Resurrecting A Classic Matador.....

[Steve Hargreaves - Moderator]

Hi Mike....seems you've been busy over the past few days.....I see my learned friend Mr Bott has been doing his best to keep you heading in the right direction....!!!

As Chris says there are a lot of unknowns here....specifically the current supplied by the batteries & there ability or otherwise to supply it. I wonder what sort of cells you have in your battery.....you allude to a set of AAA cells in one of your posts & I would seriously doubt the ability of AAA cells to supply anything like enough power to fly this model......

Far be it from me to tell you how to enjoy this hobby but I wonder if it might be worth considering what you want to achieve with this model....to be blunt I'm not sure there is much point continuing with the brushed set up when a few pounds well spent will get you a more powerful & reliable brushless set up that will fly the model successfully.

As an example I think this is the motor Lee Damms is using & along with this ESC & this battery on a 9x4 prop or similar you should be well on the way to a reliable set up that will fly the Matty very nicely. (It might be an idea to wait until Lee has flown his Matador to see how his motor performs before taking the plunge) A wattmeter is well worth the money if you're getting into electric flight....& you will probably need a LiPo charger....a simple unit like this will do but it might be worth spending a bit more if you fancy a prolonged dabble in the sparky side... You will need a few more bits like connectors & prop adaptors & then you'd be ready to go....you might need to do some work on the front of the Matty to fit the motor too....most outrunners bolt to a "firewall" in some way.

Obviously as an alternative you could use one of the IC motors you have instead....my original Matty flew well on a PAW 2.5cc diesel.

Hope my ramblings help & are of use.....

Edited By Steve Hargreaves - Moderator on 14/03/2012 16:08:15

[Mike Etheridge 1]

Chris and Steve,

Thanks very much for all your responses I have quite enjoyed them and have looked forward to all of them.

My original aim with the Matador after it's rescue was to repair it back in the 1970's and use Solarfilm for the first time as part of the repair. I thought I had identified all the structural problems with the plane and had eliminated them by introducing spruce spars on the wing and spruce reinforcement behind the leading edge of the tailplane etc. The whole of the repair was delayed by the birth of my two sons and their early years which meant the plane stayed in the loft for for a long time. Eventually I dug it out of the loft and involved my oldest son in the repair in the hope that he would take up the hobby -he has not! and hence the Matador's return to the loft. Then came the advent of electric flight and I thought the Matador was a prime candidate for electric conversion. I was originally confident I would have no problems as most of my models had flown either 'straight off the board' or with minimal trim. When I took the Matador to the flying club for the first time I was exremely embarassed that it would not fly and did not look like flying and eventually crashed. Others reminded me of the time I had spent on it all to no avail and how I had spent too much time balsa bashing with the hobby and nowhere near enough time flying. So it was back to the loft for the Matador having repaired damage to the fuselage and removed the radio equipment which I installed in the Junior 60. The Junior 60's 27mhz radio had failed at this stage after 35 years!.

Then you guys decided to build Matadors and produce this forum---the rest you know about!

I was convinced if I could sort out the flight problems with the plane then the Graupner motor would at least keep it in the air for a while,but not so to date. ----I think that if I can get the plane to fly one way or the other with a brushless motor or IC engine I will be happy!!!!

MJE

 

 

Edited By Steve Hargreaves - Moderator on 14/03/2012 16:08:43

[Steve Hargreaves - Moderator]

Only "quite enjoyed" them....?? We really must try harder...you were supposed to "enjoy them greatly"....

So what do you want to do then? Will it be brushless or IC.....??

I do wonder about just "upgrading" the battery.....you could just swap to a Lipo but this might kill your little motor & possibly your ESC quite quickly if it pushes too much power through it/them. Also I doubt that your ESC has LiPo support...this means it might allow the LiPo to become too discharged in use & this will kill the new battery very rapidly

Or even simpler just get a suitable NiMh battery.......

There is much we do not know about your current set up though....without more info & details about the current drain its going to be hard to move forward....might one of your fellow members have a suitable wattmeter that you could make use of I wonder....

Edited By Steve Hargreaves - Moderator on 14/03/2012 16:09:14

[Mike Etheridge 1]

Steve,

I have now had time to look at your motor,battery,charger and wattmeter recommendations and feel it is about time I invested in the gear. I will obviously need to ensure that all battery and speed controller electrical connectors conform with those indicated on the wattmeter unit. I will also need to take account of the cell balancing requirements for lipo's and the need to ensure they are properly maintained and kept in fire-proof flower pots---I hope the flowers don't mind!

I did get to look at Lee Damm's brushless motor installation and in particular noticed the bulkhead mount he had installed which may be a pain to retro fit in my Matador.

