HEQ5 BELT MOD DRIVE KIT(Malc-c industries :D )

[Fred_76]

Hi Malcom

I had to increase by about 2 mm the depth of two screw slots on the DEC motor plate (as shown on my photos) to allow enough space to tension the belt. On the RA side, I had to grind off the two aluminium corners of the RA motor bloc to be able to move the motor closer to the worm.

The of centre problem is apparently due to an error in manufacturing (excentricity is about 0.10 mm instead of a more normal 0.05 mm). Tavcso will replace my two pulleys with better ones. This should drop the periodic error by about 4 arcsec.

I did a quick analyse of the PE of the old HEQ5 (black body, with two gears/motor and the horrible gear box), the new HEQ5 Pro (white body, with 3 gears/motor) and the belt drive mod (the one of Tavcso). The chart is attached.

[russellhq]

The chart title says "theoretical curves": is this actual recorded data? As I was surprised by the "smoothness" of the belt mod curve!

[Fred_76]

These are all calculated curves from the geometry of the gears (assuming only ovality), pulleys (assuming only of center) and worm gear. It is a huge datasheet made with Excel. It is not a recorded set of data ! The smoothness of the belt curve should be slightly altered by the belt teeth effect but this does not make a big difference.

All 3 curves are made assuming the same defects on the elements, all starting with the same orientation. You can therefore compare the different designs.

[malc-c]

Fred, If you have the means to connect a laptop or PC to the mount (such as using the serial cable used to upgrade the firmware in the handset or an EQDIR cable) EQMOD has the ability to actually gather data of the true PE which can be used to produce true graphs via a simple EQmod add on. It's well worth doing if you really want to see how much difference the belt drive makes

[Fred_76]

Thanks

Don't worry, I konw how to record the PE of my mount ! If you read my tutorial, at the end you will see the PE of the mount before/after the mod. I prefere to use Excel for that, I like PECPrep to do a quick analyse, but for presentations, Excel is better.

[malc-c]

Since I developed the modification and put a few kits together I'm still receiving the odd request for kits or assistance. When I first put the kits together, Belting Online only supplied stock parts and the machining had to be undertaken by a local company. Now they offer a machining service I have been recommending people contact them direct for the belts and pulleys. For information here are the specifications that I had the pulleys machined too:

2 x 15 Tooth MXL Pulley (AL15MXL025FB) (5168)

Modify Bore to 5mm

1 x MXL Pitch Rubber Timing Belts (4580)

Width in mm 6.35

Belt Length in mm 172.72

Tension Cords Glass Fibre

Material Neoprene Black Rubber

2 x 60MXL025 60 Tooth MXL Pulley Pulley

Modify bore to 9mm - narrowed to spec (hub machined to 1mm, face machined to 7mm, 1xM3 G/S through teeth (60MXL025 Special)

1 x MXL Pitch Rubber Timing Belts (4580)

Width in mm 6.35

Belt Length in mm 176.78

Tension Cords Glass Fibre

Material Neoprene Black Rubber

The perspex CNC cut spacer can be purchased direct from Keith at Morris Engraving - The cost I believe is £10.00 ea plus postage, but I would suggest you contact Keith direct first as material costs may of increased.

You will also need 6 new screws to fit the cover back. From memory these were 15mm x M3.

I've attached a diagram should anyone wish to order the parts from Belting Online

[Oily]

Shame you haven't done one for the EQ5

[malc-c]

Shame you haven't done one for the EQ5

Regret that I have since sold my EQ5 so don't have anything to develop a kit with now

[Fred_76]

It seems that on the EQ5 the two spur gears of each motor have the same number of teeth. Therefore you can use the pulley you want as long as they are both the same. But there is very little place, so you shall use small pulleys (little number of teeth) and small belts (not easy to find).

It doesn't seem too complex but it is not as easy as on the HEQ5.

[Oily]

It seems that on the EQ5 the two spur gears of each motor have the same number of teeth. Therefore you can use the pulley you want as long as they are both the same. But there is very little place, so you shall use small pulleys (little number of teeth) and small belts (not easy to find).

It doesn't seem too complex but it is not as easy as on the HEQ5.

Cheers Fred,maybe something to consider in the future

[malc-c]

Also, I believe there are differences between the Pro-Goto Upgrade and the dual axis motor upgrade which has some sort of clutches above the gears, which may make any belt modification tricky.

