with lead - which is the option I should have gone for, or Uranium - much heavier but crazy price, and I don't have a supplier.

Link to comment
Share on other sites

Hi Peter, some more on the ballast tube for the Redshift. What I do now is to put the ballast tube in with the opening at the BOTTOM of the fuselage - but I'm not sure which version of the instructions you have. I make up the tube first, work out where the opening should be in the bottom of the fuse, then make a smaller opening so I can see what's going on. Then I splooge the ballast tube itself in. When its cured, I clean up all the edges, sand off the extra splooge and make sure the slugs can go in and out easily. This way the ballast is easier to access, will not interfere with the control rods, and is given another level of security by being covered with the nose cone.

Link to comment
Share on other sites

Well there has been some fiddling and farting around as James says in his instructions to get the ballast tube in, hindered mostly by my putting an extra layer of kevlar inside the fuselage for strength. This narrowed the hole through which the tube would go.

Initially I planed some wood off the sides of the beech supports to make it narrower, but too late realised that the inside shape was like a narrow waisted woman, so when it finally went in, there were gaps between the sides and the inside of the fuselage.

Eventually I got a round Permagrit tool to dremmel away the high spots in the kevlar to eventually get it in. What a phaff.



You can see in this picture how the servo tray stands proud of the top of the sides by about 2 mm. This is because the tube was not pressed down far enough when glued in. In turn this meant that the tube was too high by about 1mm where the wing joiner is meant to go and had to be filed away with another Permagrit file. The joiner does fit now, and I didn't have to grind away to expose the inside of the tube and the ballast which is what I feared.


You can see, however, how I wrapped the fuselage in cling film to protect it from sticky fingers. You cannot protect the front section which has to be wiped with Methylated Spirit before the epoxy sets.

I used slow setting 24 hour epoxy which is essential. 5 minute just peels off as it is too soft. I ran out for the servo tray and used 20 minute with milled fibreglass mixed in which works just as well. Sprinkle enough to cover your pool of epoxy. It makes the epoxy dry much hard to match the density of the fibreglass


Link to comment
Share on other sites

So the tip is to insert the wing joiner when you glue in the tube to make sure there is sufficient gap for it and the tube is pressed down far enough. Be warned.


The tray had to be filed and fiddled with to get it to fit in between the sides with the Kevlar taking up more room than the original, but it went in eventually and is a good fit.

I then applied clamps to bed it down onto the beech rails. This adds a lot of strength to the fuselage.

As with all Doc's designs there is not a lot of room for error.

I have worked out, however that my battery fits a treat, better than the Stormbird because I have gone for an overlander this shape

I went for the bottom version which fits just fine. It has been pointed out that a LIFE 6 volt would have been better but I haven't bought the right servos for it - next time.


Link to comment
Share on other sites

I think I am just a Doc Hammond fan. His models all fly like lightening and are very strongly put together. If I see one that cheap I will buy it next time. I have made about half a dozen mouldie's now and they all have to be put together like this one. I don't know where you are getting servo ready planes from Andy but if you buy them new, in my experience, they all need the sort of construction I am going through now.

The main difficulty with Doc's design is that there is usually very little room in the fuselage or wings to cram everything in. Aeroteam models however have more Kevlar and carbon than their competitors and are more strongly built, certainly than RCRCM

For instance, the recommended servo for the ailerons is actually 8mm, so I have ordered this one **LINK** which is not cheap.

I am sure it is all done for the best of aerodynamic reasons.

Link to comment
Share on other sites

Pete - Samba Models (Pike WR, Pike Plus) models and X-models (mini Blade, Mini Carbon Blade, Blade XL), to name but two manufacturers and 5 models that just needed at most a servo tray relieving and pushrods making up. Also note than only one of those airframes needed beefing up out of the box! It's strange that you say that they are more strongly built, then line the inside with kevlar too, or am I getting mixed up? They are European manufacturers though and maybe held to higher standard than the far east stuff.

Nice looking servos yes

Link to comment
Share on other sites

Similar to Andy my Ellipse was half the money and was perfect, screw in the servos and go flying.

Ballast tube? Pushrods? Strength of lay-uo? Already fit for purpose and installed. It looks a nice model Peter but I can't get my head around spending a thousand pounds then having this much remedial work to do before it can be used.

Link to comment
Share on other sites

I think the best person to defend this string is probably the Doc himself who has designed IMHO some of the most aerodynamic, and sleek mouldies ever. He used to design all the RCRCM models eg the Tornado, Sunbird, Vector etc. He left because, somewhat ironically, the fuselages were not laid up strongly enough.

There is no doubt that the model will fly very well without the extra beefing up and I suppose it is just a case of damage protection. I do remember Simon Cocker saying that he does the same with all his models, as did I many years ago when I was learning - I lined my fuselages with extra fibreglass.

You generally get what you pay for. It is the difference between fibreglass which cracks, and kevlar and carbon which doesn't. The carbon, however, in the Doc's fuselages does not extend into the nose so as to avoid signal interference.

I have a Hammer which is sold as an F3F model which was £164 but the wings vibrate in a long hard dive and it doesn't fly fast. I don't know the Ellipse and don't know if it is in the same category.

I look forward to hearing from you learned friends.

Link to comment
Share on other sites

Hi Peter, no defence necessary here.

But let's look.

Expense - I did not realise that the Redshift was so expensive when compared to other F3f models. Is that true? Considering that it uses UHM carbon throughout and already has kevlar in the nose and beyond the wing stubs, plus it comes with a pretty good set of accessories, including servo frames and now including a full wiring harness by the way. I think compared to many others on the market its pretty reasonably priced.

Assembly: I have never found a plane yet that you could just screw in the servos - especially in the wings. The parts that have to be fitted are done that way for a good reason - not everyone wants to use the same servos, or layout or even parts. Some like different servo and receiver positions, some like round ballast tubes, some like wall Lipo batteries etc etc so its wise for a manufacturer to allow the buyer to have some choice even if it does mean a bit of assembly work - but its work that is well within the scope of most people who are advanced enough to fly this type of models anyway. I would have thought that most models need to have the control rods made up and the inner rods ends added.

I'm now an old Phart and I come from a time where there were no mouldies, and not even any kits. You HAD to design and you HAD to make your models from a pile of materials. I was good at it!

Reinforcements: Some people take quite a delight in a brand new shiny model and really want to keep it that way as long as possible. Frankly, as built the Redshift does not need any extra reinforcement but as we have seen its quite possible to put it in. One was crashed into some trees quite violently during the recent world championships and only suffered a small crease in one tailplane - which amazed everyone, and as commented at the time, this was testimony to its good strong construction. But as I said, at least here the owner DOES have a choice.

Model choice: Basically you pays your money and takes your choice. I don't normally buy cheap models or second hand models because I don't want cheap model or second hand performance. My flying is far too important to to me to do that, though I do sympathise with those who's budget may not extend to new models. Personally I want everything I do to be the best I can make it and I'm not really happy to make compromises. Having said that, if you are so inclined, and If you are lucky enough to find a really good second hand F3f plane for three hundred quid, all I can say is WELL DONE!

Last but not least chaps, please always, always, always, remember that we do this for fun. It's not who is afraid of who, who is better than who, or wiser, or any other kind of peeing contest. Let's give good advice, lots of encouragement, offer help, and continue to have the most fun we can have.


Doc James Hammond, Taipei, November 2nd 2018

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...