EQ6 belt mod

[George]

Anyone done the belt drive mod on the EQ6? I know there's been a few done as posted on the Yahoo EQ6 users group but the info is very sketchy and Ive yet to find a howto and parts list on the subject.

[ncjunk]

Did you find anything George? I was just having a look at belt drives or conrad gears to try to improve the pec a bit.

[Earl]

Im aware of one that is awaiting PEC analysis.

[ncjunk]

I would be interested in the results on that.

[George]

Did you find anything George? I was just having a look at belt drives or conrad gears to try to improve the pec a bit.

Hi Neil, have a look at the info below, although I asked many times on the Yahoo EQ6 group info was very sketchy at best and eventually I got a email of the guy who started this thread on ICE.

I did some pricing and part number matching which is also listed below, the actual mod is on my never ending todo list it adds up to be a fairly cheap mod £31 per axis for parts (not inc reboring gears if you don't have a lathe). What Im planning todo is RA only to begin with and see how it turns out, if your accurately polar aligned you'd only need RA doing in anycase.

You are aiming for a 4:1 gear ratio, EQmod supports this ratio so your slews and goto's are unaffected with the mod

See this thread EQ6 belt drive mod - IceInSpace

Ive priced up the parts and part numbers as below.

HPC Gears Products - Pulleys and Belts

http://www.hpcgears.com/newpdf/timing_pulleys_2.5mod.pdf

Part number 15T 2.5-8 (15 teeth this replaces gear on the stepper) £8.43

Part number 60T 2.5-8 (60 teeth this replaces gear on worm) £13.03

Part number T 2.5/200 timing belt £9.61

The pulleys need to be drilled to fit. 5mm for the motor and 12mm for the worm.

HPC gears will rebore these for you for a small charge .........this needs to be done on a lathe for high accuracy.

[ncjunk]

We do seem to both have similar todo lists! mine is never ending as well.

I like the idea of a belt drive but I want to make it easily reversible....and it looks like you´ve done your homework on that! I think I will just copy your design so let me know when you are going to start and I will purchase the same set up. That way we can compare notes....and generally commiserate each other when we destroy the mounts ;-D

I do want to buy an encoder somtime and try some control based on actual speed. I am thinking of attaching one through a gear box for testing to get the resolution and seeing what errors this adds in to the system. (I still think something can be done)

So just run it as a monitoring system to begin with. I can get a small encoder with a 2000 step per revolution and I will add a 1:1000 gear box onto it and then see if I can monitor the actual movement against recorded PEC and match the graphs up.

[ncjunk]

...thats the thread I was looking at before I came across your thread on here and thought..I know that bodge it master!

[ncjunk]

Lets do it! go on you know you want to...

[RogerTheDodger]

Hmm, I wonder what bits you'd need for the HEQ5, I like the idea if it improves it and makes it quiter on full slew.

[George]

We do seem to both have similar todo lists! mine is never ending as well.

I like the idea of a belt drive but I want to make it easily reversible....and it looks like you´ve done your homework on that! I think I will just copy your design so let me know when you are going to start and I will purchase the same set up. That way we can compare notes....and generally commiserate each other when we destroy the mounts ;-D

Well the beauty of this mod its non destructive and all the parts will fit without altering the mount.......hmmmm I really want to do this mod but with the dark season nearly upon us I don't want the mount out of action ......damn I should have done this over summer

I may just buy the parts and wait for a extended cloudy period.......

BTW Neil did you add the code for the LDR?......better take this to the relevant thread.

Roger, in the yahoo EQ6 group I think there's people who have done the belt mod to HEQ5's or maybe google

[ncjunk]

I tested some code that worked but didn´t add it in. I have spent the last 24hrs trying to find my solder to finish off the LDR/IR box I was doing. needless to say I found it this morning in the Garage whislt trying to remove my son from my motorbike...

So I need to send a request to HPC for these parts:-

Part number 15T 2.5-8 (15 teeth this replaces gear on the stepper) £8.43 Bored out to 5mm

Part number 60T 2.5-8 (60 teeth this replaces gear on worm) £13.03 bored out to 12mm

Part number T 2.5/200 timing belt £9.61

Edited September 17, 2011 by ncjunk

[RogerTheDodger]

Roger, in the yahoo EQ6 group I think there's people who have done the belt mod to HEQ5's or maybe google

Thanks, I've just applied to that group and will have a look

[George]

This US site https://sdp-si.com/index.asp came in considerably cheaper but they are out of stock the 60 tooth pulley

[chrisshillito]

Hmm, I wonder what bits you'd need for the HEQ5, I like the idea if it improves it and makes it quiter on full slew.