Oily, why not have a go at developing a kit for the EQ5 and let us know how it works out

[Oily]

Also, I believe there are differences between the Pro-Goto Upgrade and the dual axis motor upgrade which has some sort of clutches above the gears, which may make any belt modification tricky.

Oily, why not have a go at developing a kit for the EQ5 and let us know how it works out

Finances are a bit 'thin on the ground' at the moment to try and develop something Malc,maybe one for the future.

[malc-c]

Well after dropping a mail to Belting Online they now have a complete kit of parts (excluding the spacer and screws) that can be found via the link below

http://www.beltingonline.com/heq5-belt-mod-drive-kit-12097

£51.52 plus delivery and VAT

For the CNC machined spacer, please drop Keith a line at Morris Engraving http://www.morris-engraving.co.uk/starsharp.htm

[Oily]

Didn't realise the parts were that cheap!How would I go about measuring the pulleys/belt required Malc?I'm guessing you do like for like size wise for the pulleys?

[chrisshillito]

Well after dropping a mail to Belting Online they now have a complete kit of parts (excluding the spacer and screws) that can be found via the link below

http://www.beltingonline.com/heq5-belt-mod-drive-kit-12097

£51.52 plus delivery and VAT

Hi Malcolm,

That's great!

I think Belting online need to be made aware that the kit they are offering is not a like for like replacement of the original gear set and that use of the mount's handcontroller will be compromised.

They really need to make this clear to potential customers and explain that as things currently stand the kit is only suitable for mounts under EQMOD control (or mounts with patched motor controller firmware).

Chris.

[malc-c]

I'll drop them a mail and ask them to make it clear that it's not for use with the handset. All we need now is to convince Synta to modify the firmware in the handset to offer pre set ratios of 4:1, 5:1 and the default 9:47

[malc-c]

Hopefully (assuming I found the correct e-mail address ) I've sent sent a request to Synta to ask if they could incorporate a 4:1 ratio setting in the next firmware update for the handset. - be interesting if they support this project

[russellhq]

Maybe as a result of this, Synta will put pulley's in their mounts! We've already done the R&D for them

[chrisshillito]

Hopefully (assuming I found the correct e-mail address ) I've sent sent a request to Synta to ask if they could incorporate a 4:1 ratio setting in the next firmware update for the handset. - be interesting if they support this project

Its not the handcontroller firmware that needs to change - this is already pruposely designed to be "generic" and reads all it needs to know from the mount and controls accordingly - It is the mount control firmware that need to change. For those with newer mounts, where the mount control board firmware is downloadable, then the download file can apparently be patched to support alternate gearings (look for posts by Jeff Machesky on the EQ6 yahoo group). For those with older mounts I was going to come up with a design for a simple proxy device to intercept the messages between mount and handcontroller and "correct them". Its quite simple to do and I've proved the concept using a PC but haven't got round to doing the real thing yet.

To be honest I can't see synta wanting to actively support follks upgrading their mounts! I'm sure HEQ5 owners looking for extra performance are just the folks they'll be hoping to selll their new "higher end" belt driven mounts to.

Chris.

[Fred_76]

Hi!

I received the new 9 teeth pulleys, better than the previous "off center" ones. Here is the periodic error measured (not simulated) :

[malc-c]

Fred,

I assume that the PE graph is with the commercial kit available for 125 euro that maintains the default SW ratio so it can be used with the handset, and not the 4:1 ratio kit that I used to sell (and now available direct from Belting Online). Just that this thread started as a review of the 4:1 kit that I developed and folk may find that graph misleading if the graph relates to a 3rd party upgrade, and might be better suited in a thread of its own

[Fred_76]

You're absolutely right, Malcom. The PE graph is the one of the Tavcso belt mod I did on my HEQ5.

I however don't believe it would be necessary to open an other thread for this type of mod so that anybody wishing to install belt on his mount will see what's on the market.

[russellhq]

Fred, could you remind us what the difference between the red and blue curves are in your graph?

[r3i]

I assume that the PE graph is with the commercial kit available for 125 euro that maintains the default SW ratio so it can be used with the handset, and not the 4:1 ratio kit that I used to sell (and now available direct from Belting Online).

That's a nice kit that Belting Online are offering and at a decent price. Do you happen to know if they will expand their range to offer a kit for the NEQ6?

[malc-c]

Hi Mike,

I'm sure if someone had the specifications of the re-working requirements to machine the pulleys, and the lengths of the belts used they will be happy to put together a kit. I'll try and locate Gorges original thread and drop my contact at Belting a line