Jump to content

Bristol Blenheim Mk1V


Recommended Posts

Ken, thats the one, The Bollingbroke was a slightly later version but very similar, might well be worth a visit to see her although I have a trip down to Duxford planned fairly soon were the restoration is nearing completion albeit this time to the shorter nosed Mk1.

Cymaz, your very kind, I guess the projected weight is based more on experience than anything else, although of course I have also used other similar layout and sized models to help me effectively guess what it might be, fingers crossed that it turns out reasonably close but providing it does not climb more than a few pounds more all should be well. cheers and thanks for the contribution, more updates soon - waiting for the glue to dry! Linds

Link to comment
Share on other sites

I think we mentioned that before Lindsay, the mk V, or Bisley. I thought it was used mostly in North Africa, but it's interesting to see that one in South East Asia Air Corps colours, there's probably another interesting story there. The Mercury engines were up-rated a bit to 890bhp and I think the rearward firing guns under the nose were 0.5s rather than 0.303s, I need to look it up!

Link to comment
Share on other sites

Well time for another update on the Blenheim progress. With sheeting now added to both sides of the fuz I now added the rear, aft on the mid top gun turret sheeting that extends from the rear of the turret back to 20mm either side of he fin. this only has a slight curve so not so difficult and just needed pinning and glueing, as the joint is on a slight angle i mixed a little micro balloons filler with the aliphatic that makes it a little thicker in consistence without effecting strength or ability to sand and takes care of any gaps.

s1020066.jpg

Next job was to get a little sheeting on the front underside of the fuz from the front of the bombbay doors to the very front of the nose, I will cut the angles later when dry.

s1020071.jpg

Final job today was to deal with, or at least make a start on the joint between the front windows and the forward sheeting of the cockpit area. This requires a 6mm square section to be cut so that it fits from the mid window frame to the centre strut and also cut away the curved sheeting so that it runs square and parrallel to the top frame. It actually came together quite nicely but was a case of trim to size slowly to ensure all the angles aligned. Once this was in place a small triangular infill of 2mm sheet makes up the gap between the forward sheeting and the ngled frame, this also leaves the gap for a window apperture.

s1020070.jpg

When dry this will be sanded and a little filler added to the seams. Next job is to add some 2mm balsa strip to thicken up the remaining strut frames so the cockpit looks balanced in its structure.

More soon. Linds

Link to comment
Share on other sites

Spent much of today sheeting the underside nose section, this has been done with generally 20mm wide strips of 2mm balsa with the surface dampened and each trimed to size as the angles change. Its time consuming but the end result is pretty good.

s1020074.jpg

Whilst this has had a rough sand, I will leave for a couple of days for the glue to thoroughly cure so it was time to turn my attention back to the cockpit area and added some additional strip around the framework to balance the thickness up, and also added the first of the centre triangular frames. Their is more to do in this area and its just about cutting strip and glueing in place and sanding back to shape. I will work on this over the next week whils working on other areas.

s1020073.jpg

more soon. Linds

Edited By Lindsay Todd on 29/09/2013 19:53:01

Link to comment
Share on other sites

Well time for a further update starting with the sheeting of the fin, nothing too clever here simply 2mm balsa sheet glued in place with a 3mm overlap of the tail post to allow for the shrouded hinge line for the rudder. Eventually I will add some resin filler to the seem when we start to add detail so not so worried about the joint at this stage. I also took the opportunity to open up the tailplane slots in the fuz sides.

s1020076.jpg

Time to do some more sheeting now to the top of the fuz from the cockpit back to the rear gun turret area. I am leaving the gun turret area as this will be getting some special attention later in the build. Sheeting as usual lightly soked and trimed to fit on the centre line top stringer so we have a decent joint. One half is now in place also trimed to the cockpit stringers which still have a little work to do to build up the thicknesses.

s1020077.jpg

s1020078.jpg

more soon. Linds

Link to comment
Share on other sites

Well the top of the fuz sheeting has been completed and work progressed on the front cockpit areas, this principally being laminates of 2mm x 6mm trip balsa to add thickness to the framing and then sanding to shape and then adding 1mm x 6mm balsa to the front cockpit frames to give a T section profile onto which the glazing will be bonded. The next job is a bit of filling and trimming of windows to the correct sizes. The centre cockpit frame that acts largely as a build support has now also been removed except for the upper front curve section. This is beneficial as I can now get my hand back inside the cockpit through the roof hatch to do some detail work, instruments etc later. I guess once the nose is sheeted I can seal and get the old green oxide paint colour out to start on the internal areas that will be difficult to reach later.

s1020084.jpg

s1020085.jpg

Finally added the navigator table to the front inside right of the forward cockpit and infill's to the side structures in the same area all from 2mm sheet balsa. The table is supported on three of four sides extending back to the rear of the instrument back panel.so it is surprisingly strong but will also have some additional struts fitted.

More soon. Linds

Link to comment
Share on other sites

Well its time to do a bit more sheeting on the underside now from rear of centre bay to the tail wheel with 2mm balsa sheet, a little filler to the joints and will be sanded when dry. The underside area is sufficiently wide to have easy access right up to the rear of the cockpit bulkhead to servo and radio installation will have plenty of space. Guide tubes for elevator and tail wheel / rudder closed loop already installed.

s1020113.jpg

s1020112.jpg

This area will have opening doors and a false bottom to hide the radio gear.

s1020111.jpg

Quick bit of wire bending and making up a brass steering arm silver soldered to a brass collet. The other collets act as spacers and the whole assembly will slot into the rear tail wheel tube, closed loop attachment to the steering arm and from the steering arm to the rudder so a single servo will drive both.