I was most impressed with the monitoring equipment used by by Chris Bott,I assume he has the gear fitted in his DH Comet Racer a model that appears to have high value? I did see a real Comet racer flying at Hatfield in about 1988 whilst playing golf. It must have been a replica,I seem to remember it was damaged on landing and has not flown recently?

As for my Matador it occured to me I could put it on permanent display after it's first successful flight as the' SPRUCE MATADOR', after all its taken longer to build/re-build than Howard's effort!

MJE

 

Edited By Steve Hargreaves - Moderator on 14/03/2012 16:09:40

[Mike Etheridge 1]

Last Battery Test with Graupner Geared Motor.

 

 

 

Tthe 9.6v Ni Mh packs that have failed to produce sufficient performance to date are made up of 8x1400 mAh cells as indicated in the photo. My proposal is to carry out a ground test with the 10.8 volt 3800 mAh pack as used in the 'Twinstar 2' to evaluate the performance difference. The speed controller is rated between 6-16 volts and the motor between 8.4 and 10.8 volts, so neither rating will be exceeded.

I will measure voltage drops for full engine speed, and when the 0-50 amp DC ammeter arrives, the full load current. If there is a significant power increase I will try out a further flight test with a 10.8 volt battery pack prior to changing the motor for brushless or IC power.

MJE

Edited By Mike Etheridge 1 on 05/03/2012 13:24:04

Edited By Mike Etheridge 1 on 05/03/2012 13:26:35

Edited By Steve Hargreaves - Moderator on 14/03/2012 16:00:49

[Big Bandit]

Hi Mike,

I've been reading only part of the tread, and appreciate the problems you seem to be having with the Matty and the power train your using. I tried the same myself back in the 80's and to be honest, I was wasting my time. Not wanting to throw a spanner in the works, but the geared 400 is only any use on a powered glider, the Matty needs a bit more than that, as I found to my cost .

I eventually ended up using a 6 Volt speed 400 in the same geared unit with 7 x 1.2 nicad cells and a 9 x 6 wooden prop, it wouldn't "pull a boy scout off your granny" so to speak. As brushless motors and lipos weren't available at that time, to the average modeller, I flogged it .

Standard Matty covered in litespan (and I build light), Futaba 16 gram ball raced servo's from the model cars. The only positive was that the power unit fitted the original engine bearers.

As others have already said, "I would personally go for the brushless and lipo option",

My Quiver (48" Quaker flash) about the same size and wieght as the Matty, uses a Blue Wonder 1200 KV motor, and 15 Amp ESC with a 7 x 6 Wooden IC prop, and 1500 2S Lipo, 7 x 4 prop and it flies a dream.

The most recent purchase is a 2812, 1500 Kv motor and a 15 Amp ESC which will spin a 7 x 4 or 7 x 6 prop on a 2S 1500 Lipo at about 10,800 which should do the job. A tenner to £12.00 approx for the Lipo and prop, £12.99 for the motor and ESC from Tonies models and hobbies should do the trick.

There's no denying that a watt meter is worth it's weight in precious metals for setting up power trains, but if you have a couple of suitable multimeters and a clear head for physics, you should have no problems.

Cheers,

Chris.

Edited By Steve Hargreaves - Moderator on 14/03/2012 16:00:11

[Mike Etheridge 1]

Chris-Big Bandit,

Thanks for the response---I had no idea scouts got badges for that sort of action!

You have obviously reinforced what the others have said and its about time I took  notice.

Today I had a chat with a flying club member and told him of my proposal to step up the voltage on the Graupner gear as a final test. His response was to suggest increasing the voltage presented to the motor up to 12 volts and disregard the motor voltage rating and accept the motor life may well be shortened. (I reminded myself that the speed of a motor is proportional to the voltage, and the torque of the motor proportional to the current)

I got on to the website of the battery supplier I had used in the past (www.component-shop.co.uk) based in Bangor expecting to find a cheap Ni mh battery pack rated up to 12 volts that would fit the Matty.Sure enough they do the batteries with various connectors but the prices exceed £30! So it may be better to invest the money in the brushless motor / lipo gear you and the others have proposed.

MJE

 

Edited By Mike Etheridge 1 on 05/03/2012 22:30:02

Edited By Mike Etheridge 1 on 05/03/2012 22:31:10

Edited By Steve Hargreaves - Moderator on 14/03/2012 15:59:30

[Mike Etheridge 1]

Well if noise is anything to go by certainly the 10.8 volt Twinstar battery applied to the Graupner motor makes a lot of difference. I know this cannot be counted as a fair test as the cells of the battery used are of higher capacity than can be adapted for the Matador. I don't think I want to try the 12 volt test until I can determine the current experienced by the speed controller as I don't want to exceed the 18 amp rating, but obviously I can carry out a ground test using a flight box battery or even a car battery.

