Maintanence Instructions for Meade LXD55 / 75 Motor Gear Box

Transcription

1 WARPSCORP A publicatin frm the Yah Grup - WarpsCrp. Prviding slutins t prblems, answers t questins and ideas t share amng the amateur Astr cmmunity. We welcme yu at: Maintanence Instructins fr Meade LXD55 / 75 Mtr Gear Bx MOUNTS & DRIVES TIPS & TRICKS SERIES MAY 19, 2006 There has been much discussin regarding lse gears, setscrews, rubber-banding and incnsistencies in the tracking and g-t capabilities f sme LXD55 / 75 munts. While many f these issues have been minimized thrugh mdificatins and adjustments, there still remains the internal mtr reductin gearbx which culd use sme maintanence. This guide addresses the assembly and disassembly f the mtr reductin gear bx, its cleaning and re-lubing and alignment f the delicate encder discs. All mdificatins and enhancements are dne at the risk f the wner and may affect yur warranty. Setup / Tl Check... Tls Yu Will Need: Assrted Allen Wrenches (see pictures) Small Phillip s Screwdriver Wire Cutters / Sharp Scissrs Tthpicks Tweezers Single Edge Razrblade Lubricating Grease Applicatin Paddles (wd cffee stirrers) Allen wrench fr set screws 1-3/32 Allen Wrench Shallw Dish and Fresh Turpentine Old Tthbrush Q-Tips Clear Silicne Glue Ultra Flat Black Paint (ptinal) Red Felt Tip Marker Shrink Tubing / Electrical Tape These are the wrenches that I regularly use in wrking n my munts. The ballended Allen wrenches are available at hme dept fr abut $19.00 a set. They are made by Husky and include the fllwing sizes: Metric: 1.5, 2, 2.5, 3, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10 SAE:.050,1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 3/16, 7/32, 1/4, 5/16, 3/8 The ball end seems t ffer a much better grip n sme f the tiny set screws used in this munt. It has easily remved and tightened set screws that ther nrmal wrenches seem t just spin in. Highly recmmended. Nte: This prcedure can be dne with the encder in place - if yu are careful. Remving the encder requires a very tiny 0.9mm allen wrench and the tiny set screw is easily stripped. If yu try t remve it - prceed with extreme patience and care. Here yu see the bare mtr assembly remved frm it's plastic husing. Ntice the delicate encder (shiny sltted disc n the left end f the mtr). It is abslutely essential that this wheel be straight, clean, tight n the shaft and nearly centered between the emitter and receiver. Centering des nt have t be abslute - just make sure it is nt rubbing against either the emitter r receiver. The white wire blck at the upper left appears t be a remvable plug - it is nt. D nt pull r try t pry it lse frm the bard. Cautin: Cautin: d NOT tuch the encder disc with yur fingers as yu will leave an il residue which will attract dust and pllen in the air. If yu d tuch it, clean it with a very sft, fine brush and denatured alchl r acetne. 1

2 The plug with the red and black wires are the wires ging t the mtr and is remvable. Nte the rientatin f the wires and mark the pin fr the red wire with a red marker. Cautin: This small cntrller bard has several integrated circuits n it and is therefre succeptable t damage due t static discharge. I recmmend tuching smething that is grunded t drain any charge frm yurself each time yu sit dwn t wrk n r handle the bard. In 40+ years f handling electrnics, I've never had a piece f electrnics damaged by static electricity - but yu dn't want this t be the first time. Remve the three allen head screws n the end f the mtr husing where the "keyed" shaft emerges frm the husing. Once these three screws are remved, the mtr will slide ut f the husing. Nte: Take nte f hw the wires are ruted and be careful nt t stress them as yu slide the mtr ut f the husing. After remving the red / black wire plug and marking the red pin, use a small Phillip's screwdriver t remve the 4 shiny screws hlding the cntrller bard t the mtr husing. Be careful s yu dn't slip ff f the screw and damage the bard. Nte: There are 4 very small nyln spacers under the bard n each screw which hlds the bard away frm the mtr husing. Be careful nt t drp and lse these tiny spacers. Once the cntrller bard is remved frm the husing, take a small pair f wire snips r wire cutters and cut the tw wires as pictured. If yu lk clsely, yu can see where the wires have been cut previusly and then spliced and cvered with shrink tubing. If yu cut and splice in this same area - everything will lk the same as a stck setup. Yu will ntice a small metal "dnut" that the wires are wrapped arund. This is a ferrite chke t suppress any RF energy which may be emitted by the mtr wires - causing interference in radis/tv's. Cautin: The cnnectins f the wires t the mtr are very delicate. D nt pull r put un-neccessary strain n these wires. If yu d happen t pull ne lse - it prbably can be fixed by carefully sldering it back t ne f the tabs visible frm the encder end f the mtr. Nte: Since I did nt see the need fr this, I remved the ferrite dnut and thus shrtened the wires cnsiderably. Running the mtrs in huse next t my TV, cmputer, wireless lan and and stere exhibited n unwanted interference. This ptin wuld be yur call. Carefully remve the tw screws that hld the gear cver casing t the mtr. Be careful nt t let the gear husing cme ff - hld it in place as yu remve the screws. Hld the mtr s that the mtr shaft and gear husing is pinted upward. As yu hld the mtr shaft in place by placing yur finger n the end f the shaft, slide the mtr husing up and ff t expse the internal gearing. Nte the psitin f the gears befre remving any f them. 2

