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

[r3i]

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

Thanks Malcolm

I'll keep a watch on their site.

[malc-c]

Thanks Malcolm

I'll keep a watch on their site.

I've located the thread and forwarded details to my contact at Belting Online. If I hear any news on if they are going to offer a kit I'll let you know

[JamesF]

I keep returning to this thread and pondering on doing the conversion for both my HEQ5 and NEQ6

The 9:47 reduction for the HEQ5 kit does look a bit fierce. That is a very small primary drive gear. I found myself wondering if it would perhaps be a better solution engineering-wise to use the mounting for the original idler wheel and use two belts in a compound train to go something like 12<->24:18<->47.

I guess it really depends on how much load is on the primary in the first place.

James

[1parsec]

Hi James,

I've been looking the same thing to use the idler position to make a compound reduction belt mod for my HEQ5.

I'm not at all worried about the loading on the small pulley of a 9:47 set. The torque from the stepper is never going to overstress the belt.

I'm more concerned about the wrap of the belt over individual teeth being 'lumpy' on the 9 tooth pulley and the transmission not being all that smooth.

The main issue ith the 9:47 route is boring the 9T pulley to fit the motor and ensuring perfectly concentric. Is so difficult to 'clock' a stock pulley accurately.

The off the shelf mod kits seem to also suffer in this regard.

So here's my plan. To fully machine my own 9:47 set . I can machine the pulley teeth and the bore in 1 operation on the same machine from

bar stock which will just about guarantee perfect concentricity.

The design will incorporate a longer mounting sleeve on the back side of the pulley which will also help maintain straightness and true running.

If that doesn't deliver a good improvement, I'll look at a compound belt drive as a second step and see how that compares.

What do you think ?

Dave.

[JamesF]

Machining the 9-tooth pulley in one hit seems like a good plan. I drilled out a similar 12-tooth pulley for my 127 Mak focuser mod and there wasn't much of the hub left then. The 9-tooth must be even worse. Doing the 47-tooth as well may be overkill, but if you have the kit to do the job accurately then why not?

Please do post pictures if you go ahead. I'd love to see it.

James

[Fred_76]

Here are the pictures together with the mod tutorial in French. It doesn't use Malcolm's kit but the mod is quite similar.

tutorial in french

[malc-c]

Making a solid one piece 9t pulley will be better that trying to bore out one of the commercial aluminum ones. The 12t pulley used in the development of the conversion failed due to the fact it was made in two parts and there was not enough material left in the hub section, hence the move to 4:1 ratio with a 15t motor pulley.

So far I've not experienced any issues with the 1:4 conversion. Belts are holding up, the motors have never stalled, and under full slew with both motors running the current draw is typically less than an amp, which is less than when the mount was gear driven.

I guess it's down to the individual's personal observing habits as to which conversion option you choose. If like me you have an observatory with a permanently mounted scope and use a computer to control everything then using a 4:1 ratio and Eqmod suits just fine. If on the other hand you don't use a PC and still need the handset to control the scope then a 9:47 ratio option is the route to take.

My only reservation with using intermediate pulleys is that if you use the standard 6.3mm MXL belts the spacer required to re-fit the cover would be around 15mm thick. If manufacturing this is not an issue then having a one piece stepped pulley may be the way to go. I say one piece as if two pulleys are used there may be a chance of slipping which would introduce backlash and PE - something that these belt drives were designed to reduce.

[JamesF]

Were I to use a compound system with two belts and a pair of pulleys in the middle I'd drill and tap them so the could be fixed together with a couple of countersunk machine screws, I think.

James

[malc-c]

Were I to use a compound system with two belts and a pair of pulleys in the middle I'd drill and tap them so the could be fixed together with a couple of countersunk machine screws, I think.

James

Sounds a good fix to overcome that problem... looking forward to seeing your prototype James

[JamesF]

I freely admit that I am dithering at the moment over which way to go. The benefits of the 4:1 gear ratio very much appeal, but then so does the ability to give the handset to the children and let them get on with it.

James

[r3i]

I've located the thread and forwarded details to my contact at Belting Online. If I hear any news on if they are going to offer a kit I'll let you know

Looks like your suggestion worked Malcolm: http://www.beltingonline.com/heq6-belt-mod-drive-kit-12220?zenid=mjbk8po2bfqdn46ug9efb4uvo4

[malc-c]

That's good news

Goes to show an excellent example of customer service, where a company listens to its customers and no matter how small a market is prepared to develop a solution.

[Nova]

Hi allI can remember seeing this thread back when it started its great to see it is still alive and being added too. Im now in a position to be able to do this mod to my own HEQ5. Im just wondering if anyone has looked at or tried the mod kits from Rowan Astronomy? These kits keep the 9:47 ratio which really apeals to me as I want to still be able to use the handset. Available for HEQ5 and NEQ6

http://rowanastronomy.com/products.htm

[malc-c]

It's quite humbling to see that fololowing the original experiments and kit development for belt drives in both HEQ5 and EQ6, that it's now been taken up by someone who not only has an interest in astronomy, but has his own machining company and can now manufacture these on a commercial standatd.  Personally I don't think there is a large enough market to retire on, but being a direct drop in upgrade rather than the 4;1 ratio like teh kits originally produced will appeal to those who still want to use the handset and get rid of that horrid grating sound the stock gears make.

Personally I like the advantage the 4:1 ratio offers when it comes to dialing out PE - being an even numbers the harmonics are easier to resolve, and having an installation were the scope is controlled via EQMOD it matters not about the ability to use the handset.  But at least with both the producst belting Online and Rowan Engineering offer, all options are covered and thus should cater for everyones needs who is looking at upgrading to belt drive.

[wxsatuser]

Hi allI can remember seeing this thread back when it started its great to see it is still alive and being added too. Im now in a position to be able to do this mod to my own HEQ5. Im just wondering if anyone has looked at or tried the mod kits from Rowan Astronomy? These kits keep the 9:47 ratio which really apeals to me as I want to still be able to use the handset. Available for HEQ5 and NEQ6

http://rowanastronomy.com/products.htm

I have fitted the Rowan kit and it seems excellent.

Cannot comment if it's better because I have never used the mount with the original gears.

IMO it appears very quiet and on my first guiding session I got upto 15minutes with no problem.

Watching the trace on PHD it mainly stayed around the centre line, the only time it wandered off

was when I messed with the camera.