Thursday, 16 April 2015

Treadmill service on a Bob Simulator

Replaced the belt on a bob simulator :)

Monday, 6 April 2015

in a 180Vdc treadmill motor, what is the maximum Vdc the motor will accept running?

Question  in a 180Vdc treadmill motor, what is the maximum Vdc the motor will accept running?


1) the voltage to the motor is never the maximum, the controller cuts it to regulate the motor speed.

2) there's not a standard rule about the max voltage accepted by the motor, depends on the motor curves. Anyway the motor accepts 300V for example if the controller is in short circuit you'll see the motor running with 300VDC (with no load), and it's not damaged.

3) the motor speed regulation is based on PWM, this means the voltage is 300V "cutted" such as in a cut-phase regulation. 

TM Treadmill controller


I´m trying to repair a board TM5942. I see it uses a transformer with 2 secondaries, I guess they should be around 12Vac, could you check the value of this transformer?

I also see on the connector for panel one signal is coming and another signal is going so the only way is control speed demand is coming to the board but I don´t know which signal is sending the board to the panel.

I see the processor should switch on the relay but I don´t know when because we have only one opto to send a signal from the panel to the MCB.

I see 4 LED:
LVS = ???
RLY = Relay
PANEL = Power to the panel

Can you help me to clear a little bit the philosphy under this board? Thanks, regards,


it's a tx/rx controller which speaks to the console, this is the reason why it's written connect. I don't have much experience on those TM boards as they are not very common.
If you don't have a console to test it, repair is very difficult. In this case I think it's better to give a new controller to the customer. You risk loosing time to understand how it works and then you learn just for a few pcs in your life.

when a treadmill motor is 8cm diameter, do you think it´s not possible 2 hp?

Question: when a treadmill motor is 8cm diameter, do you think it´s not possible 2 hp?


Dear Customer,

the real power of the motor depends on the motor diameter in most part and only a few for motor length.
Unfortunately, there's a big mess on the labels on the motors because some treadmill manufactures asked suppliers to write much more power than the real power.
Also most of the times it's not written if the power on the motor is peak power, continuous duty power, etc.

For this reason we must take into account the motor dimensions and not the motor label. Sometimes we remove the motor label to avoid customers asking why the label is different from their old motor.

For more details about different ways of calculating motor power, please see PDH Course E156 - Understanding Motor Nameplate Information page 19 / 20 (duty cycles + IEC class).

Which is the right replacement motor for treadmill ...

Question: Which is the right replacement motor for treadmill ... 

if you cannot find the exact replacement for a motor, you can replace with a different one, but please not the following

  1. check motor body diameter. The motor body diameter reflects the real available power of the motor much better than the (often fake) labels
  2. check the overall size of the new motor (if too big, it won't fit in the treadmill).
  3. check the voltage rating 180 up to 230 V motors should be replaced with any 180 or 230 motor. 95/110/130 V motors should be replaced with 95, 110 or 130V motor. 95/110/130V motors may also be replaced with 180V motors, but the treadmill won't reach anymore the max speed since the controller will provide max 130V to the treadmill motor.
Don't loose much time on speed rating (see also this article:  ), fixing holes position (you can drill the fixing bracket or fix the motor with metal bands as described in the blog), HP rating (this value is defined by the treadmill supplier and often is fake)

how much is the maximun tolerance we have for treadmill bands?

Question: how much is the maximun tolerance we have for bands?
treadmill walking belt replacement


usually from one edge of regulation to the other is 5/6 cm it means for the same treadmill +/- 10 cm (band).
Normally the regulation is in the middle and the tolerance is +/- 3 cm.  To select the right belt, a customer should check the end roller, sometimes the regulation is not in the middle but on one side.

Please also take a look at this explaining article

Treadmill Hera - electric diagram for inverter HERA 7000

TBR inverter  ( There is no converter )

2 HERA 7000 I 2. HERA 7000  I TREADMILL
TBR inverter  ( There is no converter )

electric diagram for treadmill inverter

N700E inverter with converter

N700E inverter with converter

electric diagram for inverter

Modification parts

1. You should make a new hole to fix new inverter and converter in the frame.
2. Open front cover and Take out power cable from front cover to inverter and put new power cable
3. Fix inverter and converter on frame
4. Connect all cables.

Wire change

1 Open front cover and separate cable from inverter and filter (for XT model) at picture 1 and 2
2 Separate cable at picture 3
3 If you separate cable at picture 1, 2, 3, you can see cable at picture 4, take it away

4 Connect new power cable and connect it to adapter and inverter

Treadmill speed regulation with endex controller

Question: you told me before, endex controllers doesn't need regulation of speed, anyway I see two trimmers on the controller.


one trimmer, Current Limit (A - MAX) regulates the max. current to the treadmill motor which impacts motor TORQUE. More current is more torque, more powerful motor, but may also bring to early damage of motor and controller if the regulation excess motor capability or if there are load problems on the treadmill.

