TJIRC mini Q (Konrad's Special Order)

[Konrad]

I recently learned that Jerry at TJIRC is looking for ways to improve and expand his product line. I noticed that he was claiming to have a new lighter weight lay up of the mini Q. I was intrigued as I had a 6 year old mini Q. While I liked the over all model it had some issues that just kept me from finishing it. 

 

I contacted Jerry at TJIRC about a special order lay up of the mini Q. Most of the Special Orders he deals with have more to do with the livery and colors. I actually wanted some rather extensive changes to be made. Key was the placement of the control surface hinges on the bottom surfaces. I was keen to  set up the model with IDS (cross over linkages). This was to add durability as it eliminates all the linkages hanging down from the wing that often gets snagged in the weeds and rocks. I also felt that this might add a lot of performance as the original set up is rather draggy with all the linkages out in the wind and that the push rods aren't placed in line with the relative air flow.

 

Jerry said he could do the mods to the lay up and we came up with a price. Jerry still supported his dealer network and had me place this special order through his USA importer Aloft Hobbies. 

 

 

Edited November 28, 2024 by Konrad

[Konrad]

As I was going to go with the cross over style of push rod (servo arm pointed down and the control horn pointed up) and I was going to try to set up the system as an IDS (Internal Drive System) I knew I was going to violate the rear drag spar. As such I asked that there be some extra carbon added the inner wing skins above and under drag spar adjacent to the servo pocket.

 

I also asked for some clean up of the livery. At one time I built professional race cars. One of the axiom in American racing was that nobody rides for free. As such I don't like ads or livery that aren't paying for the privilege of riding on my vehicles. So I asked that these names be removed.

 

 

[Konrad]

Here is what I received from the custom order with TJIRC.

 

I really liked the clean look of the paint scheme. I set it up to look like a flashing sign as I roll fast going in the vertical. That is the bottom wing is inverse from the top with the black and white being switched. I had TJIRC add the bubble lace to the bottom of the left wing in white. This has worked out great!

 

I was pleasantly surprise as I learned that in the intervening years TJIRC has added some significant changes to the construction of the mini Q. Key amongst these id the addition of carbon over the top of the fuselage bulkhead to hold this arch ridged. Also the bulkhead is now twice as thick ad the 2018 production run (yellow) mini Q I had. This was done to control some wing flapping we saw when we really pushed the mini Q at speed. It also adds a lot of durability against the ground loop.

 

I was impressed to see that the hinge line is now reinforced with carbon on each side. This really stiffens up the trailing edge of the wing ahead of the hinge and stiffens the control surface. Of note it looks like the live hinge id made from durable polypropylene rather than the more delicate Kevlar. This has a slight cost in that the hinge is ever so slightly stiffer than a kevlar hinge (something to think about when sizing the servos).

 

I don't know where the communication breakdown happened but my request for some added carbon on top and bottom  of the drag spar as an alternate load path did not materialize. I'm not too concerned with this as the new carbon reinforced hinge might offer this and that there a large  carbon servo mounting stiffener adjacent to the drag spar.

[Konrad]

My aim with the special order was remove the drag from the push rods that are set 90° to the hinge line and to remove all the servo bulges and push rod hoods. To do this I'm using the Servorahmen IDS. 

 

I'm using Servorahmen IDS with 50mm push rods and the smallest forked servo arm (4mm). But I think one can go as long as 54mm and not bind against the spar. This 4mm might help ever so slightly with the CG.

 

To fit the servo tray I had to sand down the epoxy rake to fit between the upper and lower skins. I also had the remove one of the ledges on one side to allow the push rod to pass over the tray. 

With the way I placed the control spoon (the pin above the control surface part line) I had to remove much of the support spine. I also needed to bend the push rod about 1mm plus. These rods can be bent if heated with a heat gun first.

Of note I set the control surface to droop 1mm or more with the servo centered. I did this to set some differential biased towards more down. Remember this is a flying wing and requires reflex to maintain stability. I think most folks are using 2mm or more reflex. So my flight neutral trim should be about 3 from this position (2mm from profile neutral). I like a lot of down as I like to unload the wing while doing aerobatics. Using differential (more down that up) allows me to do this without needing to move the stick forward too much.

[Konrad]

This post will basically be a photo essay on how I fit servo covers. Key is to use masking tape to expend the lines than make up the opening past the Blank servo cover. This way you can see the shape of the opening when transpering the lines to the cover. The cut the cove to the tape lines. this only leaves the fitting of the corner radiius.

 

[Konrad]

As I had added another layer of glass cording to the bottom part of the bulkhead as an alternate load path. I took the opportunity to bring this glass across the bulkhead and spar part line. None of this is needed, but I'm a belt and suspenders kind of guy! You might see some of this inside the servo window.

I don't know if this is an issue with the molds, but all the mini Qs I've looked at in detail have some issues with the LE fillet at the fuse to wing joint. I think this is a critical area as it defines how the air will flow over a large portion of the wing area. As delivered this can easily be reworked with a piece of 180 grit sandpaper glued to a hard dowel without damaging the paint. 

Now my particular model had a lot of anomalies on the right side of the fuselage just ahead of the fillet. These could not be buffed out and needed to be sanded to remove. Also my nose cone was of a looser fit than what I recall I had with my original mini Q. As I was going to need to paint my fuselage I choose to use this loose fit to point the nose of my mini Q downward to meet the upcoming air.

The only factory set up issue I'd like to see changed for the normal production models is that the canopy hold down rods be left off. These rods made it awkward and a bit difficult to fit the canopy to the fuselage.

[Konrad]

 WOW, she is very sensitive to initial balance and reflex!

I did get her tamed a bit and was rewarded with a fun fast small ship. The surprise to me was how well she flew inverted. 
I have to admit I was a bit uncomfortable landing her. But I think this can be traced to the fact that the mini-Q does not have and lift dump devices, no flaps (crow) or spoilers. This is a simple 2 channel  and I have to learn to fly within the constraints inherent in a 2 channel model.

Like I said I tamed her a bit. I still have a bit of work with the radio programing and I think I might like to move the CG forward. But as it is I'm tickled pink with her performance!

Right now I think my CG is at 23mm from the LE right before the fillet radius. I also think my reflex is rigged at just under 2mm. 
AUW is 335grams with 75 of that being nose weight. I'm using a small 450 2cell lipo for my battery. This actually will fit in the nose cone.

General impressions are that it is time for TJIRC to offer a mini-Q v2 with bottom hinged control surfaces. This offers us a more durable model without the control horns and rods on the bottom to get snagged in the weeds or hit by rocks. It might be a bit premature to say this, but I think there is a performance improvement, less drag.

Now some might say that installing the IDG spoons (control horns) and external bearing support servo tray is more difficult than the classic control horn and push rods. I don't see this as a problem. Yes, you have to think through the whole installation process. But with the guidance I provided I think anybody that has built a molded glider should be able to end up with passable results. This is NOT an entry level glider. As a result the control system shouldn't be set up as an entry level glider.

At the current sale price of under $200 it make a good model to learn how to install internal linkages. With the end result being a real fun sport ship. I have to admit that flying some of my $2K gliders, the price does take some of the fun out of it. The $200 mini-Q does bring the fun back into sport flying. As a side note the mini Q is very durable, mainly as a result of its low weight. While the mini Q is not an entry glider it is a great model to be your first fully molded glider.

Do see your retailer and ask him to special order a bottom hinged mini-Q for you, well until TJIRC offers this as a stocked product. 

Edited December 16, 2024 by Konrad