For the HEQ5 you would either have to source belt drive gears with 47 and 9 teeth (if you want continued synscan use) or, if your happy using EQMOD all the time (and want better PEC), you could go for a gear combination giving a 5:1 ratio i.e. 60 teeth and 12 teeth.

As far as I'm aware all the belt drive mods performed by EQMOD group members have been on EQ6Pros.

Chris.

[chrisshillito]

This US site https://sdp-si.com/index.asp came in considerably cheaper but they are out of stock the 60 tooth pulley

Any combination that gives a 4:1 ratio will work - it doesn't have to be a 60 tooth pully - 48 and 12 tooth perhaps ?

[RogerTheDodger]

For the HEQ5 you would either have to source belt drive gears with 47 and 9 teeth (if you want continued synscan use) or, if your happy using EQMOD all the time (and want better PEC), you could go for a gear combination giving a 5:1 ratio i.e. 60 teeth and 12 teeth.

As far as I'm aware all the belt drive mods performed by EQMOD group members have been on EQ6Pros.

Chris.

Thanks for that Chris, I bought the syntrek because I knew I was going to use EQMOD, which I do

I'm going to give this some thought, it sounds worth doing.

[George]

Any combination that gives a 4:1 ratio will work - it doesn't have to be a 60 tooth pully - 48 and 12 tooth perhaps ?

Thanks for that Chris , Ive just noticed on Luke Bellani's thread on ICE that he had to machine the worm housing to accept the new pulleys, I don't have access to a milling machine so gears that will fit in the housing as is will have to be used. Ive asked the question on the Yahoo EQ6 group

As a last resort an end cutter on a pillar drill would probably suffice or even a dremmel for some minor modification if you don't have a milling machine but I'd rather not go down that route.

[ncjunk]

I would prefer not to have to machine anything as i only have a Dremel...which is brilliant but i do use it for stuff its not best suited to. (that would be everything)

[George]

I would prefer not to have to machine anything as i only have a Dremel...which is brilliant but i do use it for stuff its not best suited to. (that would be everything)

Well Neil a bit of good news, if you use 2mm pitch pulleys instead of 2.5mm they will fit in the worm housing without any modification.

See this thread , Ive emailed Filip for confirmation and will post his answer when I get it. Carnt find any UK suppliers of toothed 2mm pitch gears so Ive priced using the supplier Filip gave in his post. Filips mod give's a 4:1 ratio which Chris has confirmed will work with EQmod.

Pictures of Filips mod

https://sdp-si.com/eStore/default.asp

Drive belt:

6R51M082060 GT2 (2mm) Pitch, 82 Teeth, 6mm Wide Neoprene Belt $4.01/Each

Stepper pulley:

6A51M012DF0603 GT (2mm) Pitch, 12 Teeth, Aluminum Alloy Timing Pulley $9.37/Each

Worm Pulley:

6A51M048DF0606 GT (2mm) Pitch, 48 Teeth, Aluminum Alloy Timing Pulley $14.13/Each

Edited September 20, 2011 by George

[ncjunk]

I will have to get those pullies drilled out i suppose?

Looks promising then...i could get them both done.

[perfrej]

Folks!

This is very interesting. I assume that changing the bearings to real SKF (Swedish!) ones is also best to do at the same time, right?

One concern of mine is the flexure of the belts. Any ideas on that?

Looking for a Swedish supplier, and I know that there is one as I did get some 8mm belts and wheels for a project in 2004. I'll let you know what I find.

All the best from cloudy Sweden,

P

[ncjunk]

Not sure on flexure, i believe these modern belts are quite good. But we can always put everything back afterwards if it doesnt work.

Let us know any prices you get P!

[chrisshillito]

Folks!

This is very interesting. I assume that changing the bearings to real SKF (Swedish!) ones is also best to do at the same time, right?

Yes I'd change the worm bearings to SKF - That's a worthwhile upgrade for all users irrespective of belt drive mods as the bearings a quite cheap and you don't even have to take the mount apart to fit them (well I managed to work the old ones out with the mount intact).

Chris.

[fwm891]

Don't know if this link will help with belts and gears etc... I've purchased mini pitch belts from them in the past : Davall Gears > Online Catalogue

Edited September 21, 2011 by fwm891

[daz]

For a non-engineering layman, what advantage does this mod offer?

Ta :)D