3 REMOVING THE GEARS... Once the gears are expsed, grasp the larger "keyed" mtr shaft and lift it ut f the husing. Be careful as there is a washer/bearing sitting directly n tp f the large black gear and there is a very tiny little washer that ges ver the small spindle at the bttm f the shaft. The gear itself is attached t the shaft and des nt mve. THE MAIN KEYED GEAR AFTER IT IS REMOVED FROM THE HOUSING. BE CAREFUL NOT TO LOOSE THE TWO WASHER- BEARINGS AS PICTURED BELOW. THE INTERNAL GEAR CLUSTER SHOWING THE STOCK STICKY GREASE AND LOTS OF PLASTIC DEBRIS This washer sits n tp f the plastic gear. Main Keyed Shaft Upper Shaft Brass Bushing This washer fits ver small pin at bttm f shaft.. Lwer Shaft 3

4 Remve the large black gear frm the lwer shaft. MAIN SHAFT REMOVED. THE OTHER TWO SHAFTS DO NOT COME OUT - THE GEARS SLIP OVER THE SHAFTS. Remve the large black gear frm the upper shaft. LARGE GEAR FROM UPPER SHAFT LARGE GEAR & BRASS BUSHING FROM LOWER SHAFT Remve the small brass bushing / bearing frm the lwer shaft. Remve the small white gear frm the shaft. Nte: Directly under the brass bushing is anther small washer between the brass bearing and the gear face. The small pinin gear n the mtr shaft des nt cme ff. BRASS BUSHING FROM LOWER SHAFT 4

5 CLEANING THE GEARS... I used a white (easy t see small washers that drp ff f the shafts and gears while cleaning) cl whip cntainer (cause I like cl whip) with abut 3/4" f fresh turpentine (mineral spirits will als wrk) and an ld tthbrush t clean the sticky riginal grease frm the gears. Once cleaned, it's time t re-lube and re-install the gears in the reverse rder f remval. I've tried several different lubricants and had settled n white lithium grease but change happens and I have nw changed my "preferred" lubricatin t SuperLube. It is 100% synthetic, clear, resists water, has PTFE particle suspensin, des nt run and is super slick. Yu can read mre abut here: Once yu have the gears lubed up and back in place, carefully put the gear casing back in place and tighten dwn the tw screws hlding it in place. Turn the encder end f the shaft a cuple f times t ensure yu have nthing binding and smth rtatin. (I tuched the tw bare ended mtr windings t a AA battery t allw the mtr t turn a few rtatins - reverse the wires t rtate it in the ppsite directin - and cnfirmed all was perating as it shuld). REASSEMBLE THE MOTOR... Fllw the directins in reverse till yu have the mtr munted back inside the husing. Slder the cnectins t the mtr wires, remunt the cntrller bard (dn't frget the spacers under the bard), plug the tw red/black wire plug back in place with the red wire twards the middle f the bard (away frm the encder) and yu are finished. Enjy Smther - Quieter mtring! GOOD ENCODER POSITIONING WITH.09MM ALLEN KEY I purchased mine frm: Nte: In its ut f the tube r tub frm, SuperLube is extremely gd - althugh a little "stiff". In my munts, I made my wn custm frmulatin by filling a sht glass almst t the rim with the SuperLube and then adding abut 3/4 f a cap f 100% pure synthetic mtr il (Mbile 1, Penzil, etc - just make sure it is NOT a blend but 100% synthetic). Mixing this up gave me a very nice viscsity which gave super smth buttery like mvement in all parts f my munt with n running and n breakdwn. Re-assemble the gear bx in reverse rder adding lubricant t each shaft, each washer/ bearing, each gear face all gear teeth. Make sure t put a large dab n the end f each shaft, n the inside f the gear husing where the indents are t hld the gears and n the mtr pinin gear. I was nt afraid t use a lt f lube as the gear bx is pretty much sealed and the SuperLube des nt run - I cvered the whle gear cluster with lube. BLACKENED ENCODER WHEEL USING SEVERAL EXTREMELY LITE COATS OF ULTRA FLAT BLACK MIST. DRIVE GEARS REPLACED WITH WARPSDRIVE BELT CONVER- SION TIMING PULLEYS Feel free t me if yu have any questins at: warpcrp@swbell.net 5