Assuming a 12 volt battery can be applied to the Graupner motor then I can make up a pack of cells from the component shop with the right profile to fit in the Matador and the extra couple of cells will help shift the C/G forward to 30%. The batteries on inspection would cost about £13.

Even if this does not work well at least I think I will have tried most electrical adjustments to the experiment. I have not of course not looked into propeller changes.

I do find is hard to believe that Graupner would have invested a lot of money into the production of the geared motors that are not satisfactory especially as some electrical manufacturers have indicated to me in the past that it can cost a million Pounds plus to introduce  new electrical components on the market. Also there does not seem to be enough data available to guide modellers on the use of the geared motors and what there is seems somewhat vague. As most have indicated though they are not the way forward-go brushless!

MJE

 

Edited By Mike Etheridge 1 on 06/03/2012 13:00:33

Edited By Steve Hargreaves - Moderator on 14/03/2012 15:59:03

[Mike Etheridge 1]

I have now bought 10no. 2/3 A1500mAh single cells from the Component shop and will make up the 12 volt pack next week for the Matador..

Went to the flying club today as I did not want to miss out on the light winds and mild temperature to fly the Super 60 again. Usually there is a constant sea breeze which does not favour lighter model aircraft.

Whilst at the flying field I provisionally arranged to test the Matador again next Saturday at the club, but unfortunately the 50 amp DC ammeter I was anticipating will take at least another 3 weeks to arrive as the E-bay company supplier is located in China it seems! However I have been promised the use of a rev counter which could be useful. The weight of the battery pack is a concern though, although I do not think the overall weight of the model will exceed Ben Buckle's recommendation. However the Matador undercarriage may struggle to cope with landings and my guess is it will distort on every flight assuming there is more than one!

Just going back on the issue of voltage applied to the Matador geared motor. I noticed on the Twinstar today that the brushed motors are rated at 6 volts and they have coped with 9.6 volt packs and one 10.8 volt pack to date so my guess is the 7.2 volt rated motor on the Matador should function OK on 12 volts-I hope?

Edited By Steve Hargreaves - Moderator on 14/03/2012 15:58:34

[Mike Etheridge 1]

Plane now ready for its 12 volt test, but I am concerned about the 8oz weight of the battery pack installed. However the CG has moved forward just inside the 30% mark. I am tempted to nip over to Croydon airport for a quick flight test but realise without monitoring the electrical readings and prop revolutions the experiment could be doomed to failure without the causes known.

At the flying club last weekend I was embarrassed to note how many flyers had up to date chargers and test instruments.

Despite being a keen sportsman in the past to hand launch a plane now is very tricky for me with hip and back problems . Any attempt for me to run with the Matador could see me in a worse state than the plane!

MJE

 

Edited By Mike Etheridge 1 on 14/03/2012 14:25:24

Edited By Steve Hargreaves - Moderator on 14/03/2012 15:58:10

[Mike Etheridge 1]

Garden taxi test now carried out. There is a significant improvement to the performance, with just a blip of the throttle the plane was off without any hesitstion on the grass---it could work?

MJE

 

Edited By Steve Hargreaves - Moderator on 14/03/2012 15:57:43

[Steve Hargreaves - Moderator]

Good luck Mike.....I hope it flies OK.....

Have you checked the power figures (current mainly)

I have to say that I am worried for the longevity of your motor & speed controller with this set up.....no big deal if the motor melts but if you lose the ESC (again because it melts due to too high a current) then, assuming you are powering the radio with the speed controllers BEC, the Matty will become free flight once more......

[Chris Bott - Moderator]

Good luck Mike, hope it works out for you. I'm waiting with bated breath.

[Mike Etheridge 1]

Chris and Steve,

Thanks for your support throughout!

Your absolutely right without the appropriate circuit testing the whole radio / speed controller/ motor installation could well be in danger. Its the testing issue that kept me at home today. I have had a couple of alarming speed controller failures in the past with the Twinstar. I can remember a few years ago connecting the Twinstar motors with the throttle at zero as usual. However the motors immediately started at full throttle and the plane spun round on the garden table and the propellors decapitated the nose supports on my new glasses that were on the table!

I have a vague idea that rain is forecast for the weekend which could undermine any model flying?

Mike

[Steve Hargreaves - Moderator]

Check how much current is being drawn first Mike.......any more than 15A will spell a rapid doom for the motor......the rating of your ESC should be printed on it somewhere....

[Mike Etheridge 1]

Steve,

The rating of the ESC is 18 amps.

My intention once I obtain an ammeter is to connect it in series with the motor and monitor the current demand from low to high throttle. Obviously if the current rises too high at any point then the whole installation will need to be modified.If as you say the motor will burn out on a running current higher than 15 amps then it would be pointless replacing the ESC for one of a higher current rating without also replacing the motor. If only I could get my hands on an ammeter before the weekend? I can check the battery pack voltage drop with a simple multi-meter.