The other trimmer regulates how the lower controller regulates the PWM (speed setting) according to the signal coming from the console. If the speed sensor is installed, this has no effect on the actual treadmill speed, because the console read the speed signal and regulates the signal to lower board accordingly. Let's say if you regulate the speed on lower controller + 10%, the console will send a signal -10% to keep the same measured speed.  

Treadmill speed: when do you need to set the speed

I´ve been reading your blog, I´ve seen sometimes you do adjustings at boards or console to set proper speed settings. When I sell a replacement motor or board I never say they have to adjust something, is it necessary. I don´t want to sell motors or boards without the proper knowledge about what I´m doing..


The setting of speed is automatic on 90% of controllers. Only a few controllers require the user to set the speed.
The most used controllers which need adjustments are:

  • Greenmaster - usually GMD market control boards, because they don't have speed sensor -> in this case, the setting is made with the trimmer speed on the lower control board.
  • Icon - brands Domyos, Proform, Weslo, Nordick Track. This controller has a speed sensor but it is used only to read speed and not to set. -> In this case there's a procedure, which you can find on the blog.
Anyway, the regulation regards to speed and it is not very important, unless for some reason the speed reported on display is much higher than the real speed.

The real issue when replacing a motor and/or a controller is that if the problem was due to lack of maintenance or other problems (such as friction of the belt, damaged motor when replacing a controller, too much user weight compared to treadmill possibility...) it will happen again.

The best would be to check with an anmeter after installation how much is the current with and without load. If the current access 1,5/1,7 A without load or 6/7A with load, it means there's some problem on the treadmill which has to be solved to avoid early breakage of replaced parts.

Newly replaced treadmill motors smells of burnt. How to solve the issue

I sold a new motor (8 cm diameter) to one customer. First he told me the motor was too hot and finally it was damaged (burnt). After that he told me he through away the complete treadmill...

Which tests and maintenance can they do on these cases? It seems the treadmill has some kind of resistence which overload the motor, isn´t it? I only can say running belt and drive belt, is any other thing which can overload the motor?


90% is a running belt problem (too much friction = belt to be replaced).
10% is too much tension on belt (drive or running), damaged (scracthed) deck (running board), damaged rollers (quite uncommon).

Basic tests for treadmills - standard current values

The ideal test is to use a multimeter connected in A-DC and check how much current consumption in different situations.
If the current consumption is high, motor becomes hot, so the problem should be evident.

I'd suggest anyway when there are problems to make sure the customer checks with amperometer how much current to the motor. The reason is that in this way it's quite precise and they can improve and see by themself the improvement.

I usually suggest to measure A-DC (direct current) with no load (for 180V motor this should be below 1,5/1,7A) and with load (for 180V motor this should be below 6/7A), then to remove tension to belt and check again (it must be lower), another test is to walk on the edges (left&right) of the belt. If there is much difference walking on the edges and in the middle, it's because the belt is more damaged in the middle -> so replace belt.

If the A w/o load is high, it worths checking with less tension on drive belt.
If the A reading seems wrong, please double check. The value should be taken on RED or BLACK cables going to motor. As the tension is regulated by PWM high frequency, some multimeters could fail in reading the values.

130V motors usually have a current consumption up to 50% higher than 180V motors.

Why lubricating is not always the final solution?

Let's say the most common problem is the running belt. Until now as a final solution I always found the replacement of the belt (except some cases with evident problems in the mechanics). Some people use lube and the situation becomes little better, but if the belt is old this effect doesn't last much, as the running belt becomes less flexible over time and this has some effect on friction and motor load.

Too smooth rollers causing excessive tension on treadmill running belt

Another mechanical issue is sometimes the roller is too smooth because of long usage. The roller must make friction on the belt, but sometimes it becomes slippery. In this case, the belt has to be tensioned much (otherwise it slips on the roller) and this brings additional load to the motor (and to the rollers bearings). Usually replacing the belts solves the problem because the new belt has better grip on the roller and less friction on the deck (because it's more flexible), while the final solution in case of slippery rollers is lathe machine.

Treadmill motors with different speed ratings

Question: what happens if a customer's motor is 4200RPM and we is replaced by a 4700RPM model?


let's say the original motor is 4200 rpm at 180 V (with  treadmill max. speed of 16km/h) and the new one is 4700 at 180v

  • if the treadmill has speed sensor the console will regulate the motor speed, so it will run at 4200 rpm at about 160/170V and 16km/h -> there's no need of any regulation on the treadmill

  • if the treadmill doesn't have speed sensor (as example Greenmaster based treadmills such as Roger Black), the treadmill will run little faster let's say 17/18 km/h. -> a speed regulation by console adjustment or SPEED trimmer adjustment on motor controller board would be advisable

Treadmill replacement motors available at Parts For Treadmill shop