More soon. Linds

Link to comment
Share on other sites

Well not too much done from the last update however a few little jobs completed starting with the fitment of the wire tail wheel assembly now connected at the tail wheel end only to the closed loop wire. I use a nylon coated wire for this job simply passed through a 3mm length of brass tube, through the hole in the brass steering arm, back through the brass tube, looped over and back through again and then crimp the brass tube. All the adjustment will be made at the servo end.

s1020119.jpg

Back to the front and time to make up the angled front windows. To start I have added two laminates of soft 6mm sheet to the inside face of the lower front skin either side of the central strut to increase the thickness to allow the curvature to be sanded. A further laminate of 3mm was added to the inside of both sides for the same reason. when dry the angle was sanded to ensure a square off contact face for the 2mm sheeting that is then cut to size and glued in place. On the first side I marked out the window aperture and cut this out, for the second side I glued the sheet in place first and will cut the aperture later as the timber is a little fragile when handling before it is glued in place. When dry the front can be sanded to its final shape.

s1020117.jpg

More soon. Linds

Link to comment
Share on other sites

Well with front windows in place, a bit of sanding and its time to get some green oxide paint down into the cockpit area whilst I still have reasonable access with the spray gun and a bit of overspray is of no consequence.

s1020120.jpg

It's funny how a bit of colour really makes elements stand out, colour used is a latex based acrylic and actually has a degree of filler property to it and helps fill the grain a little without adding too much weight and covers really well. I also chose to spray the rear turret bay as this will have small gaps visible around the turret mechanism.

s1020123.jpg

Just for fun could not resist the pilots view shot!

s1020126.jpg

More soon. Linds

Link to comment
Share on other sites

Well I have been thinking a little about the elevator linkage of late, my original idea was to keep both elevators joined as a single assembly however this does present some issues when it comes to assembly and covering later as it would need to be located prior to glassing the tail plane and I just don't like that idea. So the solution is of course a bent wire 'U' shape and as luck would have it my attention to hoarding old bits and pieces present an ideal item for the job so saved me the task of bending one up. This item comes with nylon fixing tabs which will slot and glue into the trailing edge of the tail plane with a centre arm for the elevator linkage all in stainless steel so perfect.

s1020132.jpg

A region around the centre crank has been scalloped away to allow for full movement up and down and then soaked with some thin cyno to consolidate although as we are less than a quarter through the rear spar and the tail will effectively be supported additionally with the fuz this was overkill but piece of mid I guess.

s1020135.jpg

Inside the fuz the centre elevator rod will connect to the linkage - simples. I'll make the rear at this point a removable hatch for inevitable access requirements and servicing inspections.

s1020137.jpg

Next job for tomorrow is to drill and test fit the wire to the elevators, then cut the elevators into there separate parts. More soon. Linds

Link to comment
Share on other sites

Rain and windy so good building weather if nothing else

Today has seen a few little jobs taken care of, the first of which was the construction of a new rudder which is about 2/3rds the weight of the original, then a quick check of the back end assembly by slotting the tail plane through the fuzz, then marking and drilling the elevators for the control link, cutting the elevator halves into two separate items and then a dry fit of everything on the back end leaving just the hinges to be done and the rudder control horn to be fitted.

s1020138.jpg

s1020143.jpg

Next job was to make up a rear hatch for the underside, a couple of scraps of ply have been utilized, one fixed with some tri section to the rear of the tail wheel support box and the other at the rear glued under the lower 6mm square so they are well supported.

s1020146.jpg

A 6mm sheet section is now cut to fit around the tail wheel box and shaped to the fuselage sides and sanded to profile, A couple of screws will fix in place. I added a small 2mm sheet section to the forward area of the tail wheel just to blend thing is when sanded. Next job is probably the rudder control linkage in terms of a fuselage mounted bell crank that the rudder servo will drive and the control lines for rudder and tail wheel will run from this. o we are getting close to thinking about servo positions at least for the fuselage section.

More soon. Linds

Link to comment
Share on other sites

I'm really impressed with your build of this model. I love the way you have built the nose section, very clean and tidy.

I recently scratch built a MkIV using the old BalsaCraft plan. Didn't have the kit, just the plan. My granddad flew in them in WWII as the navigator/WO, and sat in the "greenhouse". So when I built mine it just had to be the MkIV. This was my first ever balsa built plane, and I'm very pleased with the result.

The hardest bit was obviously building the extended nose section, which is ply formers and sheet balsa. Each pane is individually set, and formed by bending around a paint brush. The nose is secured with a couple of 6mm dowel pins and 4x 6mm magnets. The battery sits inside the nose.

It has electric retracts and nav lights in the wing tips.

It's not brilliant, but for my first ever balsa build, it will do!

Daz

Edited By Depron Daz 393 on 14/10/2013 23:34:29

Edited By Depron Daz 393 on 14/10/2013 23:37:27

Link to comment
Share on other sites

Little update, basically it has been time to secure the control rods, slight adjustment of the elevator rod as I found I had it running perfectly central to the wing spar tubes, just goes to show how when you don't measure it's so easy to make a foul up. Easily cured as just needed cutting free and dropped lower into the fuselage which actually creates a little more space. Next job was to make up and mount an aluminium bellcrank for the tail wheel and rudder closed loop, this is mounted just below the spar tubes on two cross member securely mounted to the inner ply crutch and supports a ply plate onto which the aluminium crank is bolted.

s1020147.jpg

Holes are drilled inboard and outboard on the crank, the inners for the tail wheel were less throw is required and the outside for the rudder. On the other side holes are drilled both sides at mid point between the two for the linkage to the servo so I ultimately have a choice of which side to drive from when it comes to installing the radio.

s1020148.jpg

Closed loop linkage now in place but not yet tensioned which I will leave till I get the rudder lines installed as well.

More soon. Linds

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.

Guest
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.

 Share

×
×
  • Create New...