Mike

[Steve Hargreaves - Moderator]

A proper wattmeter could be in your hands tomorrow morning Mike if you ordered it today....GC are amazingly fast...I ordered a couple of servos on Tuesday & they arrived yesterday.....before the email telling me they were on the way!!!

If you are going to dabble in electric flight a wattmeter is nigh on essential......it can pay for itself in its first useage if it stops you burning out a motor or esc or battery.....

[Mike Etheridge 1]

Steve,

The wattmeter looks a good bit of kit at a very cheap price. However it seems to relate to only Lipo battery systems and specific connectors. My battery pack is NiMh, I wonder if the unit is adaptable.

I been on the internet within the last hour looking for a suitable instrument and of course have the 50 Amp DC ammeter on order from China via E-bay!!!

 

Mike

Edited By Mike Etheridge 1 on 15/03/2012 11:31:57

[Mike Etheridge 1]

Steve,

The DC ammeter has just arrived from Liu Hui only seconds after my last post!!

Mike

[Big Bandit]

Hi Mike,

I fully agree with Steve a Watt meter is something you would not want to be without once you have one. I started out with a number of decent digital 20 Amp Multimeters they are OK, but you can wind up with a bit of a rats nest of cables getting in the way which is exactly what you dont need with electric power and a spinning prop. The Watt meters are tidy simple to use and also good for checking true battery capacities easily.

On the issue of using brushed motors, I always use a 15Amp fuse in the motor feed with the Speed 400's. Auto type fuses are good with 1/4 spade connectors and have definately saved a couple of electric gliders of mine because the ESC was still working and I had control of the model.

Cheers,

Chris.

[Steve Hargreaves - Moderator]

Well...a Wattmeter doesn't know what it is connected to...Lipo, NiMH, lead acid....it really doesn't care......all it does is measure voltage & current & combine the two to give you a read out (it usually shows Volts & amps too!!!)

This wattmeter also seems to double as a balancer for Lipos....this is where you try to ensure that the individual cells in the LiPo are close to each other voltage wise.... Obviously you don't need to use the feature if you don't want too but believe me if you do get into electric flight you will end up using Lipos......they are SO much better in nearly every respect than NiMH cells.....

You will obviously need to make sure you can connect to it.....a wattmeter fits between the battery & ESC so you will need suitable connecors on both ends to mate with your battery & your ESC....what are you using to connect the battery to the ESC at the moment? You will need another mated pair for use on the wattmeter (or indeed your 50A meter from China) Personally I use the 3.5mm gold connectors throughout my fleet so my wattmeter has them fitted too....

[Steve Hargreaves - Moderator]

Posted by Mike Etheridge 1 on 15/03/2012 11:38:03:

Steve,

The DC ammeter has just arrived from Liu Hui only seconds after my last post!!

Mike

Excellent news Mike.......connect it up......what does it say.....?

[Mike Etheridge 1]

Steve,

Ammeter is pictured above, there is even a Bus-Bar link provided for a mains control panel,somehow I don't think I will add this to the Matador! As you can see its an annalog instrument ideal for us old timers!

Any how it seems easy to connect to the plane for testing which I will do this afternoon with a fixed connector and two bits of wire.

Mike

 

Edited By Mike Etheridge 1 on 15/03/2012 12:02:24

[Steve Hargreaves - Moderator]

Blimey...not seen one of those for a few years Mike.....isn't that a DC shunt? You put the current through the shunt & connect the Ammeter across it to read the current flow through it??

Is there a connection diagram with it?? I don't think you can just connect the two terminals of the meter into the battery feed & expect it to read the current.....

[Steve Hargreaves - Moderator]

Just FYI Mike I'm pretty sure the thing to the left of the meter is a DC shunt........ from Wikipedia..

"An ammeter shunt is a special type of current-sensing resistor, having four terminals and a value in milliohms or even micro-ohms. Current-measuring instruments, by themselves, can usually accept only limited currents. To measure high currents, the current passes through the shunt, where the voltage drop is measured and interpreted as current. A typical shunt consists of two solid metal blocks, sometimes brass, mounted on to an insulating base. Between the blocks, and soldered or brazed to them, are one or more strips of low temperature coefficient of resistance (TCR) manganin alloy. Large bolts threaded into the blocks make the current connections, while much-smaller screws provide voltage connections. Shunts are rated by full-scale current, and often have a voltage drop of 50 mV at rated current. Such meters are adapted to the shunt full current rating by using an appropriately marked dial face; no change need be made to the other parts of the meter."

To measure the current you will need to have the shunt "in circuit"......

Apologies if you already know all this.....I don't want you to pop the meter by connecting it directly....